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Biogenic Synthesis of ZnO Nanoparticles and Their Application as Bioactive Agents: A Critical Overview

Maria Chiara Sportelli
Caterina Gaudiuso
Annalisa Volpe
Margherita Izzi
Rosaria Anna Picca
Antonio Ancona
2,3,* and
Nicola Cioffi
Chemistry Department, University of Bari, Via Orabona 4, 70126 Bari, Italy
Institute of Photonics and Nanotechnology-National Research Council (IFN-CNR), Via Amendola 173, 70126 Bari, Italy
Physics Department, University of Bari, Via Orabona 4, 70126 Bari, Italy
Centre for Colloid and Surface Science (CSGI), University of Bari Aldo Moro, 70125 Bari, Italy
Authors to whom correspondence should be addressed.
Reactions 2022, 3(3), 423-441;
Submission received: 29 June 2022 / Revised: 23 July 2022 / Accepted: 11 August 2022 / Published: 17 August 2022
(This article belongs to the Special Issue Nanoparticles: Synthesis, Properties, and Applications)


Zinc oxide is a safe material for humans, with high biocompatibility and negligible cytotoxicity. Interestingly, it shows exceptional antimicrobial activity against bacteria, viruses, fungi, etc., especially when reduced to the nanometer size. As it is easily understandable, thanks to its properties, it is at the forefront of safe antimicrobials in this pandemic era. Besides, in the view of the 2022 European Green Deal announced by the European Commission, even science and nanotechnology are moving towards “greener” approaches to the synthesis of nanoparticles. Among them, biogenic ZnO nanoparticles have been extensively studied for their biological applications and environmental remediation. Plants, algae, fungi, yeast, etc., (which are composed of naturally occurring biomolecules) play, in biogenic processes, an active role in the formation of nanoparticles with distinct shapes and sizes. The present review targets the biogenic synthesis of ZnO nanoparticles, with a specific focus on their bioactive properties and antimicrobial application.

1. Introduction

In recent years, various metal oxide nanoparticles (MONPs) revived interest for a plethora of different applications, specifically when a green experimental approach is proposed [1]. To meet the increasing demand of such NPs, many different methods have been established. Amongst MONPs, zinc oxide NPs (ZnONPs) got unique attention due to their distinctive properties, which make them useful for many different real-life applications. In particular, the biosynthesis of ZnONPs has been proposed, mostly in the last 10 years, as a cheap and environment-friendly option to chemical and physical methods, due to concerns about climate change, water pollution, limited natural resources, toxicology, and so on [2]. A detailed bibliographic search on the Scopus® database confirms the constantly growing interest on the topic (Figure 1). Despite the low cost and need for simple equipment in such processes, long reaction time and the use of nonaqueous media are considerable disadvantages of common chemical routes [3]. In place of these classical methods, “green” and “soft” synthesis approaches are constantly needed to develop tunable ZnO nanomaterials. Ideally, these novel methods should also be cost and time effective in comparison to other available protocols: from a brief analysis of the retrieved literature, research is moving towards these principles [4,5].
The USA Food and Drug Administration (FDA) has registered ZnO as a “GRAS” (generally recognized as safe) material [6]. This is why ZnONPs already find applications in several fields of medicine, industry, food, agriculture, and electronics. Many of them have been recently reviewed by Prasad et al. [5]; thanks to their intrinsic biocompatibility, biogenic ZnONPs have been extensively studied for their biological applications and environmental remediation. The synthesis of NPs, with control over particle size, shape, and crystallinity, has been one of the main objectives in materials chemistry. Nature provides ways and insight into the synthesis of advanced and eco-friendly nanomaterials. About three decades ago, the first reports about biological systems, which could act as “bio-laboratories” for the production of metal and metal oxide particles at the nanometer scale, was envisaged [7,8]. Looking throughout the literature on biogenic synthesis, despite the source of biomolecules that is used, reaction yields are basically never explicated. We believe this is mainly due to the intrinsic variability of each biogenic reaction mixture, which can deeply influence reaction yields and NP properties [9].
Various microorganisms, such as bacteria [10] and fungi [11], along with plant extracts [12] have acted as green chemicals towards NPs. Surprisingly, waste from agrifood industries of food supply chains have been used as chemicals too; these molecules allow for the preparation of NPs without the use of dangerous chemicals and ensure the reuse and reduction in wastes in the view of a circular economy.
During biogenic syntheses, biomolecules generally act both as reducing agents for metal precursors, and capping agent for as-prepared NPs. This “layer” of biological molecules surrounding NPs, is often proposed as a way to confer the high biocompatibility and negligible toxicity in comparison with NPs prepared by classic chemical methods [5]. The biocompatibility of biogenic ZnONPs may offer very interesting applications in biomedicine and prevention of microbial contamination. It is worth pointing out that biogenic procedures may also have some drawbacks. Being, in most cases, the exact biochemical composition of the reaction mixture unknown, it is not possible to foresee which byproducts and wastes could be developed during the process [13]. Additionally, some of these synthetic protocols could need a large amount of solvent (water, in most cases) for obtaining phyto-extracts with a non-negligible environmental impact [14].
Vegetable extracts (from plants, fruits, spices and herbs, flowers), algae and seaweeds, and metal-tolerant bacteria are the most used source for reactants exploited in recent papers on the topic (Figure 2) [15].
The aim of this review is not a comprehensive listing of all the existing literature about the biosynthesis of ZnONPs, but a critical discussion of the most recent papers, with specific attention towards the use of these NPs as antimicrobial and/or antiviral agents. This review article will not cover heteroatom-doped ZnO nanomaterials. Each reactant source will be discussed in a dedicated paragraph; main results on the bioactive properties of ZnO will be examined as well, lining out the importance of this material during the coronavirus pandemic. A list of recent review papers (2021–2022) on this topic is reported in Table 1.

2. Phyto-Mediated Synthesis: Plants and Flowers

Among green biosynthesis routes, plant-mediated ones got expanding consideration; many plant extracts contain a large amount of phytochemicals, which can act both as reducing agents and capping/stabilizing molecules [16]. Since the 1990s, the use of plants and plant-derived substances, in the ZnONPs synthesis, was proposed to lessen remarkably the requirement of expensive chemicals with limited availability, and hazardous experimental protocols [17]. ZnONP production from plant extracts is easily scalable and then highly appealing for industrial and technological use. Furthermore, this approach is extremely straightforward. Briefly, a zinc salt (mainly zinc nitrate, chloride, or acetate) is added to a plant extract; after a proper reaction time (catalyzed, when appropriate, by sunlight or other energy sources), the produced suspension is washed and subjected to thermal treatments to have stoichiometric ZnO nano- or micro-powders [18]. Preparation of the plant extract is pivotal for a synthesis with sufficient yield. The leaves (or any further plant part) first go through pretreatment processes. The latter are the most important means for the extraction of phytochemicals to deliver the phyto-mediated synthesis. During this step, vegetable cells are disrupted to allow for the release of active molecules. A number of steps are typically necessary [15]:
Plant parts are rinsed with water.
Plant parts are then sliced into smaller parts and then grinded in a mortar or ball-milled (the choice depends on the nature of the plant part). The obtained material can either be used itself or subjected to solid–liquid extraction (boiling, soxhlet, etc.).
Mixture is filtered to remove the solid component.
Plant extract can then be used for NP synthesis (sometimes a pre-concentration step is necessary).
Figure 3 reports a detailed scheme of the process.
A fascinating review was published in 2021 on phytogenic ZnONPs, synthesized using various molecules as reductants of organic and inorganic Zn salts, as well as their production, characterization and biocompatibility, which explains their present request for dermo-pharmaceutical and cosmetic products [19].
Table 1. Main reviews on biogenic synthesis of ZnONPs published in 2021–2022.
Table 1. Main reviews on biogenic synthesis of ZnONPs published in 2021–2022.
Source of Biological ReactantsYearApplicationsRef.
Microbes/bacteria2022Biomedical, agricultural, environmental[20]
Plant extracts2022Antimicrobial[21]
Microorganisms, plant extracts, algae2022Gas Sensing[22]
Microorganisms, plant extracts2022Fertilizers[23]
Plant extracts2022Biomedical[24]
Microorganisms, plant extracts2022Biomedical, (bio)sensing, imaging[25]
Natural extracts2022Pharmacotherapeutics[26]
Fruit peel2022Nutraceutical, biomedical, active coatings, sorbents[27]
Plant extracts2022Anticancer agents[28]
Microorganisms, plant extracts2022Photocatalysis[29]
Microorganisms, plant extracts, algae2021Pollutant removal[30]
Plant parts2021Antimicrobial, anticancer[31]
Marine organisms2021Drug delivery, antimicrobial, (bio)sensing, fertilizers[32]
Microorganisms, plant extracts, algae2021Antibacterial, antioxidant, antidiabetic and tissue regeneration[33]
Biopolymers, plant parts2021Nanocomposite production[34]
Plant extracts2021Environmental[35]
Plant extracts2021Biomedical[36]
Biopolymers, plant parts2021Drug delivery[37]
One of the most remarkable cases of ZnONPs made for this aim concerns the use of Salvia Officinalis [38,39]. It is crucial to state that this is a medicinal plant that grows in most of the continents, and its pharmacologic benefits have been extensively recognized [40]. The major phytochemical composition of S. officinalis comprehends glycosidic derivatives (such as flavonoid glycosides, cardiac glycosides, coumarins, tannins, and saponins), steroids, terpenes/terpenoids (including sesquiterpenoids, monoterpenoids, diterpenoids, and triterpenoids), mostly found in leaves and flowers [41]. The synergic antimicrobial effect of ZnONPs prepared from salvia extracts has been recently demonstrated [39].
Still talking about dermo-pharmaceutical and cosmetic interest towards ZnONPs, Aloe vera leaf extracts have been used as reducing and capping agents too. Recently, Batool et al. [42] reported about that Aloe leaves contain a gelatinous material (commonly used as balm and humectant) which holds vitamins A and C, folic acid, β-carotene antioxidants, and some trace elements, such as Ca, Cu, Mg, K [43]. All these substances, along with chemicals, such as salicylic acid and anthraquinones, make this extract very attractive for cosmetic and pharmaceutical formulations, guaranteeing a potent reducing power as well [44].
Regarding the specific case of flowers, acetonic extracts are generally used, i.e., extracts made using acetone as solvent. Most of the important chemicals coming from flower petals are, indeed, much more soluble in this solvent rather than in aqueous solutions [45,46]. Flowers have a very high amount of flavonoids (>4%w/w), which are crucial in NPs synthesis and have good stabilizing/capping properties [47]. Many flowers have been exploited in 2021 and 2022 for the preparation of ZnONPs: Geranium robertianum [47], Camelia sinensis and Datura Stramonium [48], Lantana camara [49], Rhaponticum repens [50], Tagetes erecta [51], Gardenia thailandica [52], Malva Parviflora [53], Parthenium histerophorus [54], just to cite a few.
Recently, tree bark was also used for the preparation of ZnONPs; in a paper from Parveen et al. [55], ZnO was exploited as nano-fertilizer for the cultivation of different rice varieties.
An enormously wide plethora of flowers, plants, and extracts have been suggested to accomplish the green synthesis of ZnONPs [56]. A comprehensive list of these procedures goes beyond the aim of this review. However, it is worth stating that the ultimate preference of a specific phyto-extract is mostly determined by the local vegetation, i.e., from accessibility of some vegetable types in certain areas. Based on the singular chemical composition of every plant extract, several shapes on ZnO-based nanostructures were achieved, varying from spheroidal particles (which are most common), to rod-like and flower-like ones [57]. Physicochemical properties of the obtained particles are a function of the phyto-extract as well [58].
The exact mechanism of plant-mediated synthesis tightly depends of the (peculiar) chemical nature of each extract and is still unanswered in most cases.

3. Algae and Seaweeds

Although less common, seaweeds and cellular algae have been employed for the green synthesis of metal oxide NPs [59] as well. Algae are sea microorganisms that have been reported not only to uptake heavy metals from the environment, but also to synthesize metal NPs [60]. Many seaweed species possess similar properties [61]. These sources are environmentally amenable and are the proficient biological sources for the preparation of ZnONPs [62]. Seaweeds are characterized by a higher amount of polysaccharides [63], as compared to plant extracts; the presence of these compounds ensures a very high capping and/or chelating capacity on produced NPs [64]. Polysaccharides are thought to be involved in the conversion of −OH (alcoholic groups) into –CHO (aldehydic groups) through oxidation, which results in the reduction of precursor zinc ions into elemental oxidation state. Spontaneous oxidation of the as-prepared NPs brings the final chemical state to ZnO (Figure 4) [62]. The powdered extract of Gracilaria edulis was proficiently applied for the preparation of ZnO nanorods (NRs). Quinine, highly present in the aqueous extract of this seaweed, is regarded as the main reducing agent in the production of ZnONPs. Quinines are biomolecules with a very high redox potential, successfully used as reducing agents for metal ions in various papers [65]. In 2021, Alsaggaf et al. proposed the synthesis of ZnONPs using a green phenol-rich extract from Ulvaceae, a widely available macroalga in the Mediterranean Sea; these ZnONPs were successfully used as active layers for the preservation of seafoods [66]. A similar approach was also followed by Anjali et al. [67] and Thirumoorthy et al. [68] for antibacterial, antifungal, and anticancer purposes [69]. Algae-mediated synthesis of ZnONPs was also described by Subramanian et al. [70]; brown seaweed Sargassum muticum was collected at a marine biodiversity hotspot area along the Gulf of Mannar coastline, in the eastern coastal region of Tamil Nadu, India. ZnONPs were used here for both the photo-degradation of methylene blue dye under different light conditions, and as wide-spectrum antimicrobial agents against multidrug-resistant bacteria [71]. Another brown alga named Dictyota dichotoma was analogously exploited to prepare antimicrobial ZnONPs [72].
To the best of our knowledge, one of the few systematic studies on the effect of synthetic parameters and provenance of seaweed extracts on the final physicochemical properties of ZnONPs is that from Nagarajan et al., published in 2013 [73]. They rationalized the effect of seaweed extract concentration, temperature, pH, and reaction time. The composition of extracts coming from three different species were compared, e.g., green Caulerpa peltata, red Hypnea valencia, and brown Sargassum myriocystum.
The rich biodiversity and easy availability of algae and seaweeds, which do not require any direct “plant care” from humans, has not been exploited exhaustively for nanomaterials synthesis yet, and we believe that this approach will flourish in the near future.

4. Foods and Herbs

Another class of bio-mediated syntheses regards the use of food wastes and herbs. Most wastes contain phenolic compounds, low-molecular-weight secondary metabolites, which act as protective agents from oxidative damage and possess antimicrobial properties. These phenolic compounds include anthocyanins, flavonoids, tannins, alkaloids, gallic acid, ferulic acid, chlorogenic acid, catechin, epicatechin, saponins, and their content in waste depends on the type and profile of the (agri-)waste itself [74]. More specifically, fruits peel and pulp generally contain reducing sugars [75], which can effectively reduce metal precursors. Similarly, edible vegetables and nuts contain terpenoids, polysaccharides, and aromas with both reducing and stabilizing properties [76]. Lignin is another polyphenolic compound (present in high amount in grape stalks, as an example) which has been successfully used for the production of metal oxide NPs [74].
The active components can be extracted by the use of aqueous, organic or mixed solvents. The solvent is added to the food waste, and batch extraction is performed at a low temperature (generally about 50 °C, with some molecules being thermolabile). The liquid-solid suspension is generally made by a 20:1 ratio between solvent and solid waste and is stirred at fixed temperature for about 1–2 h. The solution is then filtered, centrifuged, and the extract is then ready for NPs synthesis. The extract can also be stored for future use at a temperature of about 0–4 °C [77].
Only during 2021 and 2022, many different examples can be found in the literature, ranging from fruit peels, such as papaya [78], pomegranate [79], myrica [80], coconut [81], dates [82], mulberry [83], orange [84,85], and banana [86], to olives [87], grounded coffee [79], turnip and raphanus discards [88,89], spinach [90], nut shells and leaves [91,92], and so on.
A wide variety of herbs has been used to the same aim. In this case, odorous molecules can play the role of reductants and stabilizing agents to ZnONPs. These MONPs are widely used as food-preserving packaging to extend the shelf life of perishable foods; some examples have been recently published about guava fruit [93] and ichthyic products [94], exploiting nettle leaf extracts [95]. Lemongrass leaves were successfully used for the production of active ZnONPs against human ticks with slight toxicity for people [96]. Thanks to its semiconducting properties, ZnO can be also applied for sunlight protection in both cosmetics and industrial fields. An interesting piece of research from Asmat-Campos et al. reported on the biosynthesis of ZnONPs with coriander as a reducing agent with high biosafety [97]. Biomedical applications can be found for food-derived ZnO nanostructures with thymus [98] and onion [99]; curcumin-stabilized NPs were used for sensing applications [100] and mint-produced ones for energy storage [101] as well. S. Vijayakumar used paprika extracts for rod-shaped ZnONPs with strong antimicrobial activity [102]. El Golli et al. [103] prepared wurtzite ZnONPs using garlic bulb extracts, with a good morphological control (Figure 5) for photocatalytic applications. Mbenga et al. [104] prepared ZnONPs from garlic extracts as well, which displayed a high cytotoxicity on human liver cells.
Recently, onions were used for the preparation of small ZnONPs [105]; they were revealed to be extremely toxic for the aqueous environment, with massive bioaccumulation in carp gills and alteration of antioxidants gene expression, in addition to a 100% mortality recorded at the maximum tested concentrations of 10 mg/L at 96 h. This example demonstrates how “biogenic” is not necessarily equivalent to “safe”.
The valorization of food waste, e.g., through conversion into useful chemicals for NPs synthesis, is a beneficial option in terms of economics, sustainability, and social and environmental impacts. This important contest requires methodical and complex biochemical process design and optimization, to ensure that the extraction methods are energy efficient, economically viable, and with a negligible environmental impact. This requires an interdisciplinary approach, involving experts in food science, chemists, materials scientists, etc., to find a suitable design with minimum cost and maximum benefit [106].

5. Bacteria and Microorganisms

The bacteria-mediated synthesis of ZnONPs is much less common. In this case, a metal precursor should be added to a bacterial culture in planktonic state. Enzymes and proteins exert the reducing action [57]. Recently, studies demonstrated the spotlight role of extracellular enzymes in biogenic synthesis, recognized specifically in nicotinamide adenine dinucleotide (NADH) and its reduced form of nicotinamide adenine dinucleotide phosphate (NADPH). These enzymes are fundamental for electron transfer between cofactor NADH to NADH-dependent enzyme (in the reduction process), thus acting as electron carriers (Figure 6) [107]. Elemental Zn0, produced by the reduction of salt precursors is then spontaneously oxidized again to form water-insoluble ZnO, by dissolved oxygen.
Due to a certain antimicrobial action exerted by metal/metal oxide NPs, it is necessary to use metal-tolerant [108] and thermophilic [109] bacterial strains. In order to respect the non-harmful principle of green chemistry, bacterial strains should be non-pathogenic, too. For example, in the last year, ZnONPs were prepared through Pseudochrobactrum sp. suspension for the degradation of organic dyes in the textile industry [110]. A similar approach was also used for the preparation of ZnONPs against parasites of rice cultures with Bacillus cereus [111] and cyanobacteria, such as spirulina (i.e., Arthrospira platensis) [112].
Recently, Faisal et al., reported on the bio-mediated synthesis of ZnONPs using a novel bacterial strain named Paraclostridium sp. [113]. They demonstrated the efficacy of the produced NPs in a wide plethora of in vivo biomedical applications: Helicobacter eradication, anti-inflammatory, anti-diabetic, anti-arthritic, and anti-diabetic efficacy.
An up-to-date, comprehensive listing of all the microorganisms used for ZnONP synthesis has been recently published in a specific review paper on microorganism-mediated NPs syntheses [114].
From the aforementioned papers, it is clear that only few microorganisms have the ability to synthesize ZnONPs [115]. Hence, there is a demand to discover more prospective biogenic substrates for the synthesis of these nanomaterials. Biological synthesis using bacteria/yeasts offers an advantage over plants, fruits, etc., since microbes are easily reproduced. Nonetheless, there are many drawbacks pertaining to the isolation and screening of potential microbes. The main disadvantage however resides in the fact that the process is time consuming and involves the use of expensive chemicals for microorganisms growth medium. The presence of various enzymes, proteins, and other biomolecules from microbes plays a crucial role in NP production process. These multiple organic components, secreted in the suspension or growth medium, are responsible for the formation of NPs with multiple sizes and shapes. Moreover, some proteins produced from microbes could behave as capping agents, thus increasing the stability of ZnONPs [116]. The specific mechanism of nanoparticle formation by microbial extracts is the most critical unanswered issue in the biosynthesis approach. It is striking that identifying specific biomolecules present in microbes, responsible for NPs formation, may support improvements to the synthetic method [117]. Large scale production with lower reaction times and reduced solvents amount is researchers’ final goal. However, most of the papers available in the literature show that NPs are produced thanks to the synergistic co-action of several biomolecules or metabolites present in the microbial extracts or growth medium [118].
The biological synthesis of ZnONPs needs more time to reach pre-commercialization steps and then coming to the market. Pilot scale demonstrators are pivotal in transforming the results of the (nano)biotechnological research into competitive manufacturing. Hence, as biogenic nanotechnology is at its nascent stage, there are understandably still few investors taking the risk in early stage innovation [119].

6. Application of ZnONPs as Antimicrobial and Antiviral Agents

Thanks to the presence of natural compounds, ZnONPs synthesized by biogenic methods are generally considered highly biocompatible; this evidence lays beyond the large use of these NPs as antimicrobial agents with negligible cytotoxicity [120,121,122,123,124,125,126,127,128,129]. For the same reasons, they have been widely investigated in recent years as new-generation anti-cancer and antioxidants drugs [130] with very promising results and much less side effects in respect to other metal-based medications [131,132,133,134,135,136,137,138]. A detailed study confirming the high antimicrobial and antifungal activity of these NPs against food pathogens, with limited cytotoxicity, was recently published, exploiting food derivatives for their biogenic synthesis [139]. It is worth underlining that not all biogenic ZnONPs show antimicrobial activity; a peculiar case was shown by Dey et al., who prepared ZnONPs with leaf extracts and tested them against both gram-positive and negative bacteria with no success [140].
Some other papers reported on the technological application of biosynthesized ZnONPs, such as photocatalytic wastewater treatment [141,142], gas [143], and electrochemical [49] sensors, catalysis [144], etc. This kind of application is less diffuse because it generally requires a good morphological control and a well-known chemical composition; these conditions are quite complex to be achieved with biogenic-mediated synthetic routes.
During the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, nanomaterials, and ZnONPs specifically, were revealed to be powerful allies in the prevention of viral infections [145]. Beside the novel SARS-CoV-2, there are other viruses responsible for respiratory diseases, such as other coronaviruses, syncytial virus, rhinovirus, and influenza virus, whose contagion capacity have caused former pandemic outbreaks, as well as viral seasonal outbreaks where prophylaxis and prevention play a determining role [146]. In this scenario, the search for wide-spectrum antiviral agents, with restrained side effects for humans, becomes fundamental. Since the size of these viruses falls in the nanoscale, nanotechnology and materials science possess an enormous potential to interact with viruses lifecycle [147]. Additionally, they can deliver new chances in the development of safer personal protective equipment (PPE) and new effective therapeutic solutions [148]. Besides, in antiviral strategies aimed at preventing viral infection (disinfecting or anti-contamination materials, blocking viral docking to host cells, self-cleaning common touch surfaces, etc.), NPs, which are generally able to carry proteins, drug molecules, and a variety of other chemical compounds, are also used for drug delivery and diagnostic or therapeutic tools [149]. This pandemic revealed the need to keep surfaces clean and uncontaminated. Due to the inability of many viruses to spread outside the body (e.g., human immunodeficiency virus, HIV), viral transmission through surfaces have attracted little attention in the past. However, SARS-CoV-2 can remain viable on surfaces for days [150], and this poses a great risk for transmission via surface route, highlighting the critical need for efficient solutions that avoid the survival of viruses on surfaces [151]. Anti-infective surfaces can have different mechanisms of action, which are direct disinfection, indirect disinfection, and receptor inactivation [152]. Zn-based nanomaterials were proven to be efficient antimicrobials that offer various significant photocatalytic, surface, and morphological properties to inhibit and deactivate viruses at all the aforementioned levels. In other words, ZnONPs exhibit tunable antibacterial, antifungal, and antiviral capacities. Although the mechanism of action of ZnONPs as an antibacterial and antifungal agent has been determined [153,154], the antiviral one is still under study. A recent report hypothesized virus inactivation by Zn2+ release and ROS formation (Figure 7).
The authors pointed out that the same mechanisms for antibacterial activity are also responsible for damaging the lipid membrane and RNA, thereby inactivating the virus [155]. These same pathways were hypothesized for ZnONPs prepared by Plumbago indica alcoholic leaf extract, against Herpes Simplex Virus Type 1 (HSV-1). Plumbago indica leaf extract is considered a valuable source for various types of active compound, such as alkaloids, phenolics, and saponins [156].
The effectiveness of ZnONPs was firstly predicated by in-silico models in early 2021; specifically, the effect of hesperidin (from food wastes) in combination with ZnONPs was demonstrated theoretically, with a significant synergistic effect (e.g., hesperidin-mediated ZnONPs exhibited higher antiviral activity than hesperidin itself) [157]. Hamdi et al. [158] performed a detailed computational analysis of the possible interaction between ZnONPs and SARS-CoV-2 targets, including the ACE2 receptor, RNA-dependent RNA polymerase, and main proteases. ZnONPs cellular internalization in human lung fibroblasts was also assessed. The highest antiviral activity was predicted for hexagonal and spherical ZnO nanostructures with a crystallite size of around 11 nm and positive z-potential. Interestingly, successful binding between ZnONPs and viral molecular targets, via hydrogen bond formation, was detected. Based on this evidence, ZnONPs have been extensively used for the production of face masks or (respiratory) filters for the inactivation of virions before their entry in human cells.
ZnONPs were immobilized in polyethylene oxide (PEO) matrix, for the modification of common touch surfaces, with exceptional results of virus inactivation; in [159] we demonstrated that ZnO nano-powders were effective in lowering the quantification of nucleocapsid (N) protein in virus samples from nasopharyngeal swabs.
Composites, based on polyacrylonitrile (PAN) nanofibers modified with ZnONPs, were used to remove air pollutants and microbes (bacteria and respiratory viruses) with application in masks, cleanrooms, and indoor air purification [148]. ZnONPs were also grown directly within textile and face mask materials, including polypropylene (PP) and nylon–cotton. This novel filtering material achieved a ≥99.9% reduction in SARS-CoV-2 titer within a contact time of 10 min, by disintegrating the viral envelope. Additionally, the new ZnO-modified textile could retain its antiviral properties even after 100 laundry cycles, and was dermatologically tested as non-irritant and hypoallergenic [160]. Analogously, surface modification of both touching surfaces and air filters was performed by Merkl et al. with significant limitation of airborne viral transmission from aerosols [161].
We believe it is worth describing the paper by El-Megharbel and co-workers [162], which despite the synthesis of ZnONPs cannot be considered specifically green. They reported on the production of ZnO-based nano-sprays for surfaces disinfection against SARS-CoV-2, with negligible cytotoxicity.
Berberine-capped ZnONPs were successfully prepared by Ghareeb et al. [163]. Berberine is a quaternary ammonium salt found in the roots of some plants, such as barberry or turmeric, which possesses pharmacological properties, including antioxidant and antimicrobial ones. In the above mentioned work, berberine-capped ZnONPs were found to be effective in the treatment of bacterial nosocomial infections associated with SARS-CoV-2. Still talking about pharmacological applications, a vaccine against SARS-CoV-2 based on the antiviral properties of Zn2+ ions was recently proposed by Ishida [164].
Safety worries related to shopping in supermarkets during the SARS-CoV-2 pandemic has headed to a predilection for fresh-food packaged in plastic containers by consumers and sellers, as well as the usage of disposable food packaging and plastic bags to carry groceries. In order to address these concerns, active packaging with antiviral properties was proposed. ZnONP-modified packaging material was described in 2021 [165]; specifically, NPs surfaces were here functionalized with geraniol and carvacrol thus obtaining an antimicrobial material with synergistic action against common food pathogens and SARS-CoV-2, simultaneously.
Nanotechnology-based tools play a key role in improving infections treatment and prevention. These materials can effectively help in the current global public health challenge, by delivering exactly the type of wide-ranging, easily scalable, low-harmful, combined tactics that are indispensable to manage and control the SARS-CoV-2 plague. Nanotechnology can offer appropriate and more efficient approaches to dealing with SARS-CoV-2, or other emerging viral or bacterial pandemics, which could occur in the future.

7. Conclusions

This review outlines how the biogenic and green synthesis of (ZnO) nanomaterials is becoming more and more important in an industrial and scientific context. Our purpose was not to provide a comprehensive enumeration of all available studies on this topic; we meant, instead, to describe selected and extremely recent examples, elucidating which synthetic route could be more suitable for a precise application, or to address a specific problem. We focused purposely quite exclusively on papers published during the last two years, in order to provide a point of view in steps with the times.
We believe that the research field reviewed here will certainly undergo further growth in the next years, and we hope the readers will find the information provided useful. Among the reviewed approaches to the biogenic production of ZnO nanocolloids, the syntheses based on renewable and waste-reuse sources might receive massive attention in the coming years, due to their scalability to industrial processes and the invaluable advantages in reducing energy consumption and environmental impact related to organic solvents and harmful reagents.
Thanks to scientific research, and to a strong collaboration between industries and academia, it will be possible to deepen the knowledge about green synthetic routes for the preparation of helpful nanomaterials, such as ZnO, with reduced risks for humans and environments.

Author Contributions

Conceptualization, M.C.S., M.I. and R.A.P.; investigation, M.C.S.; resources, A.A. and N.C.; writing—original draft preparation, M.C.S.; writing—review and editing, M.C.S., A.V., C.G., M.I., R.A.P., A.A. and N.C.; supervision, A.A. and N.C.; funding acquisition, A.A. and N.C. All authors have read and agreed to the published version of the manuscript.


M.C.S. acknowledges the financial support from Fondo Sociale Europeo “Research for Innovation (REFIN)”; project n° 435A866B. C.G. acknowledges the financial support from Fondo Sociale Europeo “Research for Innovation (REFIN)”, project n° FEB1B50F. N.C. acknowledges the European Union–NextGenerationEU, “MUR-Fondo Promozione e Sviluppo—DM 737/2021” program, grant H99J21017320006, S12, Materiali e soluzioni tecnologiche per la riduzione della persistenza del SARS-CoV-2 ed il suo monitoraggio bioelettronico. Partial financial support is acknowledged by Italian MIUR for National Project PON E-DESIGN (ARS01_01158).

Conflicts of Interest

The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.


  1. Sportelli, M.C.; Scarabino, S.; Picca, R.A.; Cioffi, N. Recent Trends in the Electrochemical Synthesis of Zinc Oxide Nano-Colloids. In CRC Concise Encyclopedia of Nanotechnology; CRC Press, LLC: Boca Raton, FL, USA, 2015; pp. 1158–1172. ISBN 978-1-4665-8034-3. [Google Scholar]
  2. Agarwal, H.; Venkat Kumar, S.; Rajeshkumar, S. A Review on Green Synthesis of Zinc Oxide Nanoparticles—An Eco-Friendly Approach. Resour.-Effic. Technol. 2017, 3, 406–413. [Google Scholar] [CrossRef]
  3. Srivastava, S.; Usmani, Z.; Atanasov, A.G.; Singh, V.K.; Singh, N.P.; Abdel-Azeem, A.M.; Prasad, R.; Gupta, G.; Sharma, M.; Bhargava, A. Biological Nanofactories: Using Living Forms for Metal Nanoparticle Synthesis. Mini Rev. Med. Chem. 2021, 21, 245–265. [Google Scholar] [CrossRef]
  4. Arya, S.; Mahajan, P.; Mahajan, S.; Khosla, A.; Datt, R.; Gupta, V.; Young, S.-J.; Oruganti, S.K. Review—Influence of Processing Parameters to Control Morphology and Optical Properties of Sol-Gel Synthesized ZnO Nanoparticles. ECS J. Solid State Sci. Technol. 2021, 10, 023002. [Google Scholar] [CrossRef]
  5. Prasad, A.R.; Williams, L.; Garvasis, J.; Shamsheera, K.O.; Basheer, S.M.; Kuruvilla, M.; Joseph, A. Applications of Phytogenic ZnO Nanoparticles: A Review on Recent Advancements. J. Mol. Liq. 2021, 331, 115805. [Google Scholar] [CrossRef]
  6. Food and Drug Administration; Department of Health and Human Services FDA. Code of Federal Regulations, Title 21: Zinc Oxide. Available online: (accessed on 28 May 2021).
  7. Beveridge, T.J.; Fyfe, W.S. Metal Fixation by Bacterial Cell Walls. Can. J. Earth Sci. 1985, 22, 1893–1898. [Google Scholar] [CrossRef]
  8. Fendler, J.H. Biomineralization Inspired Preparation of Nanoparticles and Nanoparticulate Films. Curr. Opin. Solid State Mater. Sci. 1997, 2, 365–369. [Google Scholar] [CrossRef]
  9. Mondal, A.; Umekar, M.S.; Bhusari, G.S.; Chouke, P.B.; Lambat, T.; Mondal, S.; Chaudhary, R.G.; Mahmood, S.H. Biogenic Synthesis of Metal/Metal Oxide Nanostructured Materials. Curr. Pharm. Biotechnol. 2021, 22, 1782–1793. [Google Scholar] [CrossRef]
  10. Stephen, J.R.; Macnaughtont, S.J. Developments in Terrestrial Bacterial Remediation of Metals. Curr. Opin. Biotechnol. 1999, 10, 230–233. [Google Scholar] [CrossRef]
  11. Khalil, A.T.; Ovais, M.; Ullah, I.; Ali, M.; Shinwari, Z.K.; Khamlich, S.; Maaza, M. Sageretia thea (Osbeck.) Mediated Synthesis of Zinc Oxide Nanoparticles and Its Biological Applications. Nanomedicine 2017, 12, 1767–1789. [Google Scholar] [CrossRef]
  12. Narendra Kumar, H.K.; Chandra Mohana, N.; Nuthan, B.R.; Ramesha, K.P.; Rakshith, D.; Geetha, N.; Satish, S. Phyto-Mediated Synthesis of Zinc Oxide Nanoparticles Using Aqueous Plant Extract of Ocimum americanum and Evaluation of Its Bioactivity. SN Appl. Sci. 2019, 1, 651. [Google Scholar] [CrossRef]
  13. Duran, N.; Seabra, A.B. Biogenic Synthesized Ag/Au Nanoparticles: Production, Characterization, and Applications. Curr. Nanosci. 2018, 14, 82–94. [Google Scholar] [CrossRef]
  14. Bandala, E.R.; Stanisic, D.; Tasic, L. Biogenic Nanomaterials for Photocatalytic Degradation and Water Disinfection: A Review. Environ. Sci. Water Res. Technol. 2020, 6, 3195–3213. [Google Scholar] [CrossRef]
  15. Huang, Y.; Haw, C.Y.; Zheng, Z.; Kang, J.; Zheng, J.-C.; Wang, H.-Q. Biosynthesis of Zinc Oxide Nanomaterials from Plant Extracts and Future Green Prospects: A Topical Review. Adv. Sustain. Syst. 2021, 5, 2000266. [Google Scholar] [CrossRef]
  16. Kalpana, V.N.; Devi Rajeswari, V. A Review on Green Synthesis, Biomedical Applications, and Toxicity Studies of ZnO NPs. Bioinorg. Chem. Appl. 2018, 2018, e3569758. [Google Scholar] [CrossRef] [PubMed]
  17. Bandeira, M.; Giovanela, M.; Roesch-Ely, M.; Devine, D.M.; da Silva Crespo, J. Green Synthesis of Zinc Oxide Nanoparticles: A Review of the Synthesis Methodology and Mechanism of Formation. Sustain. Chem. Pharm. 2020, 15, 100223. [Google Scholar] [CrossRef]
  18. Akintelu, S.A.; Folorunso, A.S. A Review on Green Synthesis of Zinc Oxide Nanoparticles Using Plant Extracts and Its Biomedical Applications. BioNanoScience 2020, 10, 848–863. [Google Scholar] [CrossRef]
  19. Paiva-Santos, A.C.; Herdade, A.M.; Guerra, C.; Peixoto, D.; Pereira-Silva, M.; Zeinali, M.; Mascarenhas-Melo, F.; Paranhos, A.; Veiga, F. Plant-Mediated Green Synthesis of Metal-Based Nanoparticles for Dermopharmaceutical and Cosmetic Applications. Int. J. Pharm. 2021, 597, 120311. [Google Scholar] [CrossRef]
  20. Gomaa, E.Z. Microbial Mediated Synthesis of Zinc Oxide Nanoparticles, Characterization and Multifaceted Applications. J. Inorg. Organomet. Polym. 2022. [Google Scholar] [CrossRef]
  21. Sheikh, S.; Mungole, A.J.; Krambe, S. A Review on Plant Extract Mediated Biological Synthesis of Zinc Oxide Nanoparticles and Its Antimicrobial Applications. Int. J. Res. Biosci. Agric. Technol. 2022, 2, 286–289. [Google Scholar]
  22. Dadkhah, M.; Tulliani, J.-M. Green Synthesis of Metal Oxides Semiconductors for Gas Sensing Applications. Sensors 2022, 22, 4669. [Google Scholar] [CrossRef]
  23. Rani, S.; Kumar, P.; Dahiya, P.; Dang, A.S.; Suneja, P. Biogenic Synthesis of Zinc Nanoparticles, Their Applications, and Toxicity Prospects. Front. Microbiol. 2022, 13, 824427. [Google Scholar] [CrossRef] [PubMed]
  24. Abbasi, K.; Khan, F.; Akram, M.; Zainab, R.; Rashid, A.; Kausar, S.; Kesherwani, D.; Parmar, P.; Ravichandran, S.; Rm, M.; et al. Synthesis of Nanoparticles from Plant Extracts. Acta Sci. Microbiol. 2022, 5, 29–35. [Google Scholar] [CrossRef]
  25. Deka, B.; Baruah, C.; Babu, A.; Kalita, P. Biological and Non-Conventional Synthesis of Zinc Oxide Nanoparticles (ZnO-NPs): Their Potential Applications. J. Nanotechnol. Nanomater. 2022, 3, 79–89. [Google Scholar]
  26. Haldar, A.G.M.; Mahapatra, D.K.; Dadure, K.M.; Chaudary, R.G. Natural Extracts-Mediated Biosynthesis of Zinc Oxide Nanoparticles and Their Multiple Pharmacotherapeutic Perspectives. Jordan J. Phys. 2022, 15, 67–79. [Google Scholar] [CrossRef]
  27. Suhag, R.; Kumar, R.; Dhiman, A.; Sharma, A.; Prabhakar, P.K.; Gopalakrishnan, K.; Kumar, R.; Singh, A. Fruit Peel Bioactives, Valorisation into Nanoparticles and Potential Applications: A Review. Crit. Rev. Food Sci. Nutr. 2022; online ahead of print. [Google Scholar] [CrossRef]
  28. Rani, N.; Saini, K. Biogenic Metal and Metal Oxides Nanoparticles as Anticancer Agent: A Review. IOP Conf. Ser. Mater. Sci. Eng. 2022, 1225, 012043. [Google Scholar] [CrossRef]
  29. Bandala, E.R. Chapter 15—Photocatalytic Applications of Biogenic Nanomaterials. In Sustainable Nanotechnology for Environmental Remediation; Koduru, J.R., Karri, R.R., Mubarak, N.M., Bandala, E.R., Eds.; Micro and Nano Technologies; Elsevier: Amsterdam, The Netherlands, 2022; pp. 383–396. ISBN 978-0-12-824547-7. [Google Scholar]
  30. Pang, C.Y.; Issabayeva, G.; Ning, K.L.Y.; Chu, W.M. Synthesis and Applications of Zinc Oxide for Removal of Various Pollutants: A Review. IOP Conf. Ser. Earth Environ. Sci. 2021, 945, 012044. [Google Scholar] [CrossRef]
  31. Bukhari, A.; Ijaz, I.; Gilani, E.; Nazir, A.; Zain, H.; Saeed, R.; Alarfaji, S.S.; Hussain, S.; Aftab, R.; Naseer, Y. Green Synthesis of Metal and Metal Oxide Nanoparticles Using Different Plants’ Parts for Antimicrobial Activity and Anticancer Activity: A Review Article. Coatings 2021, 11, 1374. [Google Scholar] [CrossRef]
  32. Yosri, N.; Khalifa, S.A.M.; Guo, Z.; Xu, B.; Zou, X.; El-Seedi, H.R. Marine Organisms: Pioneer Natural Sources of Polysaccharides/Proteins for Green Synthesis of Nanoparticles and Their Potential Applications. Int. J. Biol. Macromol. 2021, 193, 1767–1798. [Google Scholar] [CrossRef]
  33. Singh, T.A.; Sharma, A.; Tejwan, N.; Ghosh, N.; Das, J.; Sil, P.C. A State of the Art Review on the Synthesis, Antibacterial, Antioxidant, Antidiabetic and Tissue Regeneration Activities of Zinc Oxide Nanoparticles. Adv. Colloid Interface Sci. 2021, 295, 102495. [Google Scholar] [CrossRef]
  34. Hamrayev, H.; Shameli, K.; Yusefi, M.; Korpayev, S. Green Route for the Fabrication of ZnO Nanoparticles and Potential Functionalization with Chitosan Using Cross-Linkers: A Review. J. Res. Nanosci. Nanotechnol. 2021, 3, 1–25. [Google Scholar] [CrossRef]
  35. Kumar, J.A.; Krithiga, T.; Manigandan, S.; Sathish, S.; Renita, A.A.; Prakash, P.; Prasad, B.S.N.; Kumar, T.R.P.; Rajasimman, M.; Hosseini-Bandegharaei, A.; et al. A Focus to Green Synthesis of Metal/Metal Based Oxide Nanoparticles: Various Mechanisms and Applications towards Ecological Approach. J. Clean. Prod. 2021, 324, 129198. [Google Scholar] [CrossRef]
  36. Murali, M.; Kalegowda, N.; Gowtham, H.G.; Ansari, M.A.; Alomary, M.N.; Alghamdi, S.; Shilpa, N.; Singh, S.B.; Thriveni, M.C.; Aiyaz, M.; et al. Plant-Mediated Zinc Oxide Nanoparticles: Advances in the New Millennium towards Understanding Their Therapeutic Role in Biomedical Applications. Pharmaceutics 2021, 13, 1662. [Google Scholar] [CrossRef] [PubMed]
  37. Mallakpour, S.; Azadi, E.; Hussain, C.M. Recent Advancements in Synthesis and Drug Delivery Utilization of Polysaccharides-Based Nanocomposites: The Important Role of Nanoparticles and Layered Double Hydroxides. Int. J. Biol. Macromol. 2021, 193, 183–204. [Google Scholar] [CrossRef] [PubMed]
  38. Alrajhi, A.H.; Ahmed, N.M.; Al Shafouri, M.; Almessiere, M.A.; ahmed Mohammed Al-Ghamdi, A. Green Synthesis of Zinc Oxide Nanoparticles Using Salvia Officials Extract. Mater. Sci. Semicond. Process. 2021, 125, 105641. [Google Scholar] [CrossRef]
  39. Abomuti, M.A.; Danish, E.Y.; Firoz, A.; Hasan, N.; Malik, M.A. Green Synthesis of Zinc Oxide Nanoparticles Using Salvia Officinalis Leaf Extract and Their Photocatalytic and Antifungal Activities. Biology 2021, 10, 1075. [Google Scholar] [CrossRef]
  40. Ghorbani, A.; Esmaeilizadeh, M. Pharmacological Properties of Salvia Officinalis and Its Components. J. Tradit. Complement. Med. 2017, 7, 433–440. [Google Scholar] [CrossRef]
  41. Royji Albeladi, S.S.; Malik, M.A.; Al-thabaiti, S.A. Facile Biofabrication of Silver Nanoparticles Using Salvia Officinalis Leaf Extract and Its Catalytic Activity towards Congo Red Dye Degradation. J. Mater. Res. Technol. 2020, 9, 10031–10044. [Google Scholar] [CrossRef]
  42. Batool, M.; Khurshid, S.; Qureshi, Z.; Daoush, W.M. Adsorption, Antimicrobial and Wound Healing Activities of Biosynthesised Zinc Oxide Nanoparticles. Chem. Pap. 2021, 75, 893–907. [Google Scholar] [CrossRef]
  43. Primo, J.D.O.; Bittencourt, C.; Acosta, S.; Sierra-Castillo, A.; Colomer, J.-F.; Jaerger, S.; Teixeira, V.C.; Anaissi, F.J. Synthesis of Zinc Oxide Nanoparticles by Ecofriendly Routes: Adsorbent for Copper Removal from Wastewater. Front. Chem. 2020, 8, 571790. [Google Scholar] [CrossRef]
  44. Rasli, N.I.; Basri, H.; Harun, Z. Zinc Oxide from Aloe Vera Extract: Two-Level Factorial Screening of Biosynthesis Parameters. Heliyon 2020, 6, e03156. [Google Scholar] [CrossRef]
  45. Li, C.; Du, H.; Wang, L.; Shu, Q.; Zheng, Y.; Xu, Y.; Zhang, J.; Zhang, J.; Yang, R.; Ge, Y. Flavonoid Composition and Antioxidant Activity of Tree Peony (Paeonia Section Moutan) Yellow Flowers. J. Agric. Food Chem. 2009, 57, 8496–8503. [Google Scholar] [CrossRef] [PubMed]
  46. Nazaruk, J.; Jakoniuk, P. Flavonoid Composition and Antimicrobial Activity of Cirsium rivulare (Jacq.) All. Flowers. J. Ethnopharmacol. 2005, 102, 208–212. [Google Scholar] [CrossRef] [PubMed]
  47. Suručić, R.; Šmitran, A.; Gajić, D.; Božić, L.; Antić, M.; Topić-Vučenović, V.; Umičević, N.; Antunović, V.; Jelić, D. Phytosynthesis of Zinc Oxide Nanoparticles with Acetonic Extract of Flowers of Geranium robertianum L. (Geraniaceae). J. Hyg. Eng. Des. 2021, 34, 5. [Google Scholar]
  48. Ajayan, A.S.; Hebsur, N.B. Green Synthesis of Zinc Oxide Nanoparticles Using Tea (Camellia sinesis) and Datura (Datura stramonium) Leaf Extract and Their Characterization. Chem. Sci. Rev. Lett. 2021, 10, 150–157. [Google Scholar] [CrossRef]
  49. Surendra, B.S.; Mallikarjunaswamy, C.; Pramila, S.; Rekha, N.D. Bio-Mediated Synthesis of ZnO Nanoparticles Using Lantana Camara Flower Extract: Its Characterizations, Photocatalytic, Electrochemical and Anti-Inflammatory Applications. Environ. Nanotechnol. Monit. Manag. 2021, 15, 100442. [Google Scholar] [CrossRef]
  50. Golmohammadi, M.; Hassankiadeh, M.N.; Zhang, L. Facile Biosynthesis of SnO2/ZnO Nanocomposite Using Acroptilon Repens Flower Extract and Evaluation of Their Photocatalytic Activity. Ceram. Int. 2021, 47, 29303–29308. [Google Scholar] [CrossRef]
  51. Ilangovan, A.; Venkatramanan, A.; Thangarajan, P.; Saravanan, A.; Rajendran, S.; Kaveri, K. Green Synthesis of Zinc Oxide Nanoparticles (ZnO NPs) Using Aqueous Extract of Tagetes Erecta Flower and Evaluation of Its Antioxidant, Antimicrobial, and Cytotoxic Activities on HeLa Cell Line. Curr. Biotechnol. 2021, 10, 61–76. [Google Scholar] [CrossRef]
  52. Alotaibi, B.; Negm, W.A.; Elekhnawy, E.; El-Masry, T.A.; Elharty, M.E.; Saleh, A.; Abdelkader, D.H.; Mokhtar, F.A. Antibacterial Activity of Nano Zinc Oxide Green-Synthesised from Gardenia thailandica Triveng. Leaves against Pseudomonas aeruginosa Clinical Isolates: In Vitro and in Vivo Study. Artif. Cells Nanomed. Biotechnol. 2022, 50, 96–106. [Google Scholar] [CrossRef]
  53. Iqbal, T.; Raza, A.; Zafar, M.; Afsheen, S.; Kebaili, I.; Alrobei, H. Plant-Mediated Green Synthesis of Zinc Oxide Nanoparticles for Novel Application to Enhance the Shelf Life of Tomatoes. Appl. Nanosci. 2022, 12, 179–191. [Google Scholar] [CrossRef]
  54. Mane, P.; Shinde, B.; Mundada, P.; Karale, B.; Burungale, A. Biogenic Synthesis of ZnO Nanoparticles from Parthenium Histerophorus Extract and Its Catalytic Activity for Building Bioactive Polyhydroquinolines. Res. Chem. Intermed. 2021, 47, 1743–1758. [Google Scholar] [CrossRef]
  55. Parveen, K.; Kumar, N.; Ledwani, L. Green Synthesis of Zinc Oxide Nanoparticles Mediated from Cassia renigera Bark and Detect Its Effects on Four Varieties of Rice. ChemistrySelect 2022, 7, e202200415. [Google Scholar] [CrossRef]
  56. Hessien, M. Recent Progress in Zinc Oxide Nanomaterials and Nanocomposites: From Synthesis to Applications. Ceram. Int. 2022, 48, 22609–22628. [Google Scholar] [CrossRef]
  57. Fagier, M.A. Plant-Mediated Biosynthesis and Photocatalysis Activities of Zinc Oxide Nanoparticles: A Prospect towards Dyes Mineralization. J. Nanotechnol. 2021, 2021, e6629180. [Google Scholar] [CrossRef]
  58. Jadoun, S.; Arif, R.; Jangid, N.K.; Meena, R.K. Green Synthesis of Nanoparticles Using Plant Extracts: A Review. Environ. Chem. Lett. 2021, 19, 355–374. [Google Scholar] [CrossRef]
  59. Fawcett, D.; Verduin, J.J.; Shah, M.; Sharma, S.B.; Poinern, G.E.J. A Review of Current Research into the Biogenic Synthesis of Metal and Metal Oxide Nanoparticles via Marine Algae and Seagrasses. J. Nanosci. 2017, 2017, e8013850. [Google Scholar] [CrossRef]
  60. Salem, S.S.; Fouda, A. Green Synthesis of Metallic Nanoparticles and Their Prospective Biotechnological Applications: An Overview. Biol. Trace Elem. Res. 2021, 199, 344–370. [Google Scholar] [CrossRef]
  61. Berneira, L.M.; Poletti, T.; de Freitas, S.C.; Maron, G.K.; Carreno, N.L.V.; de Pereira, C.M.P. Novel Application of Sub-Antarctic Macroalgae as Zinc Oxide Nanoparticles Biosynthesizers. Mater. Lett. 2022, 320, 132341. [Google Scholar] [CrossRef]
  62. Kanniah, P.; Chelliah, P.; Thangapandi, J.R.; Thangapandi, E.J.J.S.B.; Kasi, M.; Sivasubramaniam, S. Benign Fabrication of Metallic/Metal Oxide Nanoparticles from Algae. In Agri-Waste and Microbes for Production of Sustainable Nanomaterials; Elsevier: Amsterdam, The Netherlands, 2022; pp. 465–493. [Google Scholar] [CrossRef]
  63. El-Said, G.F.; El-Sikaily, A. Chemical Composition of Some Seaweed from Mediterranean Sea Coast, Egypt. Environ. Monit. Assess. 2013, 185, 6089–6099. [Google Scholar] [CrossRef]
  64. Lin, S.-T.; Thirumavalavan, M.; Jiang, T.-Y.; Lee, J.-F. Synthesis of ZnO/Zn Nano Photocatalyst Using Modified Polysaccharides for Photodegradation of Dyes. Carbohydr. Polym. 2014, 105, 1–9. [Google Scholar] [CrossRef]
  65. Priyadharshini, R.I.; Prasannaraj, G.; Geetha, N.; Venkatachalam, P. Microwave-Mediated Extracellular Synthesis of Metallic Silver and Zinc Oxide Nanoparticles Using Macro-Algae (Gracilaria edulis) Extracts and Its Anticancer Activity against Human PC3 Cell Lines. Appl. Biochem. Biotechnol. 2014, 174, 2777–2790. [Google Scholar] [CrossRef]
  66. Alsaggaf, M.S.; Diab, A.M.; ElSaied, B.E.F.; Tayel, A.A.; Moussa, S.H. Application of ZnO Nanoparticles Phycosynthesized with Ulva fasciata Extract for Preserving Peeled Shrimp Quality. Nanomaterials 2021, 11, 385. [Google Scholar] [CrossRef] [PubMed]
  67. Anjali, K.P.; Sangeetha, B.M.; Raghunathan, R.; Devi, G.; Dutta, S. Seaweed Mediated Fabrication of Zinc Oxide Nanoparticles and Their Antibacterial, Antifungal and Anticancer Applications. ChemistrySelect 2021, 6, 647–656. [Google Scholar] [CrossRef]
  68. Thirumoorthy, G.S.; Balasubramaniam, O.; Kumaresan, P.; Muthusamy, P.; Subramani, K. Tetraselmis Indica Mediated Green Synthesis of Zinc Oxide (ZnO) Nanoparticles and Evaluating Its Antibacterial, Antioxidant, and Hemolytic Activity. BioNanoScience 2021, 11, 172–181. [Google Scholar] [CrossRef]
  69. Srivastava, S.; Bhargava, A. Biological Synthesis of Nanoparticles: Algae. In Green Nanoparticles: The Future of Nanobiotechnology; Srivastava, S., Bhargava, A., Eds.; Springer: Singapore, 2022; pp. 139–171. ISBN 9789811671067. [Google Scholar]
  70. Subramanian, H.; Krishnan, M.; Mahalingam, A. Photocatalytic Dye Degradation and Photoexcited Anti-Microbial Activities of Green Zinc Oxide Nanoparticles Synthesized via Sargassum Muticum Extracts. RSC Adv. 2022, 12, 985–997. [Google Scholar] [CrossRef]
  71. Azizi, S.; Ahmad, M.B.; Namvar, F.; Mohamad, R. Green Biosynthesis and Characterization of Zinc Oxide Nanoparticles Using Brown Marine Macroalga Sargassum Muticum Aqueous Extract. Mater. Lett. 2014, 116, 275–277. [Google Scholar] [CrossRef]
  72. Kumar, R.V.; Vinoth, S.; Baskar, V.; Arun, M.; Gurusaravanan, P. Synthesis of Zinc Oxide Nanoparticles Mediated by Dictyota dichotoma Endophytic Fungi and Its Photocatalytic Degradation of Fast Green Dye and Antibacterial Applications. S. Afr. J. Bot. 2022, in press. [CrossRef]
  73. Nagarajan, S.; Arumugam Kuppusamy, K. Extracellular Synthesis of Zinc Oxide Nanoparticle Using Seaweeds of Gulf of Mannar, India. J. Nanobiotechnol. 2013, 11, 39. [Google Scholar] [CrossRef]
  74. Elemike, E.E.; Ekennia, A.C.; Onwudiwe, D.C.; Ezeani, R.O. Chapter 8—Agro-Waste Materials: Sustainable Substrates in Nanotechnology. In Agri-Waste and Microbes for Production of Sustainable Nanomaterials; Abd-Elsalam, K.A., Periakaruppan, R., Rajeshkumar, S., Eds.; Nanobiotechnology for Plant Protection; Elsevier: Amsterdam, The Netherlands, 2022; pp. 187–214. ISBN 978-0-12-823575-1. [Google Scholar]
  75. Velázquez-Gamboa, M.C.; Rodríguez-Hernández, L.; Abud-Archila, M.; Gutiérrez-Miceli, F.A.; González-Mendoza, D.; Valdez-Salas, B.; González-Terreros, E.; Luján-Hidalgo, M.C. Agronomic Biofortification of Stevia rebaudiana with Zinc Oxide (ZnO) Phytonanoparticles and Antioxidant Compounds. Sugar Tech. 2021, 23, 453–460. [Google Scholar] [CrossRef]
  76. Anugrah, D.S.B.; Alexander, H.; Pramitasari, R.; Hudiyanti, D.; Sagita, C.P. A Review of Polysaccharide-Zinc Oxide Nanocomposites as Safe Coating for Fruits Preservation. Coatings 2020, 10, 988. [Google Scholar] [CrossRef]
  77. Zuorro, A.; Iannone, A.; Natali, S.; Lavecchia, R. Green Synthesis of Silver Nanoparticles Using Bilberry and Red Currant Waste Extracts. Processes 2019, 7, 193. [Google Scholar] [CrossRef]
  78. Dulta, K.; Koşarsoy Ağçeli, G.; Chauhan, P.; Jasrotia, R.; Chauhan, P.K. Ecofriendly Synthesis of Zinc Oxide Nanoparticles by Carica papaya Leaf Extract and Their Applications. J. Clust. Sci. 2021, 33, 603–617. [Google Scholar] [CrossRef]
  79. Abdelmigid, H.M.; Hussien, N.A.; Alyamani, A.A.; Morsi, M.M.; AlSufyani, N.M.; Kadi, H.A. Green Synthesis of Zinc Oxide Nanoparticles Using Pomegranate Fruit Peel and Solid Coffee Grounds vs. Chemical Method of Synthesis, with Their Biocompatibility and Antibacterial Properties Investigation. Molecules 2022, 27, 1236. [Google Scholar] [CrossRef] [PubMed]
  80. Lal, S.; Verma, R.; Chauhan, A.; Dhatwalia, J.; Guleria, I.; Ghotekar, S.; Thakur, S.; Mansi, K.; Kumar, R.; Kumari, A.; et al. Antioxidant, Antimicrobial, and Photocatalytic Activity of Green Synthesized ZnO-NPs from Myrica esculenta Fruits Extract. Inorg. Chem. Commun. 2022, 141, 109518. [Google Scholar] [CrossRef]
  81. Ramesh, R.; Parasaran, M.; Mubashira, G.T.F.; Flora, C.; Liakath Ali Khan, F.; Almaary, K.S.; Elbadawi, Y.B.; Chen, T.-W.; Kanimozhi, K.; Bashir, A.K.H.; et al. Biogenic Synthesis of ZnO and NiO Nanoparticles Mediated by Fermented Cocos nucifera. (L) Deoiled Cake Extract for Antimicrobial Applications towards Gram Positive and Gram Negative Pathogens. J. King Saud Univ.-Sci. 2022, 34, 101696. [Google Scholar] [CrossRef]
  82. Rambabu, K.; Bharath, G.; Banat, F.; Show, P.L. Green Synthesis of Zinc Oxide Nanoparticles Using Phoenix Dactylifera Waste as Bioreductant for Effective Dye Degradation and Antibacterial Performance in Wastewater Treatment. J. Hazard. Mater. 2021, 402, 123560. [Google Scholar] [CrossRef] [PubMed]
  83. Abbes, N.; Bekri, I.; Cheng, M.; Sejri, N.; Cheikhrouhou, M.; Xu, J. Green Synthesis and Characterization of Zinc Oxide Nanoparticles Using Mulberry Fruit and Their Antioxidant Activity. Mater. Sci. 2021, 28, 144–150. [Google Scholar] [CrossRef]
  84. Menazea, A.A.; Ismail, A.M.; Samy, A. Novel Green Synthesis of Zinc Oxide Nanoparticles Using Orange Waste and Its Thermal and Antibacterial Activity. J. Inorg. Organomet. Polym. 2021, 31, 4250–4259. [Google Scholar] [CrossRef]
  85. Thi, T.U.D.; Thoai Nguyen, T.; Dang Thi, Y.; Thi, K.H.T.; Thang Phan, B.; Ngoc Pham, K. Green Synthesis of ZnO Nanoparticles Using Orange Fruit Peel Extract for Antibacterial Activities. RSC Adv. 2020, 10, 23899–23907. [Google Scholar] [CrossRef]
  86. Proniewicza, E.; Tąta, A.; Starowicz, M.; Wójcik, A.; Pacek, J.; Molenda, M. Is the Electrochemical or the “Green Chemistry” Method the Optimal Method for the Synthesis of ZnO Nanoparticles for Applications to Biological Material? Characterization and SERS on ZnO. Colloids Surf. A Physicochem. Eng. Asp. 2021, 609, 125771. [Google Scholar] [CrossRef]
  87. Issam, N.; Naceur, D.; Nechi, G.; Maatalah, S.; Zribi, K.; Mhadhbi, H. Green Synthesised ZnO Nanoparticles Mediated by Olea europaea Leaf Extract and Their Antifungal Activity against Botrytis cinerea Infecting Faba Bean Plants. Arch. Phytopathol. Plant Prot. 2021, 54, 1083–1105. [Google Scholar] [CrossRef]
  88. Khan, M.I.; Fatima, N.; Shakil, M.; Tahir, M.B.; Riaz, K.N.; Rafique, M.; Iqbal, T.; Mahmood, K. Investigation of In-Vitro Antibacterial and Seed Germination Properties of Green Synthesized Pure and Nickel Doped ZnO Nanoparticles. Phys. B Condens. Matter 2021, 601, 412563. [Google Scholar] [CrossRef]
  89. Umamaheswari, A.; Prabu, S.L.; John, S.A.; Puratchikody, A. Green Synthesis of Zinc Oxide Nanoparticles Using Leaf Extracts of Raphanus sativus Var. Longipinnatus and Evaluation of Their Anticancer Property in A549 Cell Lines. Biotechnol. Rep. 2021, 29, e00595. [Google Scholar] [CrossRef] [PubMed]
  90. Djouadi, A.; Derouiche, S. Spinach Mediated Synthesis of Zinc Oxide Nanoparticles: Characterization, In Vitro Biological Activities Study and in Vivo Acute Toxicity Evaluation. Curr. Res. Green Sustain. Chem. 2021, 4, 100214. [Google Scholar] [CrossRef]
  91. Ahmad, M.; Rehman, W.; Khan, M.M.; Qureshi, M.T.; Gul, A.; Haq, S.; Ullah, R.; Rab, A.; Menaa, F. Phytogenic Fabrication of ZnO and Gold Decorated ZnO Nanoparticles for Photocatalytic Degradation of Rhodamine B. J. Environ. Chem. Eng. 2021, 9, 104725. [Google Scholar] [CrossRef]
  92. Saemi, R.; Taghavi, E.; Jafarizadeh-Malmiri, H.; Anarjan, N. Fabrication of Green ZnO Nanoparticles Using Walnut Leaf Extract to Develop an Antibacterial Film Based on Polyethylene–Starch–ZnO NPs. Green Process. Synth. 2021, 10, 112–124. [Google Scholar] [CrossRef]
  93. Kalia, A.; Kaur, M.; Shami, A.; Jawandha, S.K.; Alghuthaymi, M.A.; Thakur, A.; Abd-Elsalam, K.A. Nettle-Leaf Extract Derived ZnO/CuO Nanoparticle-Biopolymer-Based Antioxidant and Antimicrobial Nanocomposite Packaging Films and Their Impact on Extending the Post-Harvest Shelf Life of Guava Fruit. Biomolecules 2021, 11, 224. [Google Scholar] [CrossRef]
  94. Zahiri Oghani, F.; Tahvildari, K.; Nozari, M. Novel Antibacterial Food Packaging Based on Chitosan Loaded ZnO Nano Particles Prepared by Green Synthesis from Nettle Leaf Extract. J Inorg Organomet Polym 2021, 31, 43–54. [Google Scholar] [CrossRef]
  95. Negi, A.; Gangwar, R.; Vishwakarma, R.K.; Negi, D.S. Biogenic Zinc Oxide Nanoparticles as an Antibacterial, Antifungal, and Photocatalytic Tool Mediated via Leaves of Girardinia Diversifolia. Nanotechnol. Environ. Eng. 2022, 7, 223–233. [Google Scholar] [CrossRef]
  96. Zaheer, T.; Imran, M.; Pal, K.; Sajid, M.S.; Abbas, R.Z.; Aqib, A.I.; Hanif, M.A.; Khan, S.R.; Khan, M.K.; ur Rahman, S.; et al. Synthesis, Characterization and Acaricidal Activity of Green-Mediated ZnO Nanoparticles against Hyalomma Ticks. J. Mol. Struct. 2021, 1227, 129652. [Google Scholar] [CrossRef]
  97. Asmat-Campos, D.; Delfín-Narciso, D.; Juárez-Cortijo, L. Textiles Functionalized with ZnO Nanoparticles Obtained by Chemical and Green Synthesis Protocols: Evaluation of the Type of Textile and Resistance to UV Radiation. Fibers 2021, 9, 10. [Google Scholar] [CrossRef]
  98. Rashidian, G.; Lazado, C.C.; Mahboub, H.H.; Mohammadi-Aloucheh, R.; Prokić, M.D.; Nada, H.S.; Faggio, C. Chemically and Green Synthesized ZnO Nanoparticles Alter Key Immunological Molecules in Common Carp (Cyprinus carpio) Skin Mucus. Int. J. Mol. Sci. 2021, 22, 3270. [Google Scholar] [CrossRef] [PubMed]
  99. Iqbal, A.; Zakir, M.; Ali, M.M.; Irshad, S.; Javid, A.; Khan, M.; Ara, C.; Asmatullah. Effects of Allium cepa-Mediated Zinc Oxide Nanoparticles on Male Reproductive Tissue and Sperm Abnormalities of Albino Mice (Mus musculus). Appl. Nanosci. 2021, 11, 807–815. [Google Scholar] [CrossRef]
  100. Arab, C.; El Kurdi, R.; Patra, D. Chitosan Coated Zinc Curcumin Oxide Nanoparticles for the Determination of Ascorbic Acid. J. Mol. Liq. 2021, 328, 115504. [Google Scholar] [CrossRef]
  101. Manjula, R.; Prasad, B.D.; Vidya, Y.S.; Nagabhushana, H.; Anantharaju, K.S. Mentha Arvensis Mediated Synthesis and Characterization of Zinc Oxide Nanoparticles for Energy Applications. Mater. Today Proc. 2021, 46, 6051–6055. [Google Scholar] [CrossRef]
  102. Vijayakumar, S.; González-Sánchez, Z.I.; Malaikozhundan, B.; Saravanakumar, K.; Divya, M.; Vaseeharan, B.; Durán-Lara, E.F.; Wang, M.-H. Biogenic Synthesis of Rod Shaped ZnO Nanoparticles Using Red Paprika (Capsicum annuum L. Var. Grossum (L.) Sendt) and Their in Vitro Evaluation. J. Clust. Sci. 2021, 32, 1129–1139. [Google Scholar] [CrossRef]
  103. El Golli, A.; Fendrich, M.; Bazzanella, N.; Dridi, C.; Miotello, A.; Orlandi, M. Wastewater Remediation with ZnO Photocatalysts: Green Synthesis and Solar Concentration as an Economically and Environmentally Viable Route to Application. J. Environ. Manag. 2021, 286, 112226. [Google Scholar] [CrossRef]
  104. Mbenga, Y.; Mthiyane, M.N.; Botha, T.L.; Horn, S.; Pieters, R.; Wepener, V.; Onwudiwe, D.C. Nanoarchitectonics of ZnO Nanoparticles Mediated by Extract of Tulbaghia Violacea and Their Cytotoxicity Evaluation. J. Inorg. Organomet. Polym. 2022, 1–11. [Google Scholar] [CrossRef]
  105. Rajkumar, K.S.; Sivagaami, P.; Ramkumar, A.; Murugadas, A.; Srinivasan, V.; Arun, S.; Senthil Kumar, P.; Thirumurugan, R. Bio-Functionalized Zinc Oxide Nanoparticles: Potential Toxicity Impact on Freshwater Fish Cyprinus Carpio. Chemosphere 2022, 290, 133220. [Google Scholar] [CrossRef]
  106. Isah, S.; Ozbay, G. Valorization of Food Loss and Wastes: Feedstocks for Biofuels and Valuable Chemicals. Front. Sustain. Food Syst. 2020, 4, 82. [Google Scholar] [CrossRef]
  107. Ahmad, J.; Ovais, M.; Qasim, M. Chapter 4—Microbial Enzymes–Mediated Biosynthesis of Metal Nanoparticles. In Biogenic Nanoparticles for Cancer Theranostics; Patra, C., Ahmad, I., Ayaz, M., Khalil, A.T., Mukherjee, S., Ovais, M., Eds.; Micro and Nano Technologies; Elsevier: Amsterdam, The Netherlands, 2021; pp. 87–100. ISBN 978-0-12-821467-1. [Google Scholar]
  108. Piotrowska-Seget, Z.; Cycoń, M.; Kozdrój, J. Metal-Tolerant Bacteria Occurring in Heavily Polluted Soil and Mine Spoil. Appl. Soil Ecol. 2005, 28, 237–246. [Google Scholar] [CrossRef]
  109. Rehman, S.; Jermy, B.R.; Akhtar, S.; Borgio, J.F.; Azeez, S.A.; Ravinayagam, V.; Jindan, R.A.; Alsalem, Z.H.; Buhameid, A.; Gani, A. Isolation and Characterization of a Novel Thermophile; Bacillus haynesii, Applied for the Green Synthesis of ZnO Nanoparticles. Artif. Cells Nanomed. Biotechnol. 2019, 47, 2072–2082. [Google Scholar] [CrossRef] [PubMed]
  110. Siddique, K.; Shahid, M.; Shahzad, T.; Mahmood, F.; Nadeem, H.; Saif ur Rehman, M.; Hussain, S.; Sadak, O.; Gunasekaran, S.; Kamal, T.; et al. Comparative Efficacy of Biogenic Zinc Oxide Nanoparticles Synthesized by Pseudochrobactrum sp. C5 and Chemically Synthesized Zinc Oxide Nanoparticles for Catalytic Degradation of Dyes and Wastewater Treatment. Environ. Sci. Pollut. Res. 2021, 28, 28307–28318. [Google Scholar] [CrossRef] [PubMed]
  111. Ahmed, T.; Wu, Z.; Jiang, H.; Luo, J.; Noman, M.; Shahid, M.; Manzoor, I.; Allemailem, K.S.; Alrumaihi, F.; Li, B. Bioinspired Green Synthesis of Zinc Oxide Nanoparticles from a Native Bacillus cereus Strain RNT6: Characterization and Antibacterial Activity against Rice Panicle Blight Pathogens Burkholderia glumae and B. gladioli. Nanomaterials 2021, 11, 884. [Google Scholar] [CrossRef]
  112. Saleh, H.A.; Matter, I.A.; Abdel-Wareth, M.T.A.; Darwesh, O.M. Molluscicidal, Histopathological and Genotoxic Effects of Scenedesmus obliquus and Spirulina platensis Extracts and Their Biosynthesized Zinc Oxide Nanoparticles on Biomphalaria alexandrina Snails. Aquac. Res. 2022, 53, 3680–3695. [Google Scholar] [CrossRef]
  113. Faisal, S.; Abdullah; Rizwan, M.; Ullah, R.; Alotaibi, A.; Khattak, A.; Bibi, N.; Idrees, M. Paraclostridium Benzoelyticum Bacterium-Mediated Zinc Oxide Nanoparticles and Their In Vivo Multiple Biological Applications. Oxid. Med. Cell. Longev. 2022, 2022, e5994033. [Google Scholar] [CrossRef] [PubMed]
  114. Jeevanandam, J.; Kiew, S.F.; Ansah, S.B.; Lau, S.Y.; Barhoum, A.; Danquah, M.K.; Rodrigues, J. Green Approaches for the Synthesis of Metal and Metal Oxide Nanoparticles Using Microbial and Plant Extracts. Nanoscale 2022, 14, 2534–2571. [Google Scholar] [CrossRef]
  115. Jadoun, S.; Chauhan, N.P.S.; Zarrintaj, P.; Barani, M.; Varma, R.S. Nanomaterials for Sustainability: A Review on Green Synthesis of Nanoparticles Using Microorganisms. Environ. Chem. Lett. 2022; preprint. [Google Scholar]
  116. Mohd Yusof, H.; Mohamad, R.; Zaidan, U.H.; Abdul Rahman, N.A. Microbial Synthesis of Zinc Oxide Nanoparticles and Their Potential Application as an Antimicrobial Agent and a Feed Supplement in Animal Industry: A Review. J. Anim. Sci. Biotechnol. 2019, 10, 57. [Google Scholar] [CrossRef]
  117. Koul, B.; Poonia, A.K.; Yadav, D.; Jin, J.-O. Microbe-Mediated Biosynthesis of Nanoparticles: Applications and Future Prospects. Biomolecules 2021, 11, 886. [Google Scholar] [CrossRef]
  118. Golhani, D.K.; Khare, A.; Burra, G.K.; Jain, V.K.; Rao Mokka, J. Microbes Induced Biofabrication of Nanoparticles: A Review. Inorg. Nano-Met. Chem. 2020, 50, 983–999. [Google Scholar] [CrossRef]
  119. Ghosh, S.; Bhagwat, T.; Chopade, B.A.; Webster, T.J. Chapter 20—Patents, Technology Transfer, and Commercialization Aspects of Biogenic Nanoparticles. In Nanobiotechnology; Ghosh, S., Webster, T.J., Eds.; Elsevier: Amsterdam, The Netherlands, 2021; pp. 323–339. ISBN 978-0-12-822878-4. [Google Scholar]
  120. Yudasari, N.; Wiguna, P.A.; Handayani, W.; Suliyanti, M.M.; Imawan, C. The Formation and Antibacterial Activity of Zn/ZnO Nanoparticle Produced in Pometia pinnata Leaf Extract Solution Using a Laser Ablation Technique. Appl. Phys. A 2021, 127, 56. [Google Scholar] [CrossRef] [PubMed]
  121. Vinay, S.P.; Chandrasekhar, N. Structural and Biological Investigation of Green Synthesized Silver and Zinc Oxide Nanoparticles. J. Inorg. Organomet. Polym. 2021, 31, 552–558. [Google Scholar] [CrossRef]
  122. Soltanian, S.; Sheikhbahaei, M.; Mohamadi, N.; Pabarja, A.; Abadi, M.F.S.; Tahroudi, M.H.M. Biosynthesis of Zinc Oxide Nanoparticles Using Hertia Intermedia and Evaluation of Its Cytotoxic and Antimicrobial Activities. BioNanoScience 2021, 11, 245–255. [Google Scholar] [CrossRef]
  123. Şahin, B.; Soylu, S.; Kara, M.; Türkmen, M.; Aydin, R.; Çetin, H. Superior Antibacterial Activity against Seed-Borne Plant Bacterial Disease Agents and Enhanced Physical Properties of Novel Green Synthesized Nanostructured ZnO Using Thymbra spicata Plant Extract. Ceram. Int. 2021, 47, 341–350. [Google Scholar] [CrossRef]
  124. Rahman, A.; Harunsani, M.H.; Tan, A.L.; Ahmad, N.; Khan, M.M. Antioxidant and Antibacterial Studies of Phytogenic Fabricated ZnO Using Aqueous Leaf Extract of Ziziphus mauritiana Lam. Chem. Pap. 2021, 75, 3295–3308. [Google Scholar] [CrossRef]
  125. Pachaiappan, R.; Rajendran, S.; Ramalingam, G.; Vo, D.-V.N.; Priya, P.M.; Soto-Moscoso, M. Green Synthesis of Zinc Oxide Nanoparticles by Justicia adhatoda Leaves and Their Antimicrobial Activity. Chem. Eng. Technol. 2021, 44, 551–558. [Google Scholar] [CrossRef]
  126. Hasan, M.; Altaf, M.; Zafar, A.; Hassan, S.G.; Ali, Z.; Mustafa, G.; Munawar, T.; Saif, M.S.; Tariq, T.; Iqbal, F.; et al. Bioinspired Synthesis of Zinc Oxide Nano-Flowers: A Surface Enhanced Antibacterial and Harvesting Efficiency. Mater. Sci. Eng. C 2021, 119, 111280. [Google Scholar] [CrossRef]
  127. Ogunyemi, S.O.; Abdallah, Y.; Zhang, M.; Fouad, H.; Hong, X.; Ibrahim, E.; Masum, M.M.I.; Hossain, A.; Mo, J.; Li, B. Green Synthesis of Zinc Oxide Nanoparticles Using Different Plant Extracts and Their Antibacterial Activity against Xanthomonas oryzae Pv. Oryzae. Artif. Cells Nanomed. Biotechnol. 2019, 47, 341–352. [Google Scholar] [CrossRef]
  128. Álvarez-Chimal, R.; García-Pérez, V.I.; Álvarez-Pérez, M.A.; Arenas-Alatorre, J.Á. Green Synthesis of ZnO Nanoparticles Using a Dysphania ambrosioides Extract. Structural Characterization and Antibacterial Properties. Mater. Sci. Eng. C 2021, 118, 111540. [Google Scholar] [CrossRef]
  129. Gilavand, F.; Saki, R.; Mirzaei, S.Z.; Esmaeil Lashgarian, H.; Karkhane, M.; Marzban, A. Green Synthesis of Zinc Nanoparticles Using Aqueous Extract of Magnoliae Officinalis and Assessment of Its Bioactivity Potentials. Biointerface Res. Appl. Chem. 2020. [Google Scholar] [CrossRef]
  130. Kalaimurugan, D.; Lalitha, K.; Durairaj, K.; Sivasankar, P.; Park, S.; Nithya, K.; Shivakumar, M.S.; Liu, W.-C.; Balamuralikrishnan, B.; Venkatesan, S. Biogenic Synthesis of ZnO Nanoparticles Mediated from Borassus flabellifer (Linn): Antioxidant, Antimicrobial Activity against Clinical Pathogens, and Photocatalytic Degradation Activity with Molecular Modeling. Environ. Sci. Pollut. Res. 2022, 1–12. [Google Scholar] [CrossRef] [PubMed]
  131. Yadav, E.; Yadav, P. Biofabricated Zinc Oxide Nanoparticles Impair Cognitive Function via Modulating Oxidative Stress and Acetylcholinesterase Level in Mice. Environ. Toxicol. 2021, 36, 572–585. [Google Scholar] [CrossRef]
  132. Umavathi, S.; Mahboob, S.; Govindarajan, M.; Al-Ghanim, K.A.; Ahmed, Z.; Virik, P.; Al-Mulhm, N.; Subash, M.; Gopinath, K.; Kavitha, C. Green Synthesis of ZnO Nanoparticles for Antimicrobial and Vegetative Growth Applications: A Novel Approach for Advancing Efficient High Quality Health Care to Human Wellbeing. Saudi J. Biol. Sci. 2021, 28, 1808–1815. [Google Scholar] [CrossRef] [PubMed]
  133. Tang, Y.; Rajendran, P.; Veeraraghavan, V.P.; Hussain, S.; Balakrishna, J.P.; Chinnathambi, A.; Alharbi, S.A.; Alahmadi, T.A.; Rengarajan, T.; Mohan, S.K. Osteogenic Differentiation and Mineralization Potential of Zinc Oxide Nanoparticles from Scutellaria baicalensis on Human Osteoblast-like MG-63 Cells. Mater. Sci. Eng. C 2021, 119, 111656. [Google Scholar] [CrossRef] [PubMed]
  134. Sudha, K.G.; Ali, S.; Karunakaran, G.; Kowsalya, M.; Kolesnikov, E.; Gorshenkov, M.V.; Rajeshkumar, M.P. Cyrtrandroemia nicobarica-Synthesized ZnO NRs: A New Tool in Cancer Treatment. JOM 2021, 73, 364–372. [Google Scholar] [CrossRef]
  135. Seifipour, R.; Nozari, M.; Pishkar, L. Preparation of ZnO Nanoparticles Using Tragopogon collinus Leaf Extract and Study of Its Antibacterial Effects for Therapeutic Applications. J. Plant Biochem. Biotechnol. 2021, 30, 586–595. [Google Scholar] [CrossRef]
  136. Sathappan, S.; Kirubakaran, N.; Gunasekaran, D.; Gupta, P.K.; Verma, R.S.; Sundaram, J. Green Synthesis of Zinc Oxide Nanoparticles (ZnO NPs) Using Cissus quadrangularis: Characterization, Antimicrobial and Anticancer Studies. Proc. Natl. Acad. Sci. India Sect. B Biol. Sci. 2021, 91, 289–296. [Google Scholar] [CrossRef]
  137. Chinnathambi, A.; Alahmadi, T.A. Zinc Nanoparticles Green-Synthesized by Alhagi maurorum Leaf Aqueous Extract: Chemical Characterization and Cytotoxicity, Antioxidant, and Anti-Osteosarcoma Effects. Arab. J. Chem. 2021, 14, 103083. [Google Scholar] [CrossRef]
  138. Ali, S.; Sudha, K.G.; Karunakaran, G.; Kowsalya, M.; Kolesnikov, E.; Rajeshkumar, M.P. Green Synthesis of Stable Antioxidant, Anticancer and Photocatalytic Activity of Zinc Oxide Nanorods from Leea asiatica Leaf. J. Biotechnol. 2021, 329, 65–79. [Google Scholar] [CrossRef]
  139. El-Belely, E.F.; Farag, M.M.S.; Said, H.A.; Amin, A.S.; Azab, E.; Gobouri, A.A.; Fouda, A. Green Synthesis of Zinc Oxide Nanoparticles (ZnO-NPs) Using Arthrospira platensis (Class: Cyanophyceae) and Evaluation of Their Biomedical Activities. Nanomaterials 2021, 11, 95. [Google Scholar] [CrossRef]
  140. Dey, A.; Somaiah, S. Green Synthesis and Characterization of Zinc Oxide Nanoparticles Using Leaf Extract of Thryallis glauca (Cav.) Kuntze and Their Role as Antioxidant and Antibacterial. Microsc. Res. Tech. 2022, 2022, 2835–2847. [Google Scholar] [CrossRef] [PubMed]
  141. Abdullah, F.H.; Abu Bakar, N.H.H.; Abu Bakar, M. Comparative Study of Chemically Synthesized and Low Temperature Bio-Inspired Musa acuminata Peel Extract Mediated Zinc Oxide Nanoparticles for Enhanced Visible-Photocatalytic Degradation of Organic Contaminants in Wastewater Treatment. J. Hazard. Mater. 2021, 406, 124779. [Google Scholar] [CrossRef] [PubMed]
  142. Ekennia, A.C.; Uduagwu, D.N.; Nwaji, N.N.; Oje, O.O.; Emma-Uba, C.O.; Mgbii, S.I.; Olowo, O.J.; Nwanji, O.L. Green Synthesis of Biogenic Zinc Oxide Nanoflower as Dual Agent for Photodegradation of an Organic Dye and Tyrosinase Inhibitor. J. Inorg. Organomet. Polym. 2021, 31, 886–897. [Google Scholar] [CrossRef]
  143. Balanagireddy, G.; Narayana, A.; Roopa, M. Investigation of Organic Field-Effect Transistor (OFET) based NO2 Sensing Response using Low-Cost Green Synthesized Zinc Oxide Nanoparticles. Asian J. Chem. 2021, 33, 31–36. [Google Scholar] [CrossRef]
  144. Venkatesan, S.; Suresh, S.; Ramu, P.; Kandasamy, M.; Arumugam, J.; Thambidurai, S.; Prabu, K.M.; Pugazhenthiran, N. Biosynthesis of Zinc Oxide Nanoparticles Using Euphorbia milii Leaf Constituents: Characterization and Improved Photocatalytic Degradation of Methylene Blue Dye under Natural Sunlight. J. Indian Chem. Soc. 2022, 99, 100436. [Google Scholar] [CrossRef]
  145. Sportelli, M.C.; Izzi, M.; Kukushkina, E.A.; Hossain, S.I.; Picca, R.A.; Ditaranto, N.; Cioffi, N. Can Nanotechnology and Materials Science Help the Fight against SARS-CoV-2? Nanomaterials 2020, 10, 802. [Google Scholar] [CrossRef]
  146. Ghaffari, H.; Tavakoli, A.; Moradi, A.; Tabarraei, A.; Bokharaei-Salim, F.; Zahmatkeshan, M.; Farahmand, M.; Javanmard, D.; Kiani, S.J.; Esghaei, M.; et al. Inhibition of H1N1 Influenza Virus Infection by Zinc Oxide Nanoparticles: Another Emerging Application of Nanomedicine. J. Biomed. Sci. 2019, 26, 70. [Google Scholar] [CrossRef]
  147. El-Atab, N.; Mishra, R.B.; Hussain, M.M. Toward Nanotechnology-Enabled Face Masks against SARS-CoV-2 and Pandemic Respiratory Diseases. Nanotechnology 2021, 33, 062006. [Google Scholar] [CrossRef]
  148. Canalli Bortolassi, A.C.; Guerra, V.G.; Aguiar, M.L.; Soussan, L.; Cornu, D.; Miele, P.; Bechelany, M. Composites Based on Nanoparticle and Pan Electrospun Nanofiber Membranes for Air Filtration and Bacterial Removal. Nanomaterials 2019, 9, 1740. [Google Scholar] [CrossRef]
  149. Tiwari, A.K.; Mishra, A.; Pandey, G.; Gupta, M.K.; Pandey, P.C. Nanotechnology: A Potential Weapon to Fight against COVID-19. Part. Part. Syst. Charact. 2022, 39, 2100159. [Google Scholar] [CrossRef]
  150. Kampf, G. Potential Role of Inanimate Surfaces for the Spread of Coronaviruses and Their Inactivation with Disinfectant Agents. Infect. Prev. Pract. 2020, 2, 100044. [Google Scholar] [CrossRef] [PubMed]
  151. Imani, S.M.; Ladouceur, L.; Marshall, T.; Maclachlan, R.; Soleymani, L.; Didar, T.F. Antimicrobial Nanomaterials and Coatings: Current Mechanisms and Future Perspectives to Control the Spread of Viruses Including SARS-CoV-2. ACS Nano 2020, 14, 12341–12369. [Google Scholar] [CrossRef]
  152. Shirvanimoghaddam, K.; Akbari, M.K.; Yadav, R.; Al-Tamimi, A.K.; Naebe, M. Fight against COVID-19: The Case of Antiviral Surfaces. APL Mater. 2021, 9, 031112. [Google Scholar] [CrossRef] [PubMed]
  153. Jiang, S.; Lin, K.; Cai, M. ZnO Nanomaterials: Current Advancements in Antibacterial Mechanisms and Applications. Front. Chem. 2020, 8, 580. [Google Scholar] [CrossRef] [PubMed]
  154. Li, J.; Sang, H.; Guo, H.; Popko, J.T.; He, L.; White, J.C.; Dhankher, O.P.; Jung, G.; Xing, B. Antifungal Mechanisms of ZnO and Ag Nanoparticles ToSclerotinia homoeocarpa. Nanotechnology 2017, 28, 155101. [Google Scholar] [CrossRef]
  155. Gutiérrez Rodelo, C.; Salinas, R.A.; Armenta Jaime, E.; Armenta, S.; Galdámez-Martínez, A.; Castillo-Blum, S.E.; Astudillo-de la Vega, H.; Nirmala Grace, A.; Aguilar-Salinas, C.A.; Gutiérrez Rodelo, J.; et al. Zinc Associated Nanomaterials and Their Intervention in Emerging Respiratory Viruses: Journey to the Field of Biomedicine and Biomaterials. Coord. Chem. Rev. 2022, 457, 214402. [Google Scholar] [CrossRef]
  156. Melk, M.M.; El-Hawary, S.S.; Melek, F.R.; Saleh, D.O.; Ali, O.M.; Raey, M.A.E.; Selim, N.M. Antiviral Activity of Zinc Oxide Nanoparticles Mediated by Plumbago indica L. Extract Against Herpes Simplex Virus Type 1 (HSV-1). Int. J. Nanomed. 2021, 16, 8221–8233. [Google Scholar] [CrossRef]
  157. Attia, G.H.; Moemen, Y.S.; Youns, M.; Ibrahim, A.M.; Abdou, R.; El Raey, M.A. Antiviral Zinc Oxide Nanoparticles Mediated by Hesperidin and in Silico Comparison Study between Antiviral Phenolics as Anti-SARS-CoV-2. Colloids Surf. B Biointerfaces 2021, 203, 111724. [Google Scholar] [CrossRef]
  158. Hamdi, M.; Abdel-Bar, H.M.; Elmowafy, E.; El-khouly, A.; Mansour, M.; Awad, G.A.S. Investigating the Internalization and COVID-19 Antiviral Computational Analysis of Optimized Nanoscale Zinc Oxide. ACS Omega 2021, 6, 6848–6860. [Google Scholar] [CrossRef]
  159. Sportelli, M.C.; Izzi, M.; Loconsole, D.; Sallustio, A.; Picca, R.A.; Felici, R.; Chironna, M.; Cioffi, N. On the Efficacy of ZnO Nanostructures against SARS-CoV-2. Int. J. Mol. Sci. 2022, 23, 3040. [Google Scholar] [CrossRef]
  160. Gonzalez, A.; Aboubakr, H.A.; Brockgreitens, J.; Hao, W.; Wang, Y.; Goyal, S.M.; Abbas, A. Durable Nanocomposite Face Masks with High Particulate Filtration and Rapid Inactivation of Coronaviruses. Sci. Rep. 2021, 11, 24318. [Google Scholar] [CrossRef] [PubMed]
  161. Merkl, P.; Long, S.; McInerney, G.M.; Sotiriou, G.A. Antiviral Activity of Silver, Copper Oxide and Zinc Oxide Nanoparticle Coatings against SARS-CoV-2. Nanomaterials 2021, 11, 1312. [Google Scholar] [CrossRef] [PubMed]
  162. El-Megharbel, S.M.; Alsawat, M.; Al-Salmi, F.A.; Hamza, R.Z. Utilizing of (Zinc Oxide Nano-Spray) for Disinfection against “SARS-CoV-2” and Testing Its Biological Effectiveness on Some Biochemical Parameters during (COVID-19 Pandemic)—“ZnO Nanoparticles Have Antiviral Activity against (SARS-CoV-2)”. Coatings 2021, 11, 388. [Google Scholar] [CrossRef]
  163. Ghareeb, D.A.; Saleh, S.R.; Seadawy, M.G.; Nofal, M.S.; Abdulmalek, S.A.; Hassan, S.F.; Khedr, S.M.; AbdElwahab, M.G.; Sobhy, A.A.; Abdel-Hamid, A.S.A.; et al. Nanoparticles of ZnO/Berberine Complex Contract COVID-19 and Respiratory Co-Bacterial Infection in Addition to Elimination of Hydroxychloroquine Toxicity. J. Pharm. Investig. 2021, 51, 735–757. [Google Scholar] [CrossRef]
  164. Ishida, T. Anti-Viral Vaccine Activity of Zinc(Ⅱ) for Viral Prevention, Entry, Replication, and Spreading During Pathogenesis Process. CTBEB 2019, 19, 556012. [Google Scholar] [CrossRef]
  165. Mizielińska, M.; Nawrotek, P.; Stachurska, X.; Ordon, M.; Bartkowiak, A. Packaging Covered with Antiviral and Antibacterial Coatings Based on ZnO Nanoparticles Supplemented with Geraniol and Carvacrol. Int. J. Mol. Sci. 2021, 22, 1717. [Google Scholar] [CrossRef]
Figure 1. Number of papers published about the biosynthesis of ZnONPs in the last years. Data analysis performed on Scopus® using “Biosynthesis”, “Zinc oxide” and “Nanoparticles” as keywords.
Figure 1. Number of papers published about the biosynthesis of ZnONPs in the last years. Data analysis performed on Scopus® using “Biosynthesis”, “Zinc oxide” and “Nanoparticles” as keywords.
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Figure 2. Most used source for reactants exploited in the biogenic synthesis of ZnONPs.
Figure 2. Most used source for reactants exploited in the biogenic synthesis of ZnONPs.
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Figure 3. Schematic explanation of the phyto-mediated synthesis of ZnONPs. (1) washing, (2) grinding-milling, (3) filtration, (4) pre-concentration (facultative), (5,6) addition of zinc precursor and ZnONPs production. Wiley material reproduced from [15] with permission from John Wiley & Sons Inc, the Wiley Companies®.
Figure 3. Schematic explanation of the phyto-mediated synthesis of ZnONPs. (1) washing, (2) grinding-milling, (3) filtration, (4) pre-concentration (facultative), (5,6) addition of zinc precursor and ZnONPs production. Wiley material reproduced from [15] with permission from John Wiley & Sons Inc, the Wiley Companies®.
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Figure 4. Synthesis route and characterization of algae-based metal and metal oxide NPs. Reprinted from [62] with permission from Elsevier.
Figure 4. Synthesis route and characterization of algae-based metal and metal oxide NPs. Reprinted from [62] with permission from Elsevier.
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Figure 5. FESEM (field emission scanning electron microscopy) images of ZnO synthesized using garlic bulb extracts. Reprinted from [103] with permission from Elsevier.
Figure 5. FESEM (field emission scanning electron microscopy) images of ZnO synthesized using garlic bulb extracts. Reprinted from [103] with permission from Elsevier.
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Figure 6. Role of NADH and NADH-dependent microbial enzymes in the synthesis of ZnONPs. Adapted from [107] with permission from Elsevier.
Figure 6. Role of NADH and NADH-dependent microbial enzymes in the synthesis of ZnONPs. Adapted from [107] with permission from Elsevier.
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Figure 7. Possible mechanisms of antiviral activity of ZnO against SARS-CoV-2. (a) Design of ZnO nanostructures for the possible anchoring of SARS-CoV-2 virions, thus inhibiting interactions with host cell receptors. (b) Internalization of ZnO nanostructures for the inhibition of early stages of the viral replication cycle. (c) Ion release as a surface attack mechanism to disrupt the plasmid and RNA virus integrity. (d) Photocatalytic generation of reactive oxygen species for the possible degradation of the lipid, protein, and nucleic structure of SARS-CoV-2. Reproduced from [155]; article distributed under the terms of the Creative Commons CC-BY license.
Figure 7. Possible mechanisms of antiviral activity of ZnO against SARS-CoV-2. (a) Design of ZnO nanostructures for the possible anchoring of SARS-CoV-2 virions, thus inhibiting interactions with host cell receptors. (b) Internalization of ZnO nanostructures for the inhibition of early stages of the viral replication cycle. (c) Ion release as a surface attack mechanism to disrupt the plasmid and RNA virus integrity. (d) Photocatalytic generation of reactive oxygen species for the possible degradation of the lipid, protein, and nucleic structure of SARS-CoV-2. Reproduced from [155]; article distributed under the terms of the Creative Commons CC-BY license.
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MDPI and ACS Style

Sportelli, M.C.; Gaudiuso, C.; Volpe, A.; Izzi, M.; Picca, R.A.; Ancona, A.; Cioffi, N. Biogenic Synthesis of ZnO Nanoparticles and Their Application as Bioactive Agents: A Critical Overview. Reactions 2022, 3, 423-441.

AMA Style

Sportelli MC, Gaudiuso C, Volpe A, Izzi M, Picca RA, Ancona A, Cioffi N. Biogenic Synthesis of ZnO Nanoparticles and Their Application as Bioactive Agents: A Critical Overview. Reactions. 2022; 3(3):423-441.

Chicago/Turabian Style

Sportelli, Maria Chiara, Caterina Gaudiuso, Annalisa Volpe, Margherita Izzi, Rosaria Anna Picca, Antonio Ancona, and Nicola Cioffi. 2022. "Biogenic Synthesis of ZnO Nanoparticles and Their Application as Bioactive Agents: A Critical Overview" Reactions 3, no. 3: 423-441.

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