Next Issue
Volume 5, December
Previous Issue
Volume 5, June
 
 

Chemistry, Volume 5, Issue 3 (September 2023) – 39 articles

Cover Story (view full-size image): Metal detection is important for evaluating metal-related health and diseases and for managing metal-based drug treatments. While DNAzyme-based catalytic beacons have emerged as a powerful class of sensors that can be generalized to detect almost any metal ion with high sensitivity and selectivity, the requirement of laser excitation that causes photobleaching has limited its applications for on-site and real-time detection. To overcome this limitation, Lu and Zhang and colleagues report DNAzyme biosensors that use bioluminescence resonance energy transfer between a luciferase and Cy3 fluorophores for the ratiometric sensing of metal ions. The sensors allow the detection of Zn2+ in serum samples using a smartphone camera. View this paper
  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Reader to open them.
Order results
Result details
Section
Select all
Export citation of selected articles as:
18 pages, 3075 KiB  
Article
In Pursuit of Next Generation N-Heterocyclic Carbene-Stabilized Copper and Silver Precursors for Metalorganic Chemical Vapor Deposition and Atomic Layer Deposition Processes
by Ilamparithy Selvakumar, Nils Boysen, Marco Bürger and Anjana Devi
Chemistry 2023, 5(3), 2038-2055; https://doi.org/10.3390/chemistry5030138 - 20 Sep 2023
Viewed by 1346
Abstract
Volatile, reactive, and thermally stable organometallic copper and silver complexes are of significant interest as precursors for the metalorganic chemical vapor deposition (MOCVD) and atomic layer deposition (ALD) of ultra-thin metallic films. Well-established CuI and AgI precursors are commonly stabilized by [...] Read more.
Volatile, reactive, and thermally stable organometallic copper and silver complexes are of significant interest as precursors for the metalorganic chemical vapor deposition (MOCVD) and atomic layer deposition (ALD) of ultra-thin metallic films. Well-established CuI and AgI precursors are commonly stabilized by halogens, phosphorous, silicon, and oxygen, potentially leading to the incorporation of these elements as impurities in the thin films. These precursors are typically stabilized by a neutral and anionic ligand. Recent advancements were established by the stabilization of these complexes using N-heterocyclic carbenes (NHCs) as neutral ligands. To further enhance the reactivity, in this study the anionic ligand is sequentially changed from β-diketonates to β-ketoiminates and β-diketiminates, yielding two new CuI and two new AgI NHC-stabilized complexes in the general form of [M(NHC) (R)] (M = Cu, Ag; R = β-ketoiminate, β-diketiminate). The synthesized complexes were comparatively analyzed in solid, dissolved, and gaseous states. Furthermore, the thermal properties were investigated to assess their potential application in MOCVD or ALD. Among the newly synthesized complexes, the β-diketiminate-based [Cu(tBuNHC) (NacNacMe)] was identified to be the most suitable candidate as a precursor for Cu thin film deposition. The resulting halogen-, oxygen-, and silicon-free CuI and AgI precursors for MOCVD and ALD applications are established for the first time and set a new baseline for coinage metal precursors. Full article
(This article belongs to the Special Issue Commemorating 150 Years of Justus von Liebig’s Legacy)
Show Figures

Figure 1

13 pages, 3397 KiB  
Article
High Thermal Stability of Enzyme-MOF Composites at 180 °C
by Shitong Cui and Jun Ge
Chemistry 2023, 5(3), 2025-2037; https://doi.org/10.3390/chemistry5030137 - 19 Sep 2023
Cited by 1 | Viewed by 1242
Abstract
Encapsulating enzymes in a tailored scaffold is of great potential in industrial enzymatic catalysis, which can enhance the stability of enzymes thus expanding their applications. Metal–organic frameworks (MOFs) are emerging as promising candidates for enzyme encapsulation due to their precise pore structure, ease [...] Read more.
Encapsulating enzymes in a tailored scaffold is of great potential in industrial enzymatic catalysis, which can enhance the stability of enzymes thus expanding their applications. Metal–organic frameworks (MOFs) are emerging as promising candidates for enzyme encapsulation due to their precise pore structure, ease of synthesis and good biocompatibility. Despite the fact that enzymes encapsulated in MOFs can obtain enhanced stability, there has been little discussion about the thermal stability of enzyme-MOF composites in solid state under extremely high temperatures. Herein, we fabricated the enzyme-MOF composites, CALB-ZIF-8, via a convenient coprecipitation method in aqueous solution, which exhibited good thermal stability at 180 °C. It was found that the activity of CALB encapsulated in ZIF-8 retained nearly ~80% after heating for 10 min at 180 °C. A finite element method was applied to investigate the heat transfer process within a ZIF-8 model, indicating that the air filled in cavities of ZIF-8 played a significant role in hindering the heat transfer and this may be an important reason for the outstanding thermal stability of CALB-ZIF-8 at 180 °C, which paves a new path for expanding the industrial application of enzyme-MOF composites. Full article
Show Figures

Figure 1

16 pages, 1824 KiB  
Article
The Antimicrobial and Mosquitocidal Activity of Green Magnesium Oxide Nanoparticles Synthesized by an Aqueous Peel Extract of Punica granatum
by Amr Fouda, Khalid S. Alshallash, Mohammed I. Alghonaim, Ahmed M. Eid, Ahmed M. Alemam, Mohamed A. Awad and Mohammed F. Hamza
Chemistry 2023, 5(3), 2009-2024; https://doi.org/10.3390/chemistry5030136 - 12 Sep 2023
Cited by 2 | Viewed by 1405
Abstract
An aqueous extract of Punica granatum peel was used as a biocatalyst for magnesium oxide nanoparticle (MgO-NP) synthesis, which was characterized via UV-Vis spectroscopy, TEM, EDX, FT-IR, XRD, DLS, and zeta potential. Data showed the efficacy of the plant aqueous extract in forming [...] Read more.
An aqueous extract of Punica granatum peel was used as a biocatalyst for magnesium oxide nanoparticle (MgO-NP) synthesis, which was characterized via UV-Vis spectroscopy, TEM, EDX, FT-IR, XRD, DLS, and zeta potential. Data showed the efficacy of the plant aqueous extract in forming spherical, crystalline-nature, well-arranged MgO-NPs with sizes in the range of 10–45 nm with average sizes of 24.82 ± 8.85 nm. Moreover, EDX analysis revealed that the highest weight and atomic percentages were recorded for Mg and O ions. The green synthesized MgO-NPs showed antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, E. coli, Pseudomonas aeruginosa, and Candida albicans in a concentration-dependent manner with clear zones in the range of 8.7 ± 0.6 to 19.7 ± 0.5 mm with various concentrations. Also, the MIC value was varied to be 25 µg mL−1 for Gram-negative bacteria, B. subtilis, and C. albicans and 50 µg mL−1 for S. aureus. Moreover, MgO-NPs showed high activity against the 3rd-instar larvae of Culex quinquefasciatus. The mortality percentages were concentration- and time-dependent. Data analysis showed that the highest mortality was 88.3 ± 3.2%, attained at a concentration of 100 µg mL−1 after 72 h. Also, all originated pupae were malformed and did not hatch to adults, with mortality percentages of 100% at all concentrations. Overall, the P. granatum-mediated MgO-NPs showed promising activity in inhibiting the growth of pathogenic microbes and the hatching of C. quinquefasciatus larvae to adults. Full article
(This article belongs to the Special Issue Recent Advances in Antimicrobial Materials)
Show Figures

Figure 1

11 pages, 1767 KiB  
Article
Expanding Heteroaromatic and 2-Aminosugar Chemical Space Accessible from the Biopolymer Chitin
by Thaís A. Rossa, Jessica C. Neville, Seongmin Paul Jun, Tilo Söhnel and Jonathan Sperry
Chemistry 2023, 5(3), 1998-2008; https://doi.org/10.3390/chemistry5030135 - 09 Sep 2023
Viewed by 985
Abstract
Herein, we report the expansion of chemical space available from chitin, accessible via the biogenic N-platforms 3A5AF, M4A2C, and di-HAF. The biologically active heteroaromatics furo[3,2-d]pyrimidin-4-one and furo[3,2-d]pyrimidin-4-amine can be selectively accessed from 3A5AF and M4A2C, respectively. The chiral [...] Read more.
Herein, we report the expansion of chemical space available from chitin, accessible via the biogenic N-platforms 3A5AF, M4A2C, and di-HAF. The biologically active heteroaromatics furo[3,2-d]pyrimidin-4-one and furo[3,2-d]pyrimidin-4-amine can be selectively accessed from 3A5AF and M4A2C, respectively. The chiral pool synthon di-HAF is a viable substrate for Achmatowicz rearrangement, providing streamlined access to 2-aminosugars possessing a versatile hydroxymethyl group at C5. Full article
(This article belongs to the Special Issue Green Chemistry—a Themed Issue in Honor of Professor James Clark)
Show Figures

Graphical abstract

8 pages, 3708 KiB  
Communication
Solid State Fabrication of Copper Nanoclusters and Supraparticles
by Rui Wang, Yunyun Zheng and Yunsheng Xia
Chemistry 2023, 5(3), 1990-1997; https://doi.org/10.3390/chemistry5030134 - 06 Sep 2023
Viewed by 1034
Abstract
In this study, we present solid state processes for the fabrication of copper nanoclusters (NCs) and hierarchical supraparticles (SPs). To achieve this, copper salt and thiols are mixed and are then grinded for 10–15 min, and the nano-products are thereby obtained. Interestingly, it [...] Read more.
In this study, we present solid state processes for the fabrication of copper nanoclusters (NCs) and hierarchical supraparticles (SPs). To achieve this, copper salt and thiols are mixed and are then grinded for 10–15 min, and the nano-products are thereby obtained. Interestingly, it was found in this study that the formation of the NCs or SPs is completely dependent on the grinding methods that are used: with mechanical grinding, the products are several nanometer-sized NCs, whereas manual grinding in an agate mortar can obtain Cu SPs with diameters as low as 10 nm all the way up to 200 nm. The photoluminescence emission wavelength of the nano-products is located at ~680 nm. The Stokes shift of the obtained nanomaterials is more than 300 nm. The emission quantum yields of the Cu NCs and SPs are as high as 47.5% and 63%, respectively. Due to their facile fabrication processes and their favorable optical properties, the two as-prepared types of copper nano-materials exhibit great potential for bio-imaging and bio-sensing applications. Full article
Show Figures

Figure 1

29 pages, 5231 KiB  
Article
Syntheses, Crystal and Electronic Structures of Rhodium and Iridium Pyridine Di-Imine Complexes with O- and S-Donor Ligands: (Hydroxido, Methoxido and Thiolato)
by Michel Stephan, Max Völker, Matthias Schreyer and Peter Burger
Chemistry 2023, 5(3), 1961-1989; https://doi.org/10.3390/chemistry5030133 - 05 Sep 2023
Viewed by 1307
Abstract
The syntheses of new neutral square-planar pyridine di-imine rhodium and iridium complexes with O- and S-donor (OH, OR, SH, SMe and SPh) ligands along with analogous cationic compounds are reported. Their crystal and electronic structures are investigated in detail with a focus on [...] Read more.
The syntheses of new neutral square-planar pyridine di-imine rhodium and iridium complexes with O- and S-donor (OH, OR, SH, SMe and SPh) ligands along with analogous cationic compounds are reported. Their crystal and electronic structures are investigated in detail with a focus on the non-innocence/innocence of the PDI ligand. The oxidation states of the metal centers were analyzed by a variety of experimental (XPS and XAS) and theoretical (LOBA, EOS and OSLO) methods. The dπ-pπ interaction between the metal centers and the π-donor ligands was investigated by theoretical methods and revealed the partial multiple-bond character of the M-O,S bonds. Experimental support is provided by a sizable barrier for the rotation about the Ir-S bond in the methyl thiolato complex and confirmed by DFT and LNO-CCSD(T) calculations. This was corroborated by the high Ir-O and Ir-S bond dissociation enthalpies calculated at the PNO-CCSD(T) level. Full article
(This article belongs to the Special Issue Commemorating 150 Years of Justus von Liebig’s Legacy)
Show Figures

Graphical abstract

19 pages, 4837 KiB  
Article
Encapsulation of Ciprofloxacin into a Cyclodextrin Polymer Matrix: The Complex Formation with Human Serum Albumin and In Vitro Studies
by Anna A. Skuredina, Tatiana Yu. Kopnova, Natalya G. Belogurova and Elena V. Kudryashova
Chemistry 2023, 5(3), 1942-1960; https://doi.org/10.3390/chemistry5030132 - 01 Sep 2023
Cited by 1 | Viewed by 1194
Abstract
Here, we propose a drug delivery system for ciprofloxacin (CF) based on cyclodextrin (CD) polymer. We obtained a 3D matrix system with encapsulated drug molecules by crosslinking CF+CD non-covalent complexes with 1.6-hexamethylene isocyanate. The obtained polycarbamide (MAX-system) represents particles (~225 nm in diameter) [...] Read more.
Here, we propose a drug delivery system for ciprofloxacin (CF) based on cyclodextrin (CD) polymer. We obtained a 3D matrix system with encapsulated drug molecules by crosslinking CF+CD non-covalent complexes with 1.6-hexamethylene isocyanate. The obtained polycarbamide (MAX-system) represents particles (~225 nm in diameter) that demonstrate CF’s sustained release. We investigated how the carrier affects the drug’s interaction with the biological macromolecule human serum albumin (HSA) and CF’s antibacterial properties. Compared to a binary CF–HSA system, CD decreases CF’s binding efficiency to HSA by two times, whereas CF encapsulation in a polymer matrix doubles the Ka value and prevents protein aggregation. The changes in HSA’s secondary structure indicate no alterations in the main mechanism of complex formation between CF and HSA in the presence of both CD-based carriers. CD as well as MAX systems practically do not change CF’s activity against E. coli and B. subtilis, but for MAX systems, prolonged action is realized due to CF’s sustained release. We believe that our findings are important for the further development of new, efficient drug forms. Full article
(This article belongs to the Section Medicinal Chemistry)
Show Figures

Figure 1

21 pages, 1382 KiB  
Review
Antioxidant Determining Using Electrochemical Method
by Rani Melati Sukma, Dyah Iswantini, Novik Nurhidayat, Mohamad Rafi and Dita Ariyanti
Chemistry 2023, 5(3), 1921-1941; https://doi.org/10.3390/chemistry5030131 - 01 Sep 2023
Cited by 1 | Viewed by 1879
Abstract
Antioxidants are very beneficial for health as they protect the body from the effects of free radicals on various degenerative diseases caused by food contamination, air pollution, sunlight, etc. In general, methods for measuring the capacity of antioxidants generally use accurate methods such [...] Read more.
Antioxidants are very beneficial for health as they protect the body from the effects of free radicals on various degenerative diseases caused by food contamination, air pollution, sunlight, etc. In general, methods for measuring the capacity of antioxidants generally use accurate methods such as spectrophotometry and chromatography. Still, this takes time, accurate sample preparation, and must be performed in a laboratory with particular expertise. Therefore, a new, more practical method needs to be developed for determining antioxidants, namely the electrochemical method. The electrochemical method is a promising method to develop because it comes with several advantages, including high sensitivity and fast response. The electrochemical method discussed in this article reviews sensors, biosensors, and nanosensors. This paper comprehensively analyzes contemporary developments in electrochemical biosensor techniques and antioxidant evaluation methodologies. The discussion centers on utilizing multiple biosensors. Electrochemical biosensors have been determined to be prevalent in analyzing food quality, assessing active factor functionality, and screening practical components. The present study outlines the difficulties linked with electrochemical bio-sensor technology and provides insights into the potential avenues for future research in this domain. Full article
(This article belongs to the Section Electrochemistry and Photoredox Processes)
Show Figures

Graphical abstract

10 pages, 1533 KiB  
Communication
Structure, Stability and Binding Properties of Collagen-Binding Domains from Streptococcus mutans
by Akari Nishi, Hikaru Matsui, Azumi Hirata, Atsushi Mukaiyama, Shun-ichi Tanaka, Takuya Yoshizawa, Hiroyoshi Matsumura, Ryota Nomura, Kazuhiko Nakano and Kazufumi Takano
Chemistry 2023, 5(3), 1911-1920; https://doi.org/10.3390/chemistry5030130 - 01 Sep 2023
Cited by 1 | Viewed by 1101
Abstract
Collagen-binding proteins (CBP), Cnm and Cbm, from Streptococcus mutans are involved in infective endocarditis caused by S. mutans because of their collagen-binding ability. In this study, we focused on the collagen-binding domain (CBD), which is responsible for the collagen-binding ability of CBP, and [...] Read more.
Collagen-binding proteins (CBP), Cnm and Cbm, from Streptococcus mutans are involved in infective endocarditis caused by S. mutans because of their collagen-binding ability. In this study, we focused on the collagen-binding domain (CBD), which is responsible for the collagen-binding ability of CBP, and analyzed its structure, binding activity, and stability using CBD domain variants. The CBD consists of the N1 domain, linker, N2 domain, and latch (N1-N2~) as predicted from the amino acid sequences. The crystal structure of the Cnm/CBD was determined at a 1.81 Å resolution. N1_linker_N2 forms a ring structure that can enfold collagen molecules, and the latch interacts with N1 to form a ring clasp. N1 and N2 have similar immunoglobulin folds. The collagen-binding activities of Cbm/CBD and its domain variants were examined using ELISA. N1-N2~ bound to collagen with KD = 2.8 μM, and the latch-deleted variant (N1-N2) showed weaker binding (KD = 28 μM). The linker-deleted variant (N1N2~) and single-domain variants (N1 and N2) showed no binding activity, whereas the domain-swapped variant (N2-N1~) showed binding ability, indicating that the two N-domains and the linker are important for collagen binding. Thermal denaturation experiments showed that N1-N2 was slightly less stable than N1-N2~, and that N2 was more stable than N1. The results of this study provide a basis for the development of CBD inhibitors and applied research utilizing their collagen-binding ability. Full article
(This article belongs to the Section Crystallography)
Show Figures

Figure 1

29 pages, 10492 KiB  
Review
Self-Assembled DNA Nanospheres: Design and Applications
by Jing Li, Xiaojun Liu, Jiaoli Wang, Qi Jiang, Minhui Chen, Wei Zhang, Yu Chen, Ying Pu and Jin Huang
Chemistry 2023, 5(3), 1882-1910; https://doi.org/10.3390/chemistry5030129 - 29 Aug 2023
Viewed by 1554
Abstract
Self-assembled DNA nanospheres, as versatile and ideal vehicles, have offered new opportunities to create intelligent delivery systems for precise bioimaging and cancer therapy, due to their good biostability and cell permeability, large loading capacity, and programmable self–assembly behaviors. DNA nanospheres can be synthesized [...] Read more.
Self-assembled DNA nanospheres, as versatile and ideal vehicles, have offered new opportunities to create intelligent delivery systems for precise bioimaging and cancer therapy, due to their good biostability and cell permeability, large loading capacity, and programmable self–assembly behaviors. DNA nanospheres can be synthesized by the self–assembly of Y–shaped DNA monomers, ultra–long single-stranded DNA (ssDNA), and even metal–DNA coordination. Interestingly, they are size–controllable by varying some parameters including concentration, reaction time, and mixing ratio. This review summarizes the design of DNA nanospheres and their extensive biomedical applications. First, the characteristics of DNA are briefly introduced, and different DNA nanostructures are mentioned. Then, the design of DNA nanospheres is emphasized and classified into three main categories, including Y–shaped DNA unit self-assembly by Watson–Crick base pairing, liquid crystallization and the dense packaging of ultra–long DNA strands generated via rolling circle amplification (RCA), and metal–DNA coordination–driven hybrids. Meanwhile, the advantages and disadvantages of different self–assembled DNA nanospheres are discussed, respectively. Next, the biomedical applications of DNA nanospheres are mainly focused on. Especially, DNA nanospheres serve as promising nanocarriers to deliver functional nucleic acids and drugs for biosensing, bioimaging, and therapeutics. Finally, the current challenges and perspectives for self-assembled DNA nanospheres in the future are provided. Full article
Show Figures

Figure 1

12 pages, 4698 KiB  
Article
Insight into the Adsorption Behavior of Carbon Nanoparticles Derived from Coffee Skin Waste for Remediating Water Contaminated with Pharmaceutical Ingredients
by Mutaz Salih, Babiker Y. Abdulkhair and Mansour Alotaibi
Chemistry 2023, 5(3), 1870-1881; https://doi.org/10.3390/chemistry5030128 - 24 Aug 2023
Cited by 1 | Viewed by 1011
Abstract
Coffee skins, a cheap, agricultural waste, were carbonized in a tubular furnace under a nitrogen stream and then ball milled to fabricate coffee skin-carbon-nanoparticles (CCNPs). SEM showed 35.6–41.6 nm particle size. The 26.64 and 43.16 peaks in the XRD indicated a cubic graphite [...] Read more.
Coffee skins, a cheap, agricultural waste, were carbonized in a tubular furnace under a nitrogen stream and then ball milled to fabricate coffee skin-carbon-nanoparticles (CCNPs). SEM showed 35.6–41.6 nm particle size. The 26.64 and 43.16 peaks in the XRD indicated a cubic graphite lattice. The FT-IR broadband revealed a 2500–3500 cm−1 peak, suggesting an acidic O-H group. CCNPs possessed a type-H3-loop in the N2-adsorption-desorption analysis, with a surface of 105.638 m2 g−1. Thereafter, CCNPs were tested for ciprofloxacin (CPXN) adsorption, which reached equilibrium in 90 min. CCNPs captured 142.6 mg g−1 from 100 mg L−1 CPXN, and the 5:12 sorbent mass-to-solution volume ratio was suitable for treating up to 75 mg L−1 contamination. The qt dropped from 142.6 to 114.3 and 79.2 mg g−1 as the temperature rose from 20 °C to 35 °C and 50 °C, respectively, indicating exothermic adsorption. CPXN removal efficiency decreased below pH 5.0 and above pH 8.0. Kinetically, CPXN adsorption fits the second-order model and is controlled by the liquid-film mechanism, indicating its preference for the CCNPs’ surface. The adsorption agreement with the liquid-film and Freundlich models implied the ease of CPXN penetration into the CCNP inner shells and the multilayered accumulation of CPXN on the CCNPs’ surface. The negative ∆H° and ∆G° revealed the exothermic nature and spontaneity of CPXN adsorption onto the CCNP. The CCNPs showed an efficiency of 95.8% during four consecutive regeneration-reuse cycles with a relative standard deviation (RSD) of 3.1%, and the lowest efficiency in the fourth cycle was 92.8%. Full article
(This article belongs to the Special Issue Low-Cost Water Treatment - New Materials and New Approaches)
Show Figures

Figure 1

15 pages, 2813 KiB  
Article
Optimization of Enzymatic Synthesis of D-Glucose-Based Surfactants Using Supported Aspergillus niger Lipase as Biocatalyst
by Alexis Spalletta, Nicolas Joly and Patrick Martin
Chemistry 2023, 5(3), 1855-1869; https://doi.org/10.3390/chemistry5030127 - 23 Aug 2023
Cited by 1 | Viewed by 1173
Abstract
Surfactants are amphiphilic molecules with the ability to modify the surface tension between two surfaces. They can be obtained by various methods, the main one being synthetic, from petroleum-based substrates. Their universal use in a wide range of fields has created a global [...] Read more.
Surfactants are amphiphilic molecules with the ability to modify the surface tension between two surfaces. They can be obtained by various methods, the main one being synthetic, from petroleum-based substrates. Their universal use in a wide range of fields has created a global market and, consequently, ecological, and economic expectations for their production. Biocatalyzed processes, involving enzymes, can address this objective with processes complying with the principles of green chemistry: energy saving, product selectivity, monodispersity, and reduction in the use of solvents, with energy eco-efficiency. For example, fatty-acid carbohydrate esters are biobased surfactants that can be synthesized by lipases. In this work, we were interested in the synthesis of D-glucose lauric ester, which presents interesting properties described in the literature, with Aspergillus niger lipase, rarely described with sugar substrates. We optimized the synthesis for different parameters and reaction media. This lipase appeared to be highly selective for 6-O-lauroyl-D-glucopyranose. However, the addition of DMSO (dimethyl sulfoxide) as a co-solvent displays a duality, increasing yields but leading to a loss of selectivity. In addition, DMSO generates more complex and energy-intensive purification and processing steps. Consequently, a bio-sourced alternative as co-solvent with 2MeTHF3one (2-methyltetrahydrofuran-3-one) is proposed to replace DMSO widely described in the literature. Full article
(This article belongs to the Special Issue Green Chemistry—a Themed Issue in Honor of Professor James Clark)
Show Figures

Graphical abstract

12 pages, 2488 KiB  
Article
Tris(3-nitropentane-2,4-dionato-κ2 O,O′) Complexes as a New Type of Highly Energetic Materials: Theoretical and Experimental Considerations
by Danijela S. Kretić, Ivana S. Veljković and Dušan Ž. Veljković
Chemistry 2023, 5(3), 1843-1854; https://doi.org/10.3390/chemistry5030126 - 18 Aug 2023
Viewed by 1026
Abstract
Decreasing the sensitivity towards detonation of high-energy materials (HEMs) is the ultimate goal of numerous theoretical and experimental studies. It is known that positive electrostatic potential above the central areas of the molecular surface is related to high sensitivity towards the detonation of [...] Read more.
Decreasing the sensitivity towards detonation of high-energy materials (HEMs) is the ultimate goal of numerous theoretical and experimental studies. It is known that positive electrostatic potential above the central areas of the molecular surface is related to high sensitivity towards the detonation of high-energy molecules. Coordination compounds offer additional structural features that can be used for the adjustment of the electrostatic potential values and sensitivity towards detonation of this class of HEM compounds. By a careful combination of the transition metal atoms and ligands, it is possible to achieve a fine-tuning of the values of the electrostatic potential on the surface of the chelate complexes. Here we combined Density Functional Theory calculations with experimental data to evaluate the high-energy properties of tris(3-nitropentane-2,4-dionato-κ2 O,O′) (nitro-tris(acetylacetonato)) complexes of Cr(III), Mn(III), Fe(III), and Co(III). Analysis of the Bond Dissociation Energies (BDE) of the C-NO2 bonds and Molecular Electrostatic Potentials (MEP) showed that these compounds may act as HEM molecules. Analysis of IR spectra and initiation of the Co(AcAc-NO2)3 complex in the open flame confirmed that these compounds act as high-energy molecules. The measured heat of combustion for the Co(AcAc-NO2)3 complex was 14,133 J/g, which confirms the high-energy properties of this compound. The results also indicated that the addition of chelate rings may be used as a new tool for controlling the sensitivity towards the detonation of high-energy coordination compounds. Full article
(This article belongs to the Section Theoretical and Computational Chemistry)
Show Figures

Figure 1

11 pages, 1627 KiB  
Article
A Ratiometric Fluorescent Probe for pH Measurement over a Wide Range Composed of Three Types of Fluorophores Assembled on a DNA Scaffold
by Eiji Nakata, Khongorzul Gerelbaatar, Mashal Asif, Hiroaki Konishi, Yuya Shibano, Peng Lin and Takashi Morii
Chemistry 2023, 5(3), 1832-1842; https://doi.org/10.3390/chemistry5030125 - 17 Aug 2023
Viewed by 1181
Abstract
The desirable properties of the sophisticated fluorescent pH probe are ratiometric detection properties and a wide detection range. In this study, three types of fluorophores with different fluorescence properties were assembled on a DNA origami nanostructure. DNA nanostructure has the advantage of being [...] Read more.
The desirable properties of the sophisticated fluorescent pH probe are ratiometric detection properties and a wide detection range. In this study, three types of fluorophores with different fluorescence properties were assembled on a DNA origami nanostructure. DNA nanostructure has the advantage of being a scaffold that can assemble different types of fluorophores with control over their number and position. The defined number of three different fluorophores, i.e., pH-sensitive fluorescein (CF) and Oregon Green (OG), and pH-insensitive tetramethylrhodamine (CR), assembled on the DNA scaffold provided a ratiometric fluorescent pH probe with a wide pH detection range that could cover the variation of intracellular pH. Full article
Show Figures

Graphical abstract

17 pages, 3648 KiB  
Review
DNA Nanotechnology-Empowered Fluorescence Imaging of APE1 Activity
by Hui He, Xiaojun Liu, Yuchen Wu, Lanlin Qi, Jin Huang, Yan Zhou, Jiahao Zeng, Kemin Wang and Xiaoxiao He
Chemistry 2023, 5(3), 1815-1831; https://doi.org/10.3390/chemistry5030124 - 17 Aug 2023
Viewed by 1505
Abstract
Apurinic/apyrimidinic endonuclease 1 (APE1), also known as redox factor-1 (Ref-1), is a multifunctional protein that exists widely in living organisms. It can specifically recognize and cleave the DNA in apurinic/apyrimidinic (AP) sites in the base excision repair (BER) pathway, as well as regulate [...] Read more.
Apurinic/apyrimidinic endonuclease 1 (APE1), also known as redox factor-1 (Ref-1), is a multifunctional protein that exists widely in living organisms. It can specifically recognize and cleave the DNA in apurinic/apyrimidinic (AP) sites in the base excision repair (BER) pathway, as well as regulate the expression of genes to activate some transcription factors. The abnormal expression and disruptions in the biological functions of APE1 are linked to a number of diseases, including inflammation, immunodeficiency, and cancer. Hence, it is extremely desired to monitor the activity of APE1, acquiring a thorough understanding of the healing process of damaged DNA and making clinical diagnoses. Thanks to the advent of DNA nanotechnology, some nanodevices are used to image the activity of APE1 with great sensitivity and simplicity. In this review, we will summarize developments in DNA-nanotechnology-empowered fluorescence imaging in recent years for APE1 activity according to different types of DNA probes, which are classified into linear DNA probes, composite DNA nanomaterials, and three-dimensional (3D) DNA nanostructures. We also highlight the future research directions in the field of APE1 activity imaging. Full article
Show Figures

Figure 1

11 pages, 7000 KiB  
Article
Porous Natural Diamond with Embedded Metal (Pt0.50–Co0.50)
by Evgeny Filatov, Aleksei Chepurov, Valeri Sonin, Andrey Zadesenets, Sergey Gromilov and Egor Zhimulev
Chemistry 2023, 5(3), 1804-1814; https://doi.org/10.3390/chemistry5030123 - 14 Aug 2023
Viewed by 1223
Abstract
Natural diamond crystals with a highly porous surface were used as substrates for synthesizing single-phase bimetallic Pt–Co nanoparticles at temperatures of 500 °C and 800 °C. The metal nanoparticles inside the pores were determined to take the form of single-phase Pt0.50Co [...] Read more.
Natural diamond crystals with a highly porous surface were used as substrates for synthesizing single-phase bimetallic Pt–Co nanoparticles at temperatures of 500 °C and 800 °C. The metal nanoparticles inside the pores were determined to take the form of single-phase Pt0.50Co0.50 solid solutions with different degrees of superstructure ordering. A detailed characterization of both nanoalloys revealed a tetragonal symmetry with a space group, P4/mmm. For the sample obtained at 500 °C, the lattice parameters were a = 2.673(2), c = 3.735(3) Å, and c/a = 1.397(1); for the samples obtained at 800 °C, the parameters were—a = 2.688(2), c = 3.697(3) Å, and c/a = 1.375(1). Within the experimental parameters, no significant chemical interaction of the diamond with the Pt–Co particles was identified. The results demonstrate a strong anchoring effect of the metallic material within the etching pores. The successful synthesis of bimetallic Pt–Co particles embedded inside the caverns can facilitate a study of their magnetic properties. The presence of Pt–Co in specific diamond compositions can also be used for marking diamond crystals as a means for their subtle identification, as well as confirming the possibility of capturing significant amounts of metal along with diamonds during their dissolution in the deep Earth. Full article
(This article belongs to the Section Chemistry of Materials)
Show Figures

Figure 1

23 pages, 5605 KiB  
Review
Recent Advances in Dynamic DNA Nanodevice
by Qin Fan, Linzi Yang and Jie Chao
Chemistry 2023, 5(3), 1781-1803; https://doi.org/10.3390/chemistry5030122 - 10 Aug 2023
Viewed by 1630
Abstract
DNA nanotechnology has been widely used to fabricate precise nanometer-scale machines. In particular, dynamic DNA nanodevices have demonstrated their ability to mimic molecular motions and fluctuations in bion-anomic systems. The elaborately designed DNA nanomachines can conduct a variety of motions and functions with [...] Read more.
DNA nanotechnology has been widely used to fabricate precise nanometer-scale machines. In particular, dynamic DNA nanodevices have demonstrated their ability to mimic molecular motions and fluctuations in bion-anomic systems. The elaborately designed DNA nanomachines can conduct a variety of motions and functions with the input of specific commands. A dynamic DNA nanodevice with excellent rigidity and unprecedented processability allows for structural transformation or predictable behavior, showing great potential in tackling single-molecule sensing, drug delivery, molecular systems, and so on. Here, we first briefly introduce the development history of DNA nanotechnology. The driving energy of dynamic DNA nanomachines is also discussed with representative examples. The motor pattern of DNA nanomachines is classified into four parts including translational motion, shear motion, 360° rotation, and complex motion. This review aims to provide an overview of the latest reports on the dynamic DNA nanomachine and give a perspective on their future opportunities. Full article
Show Figures

Figure 1

11 pages, 12967 KiB  
Article
Blue-Emitting 2D- and 3D-Zinc Coordination Polymers Based on Schiff-Base Amino Acid Ligands
by Rodavgi Karakousi, Pinelopi A. Tsami, Maria-Areti I. Spanoudaki, Scott J. Dalgarno, Vassileios C. Papadimitriou and Constantinos J. Milios
Chemistry 2023, 5(3), 1770-1780; https://doi.org/10.3390/chemistry5030121 - 09 Aug 2023
Viewed by 1065
Abstract
The solvothermal reaction of Zn(NO3)2·4H2O, 1-OH-2-naphthaldehyde, and 2-methylalanine (mAla) in MeOH leads to the formation of complex {[ZnL1]}2n (1) (H2L1 = the Schiff-base resulting from the reaction [...] Read more.
The solvothermal reaction of Zn(NO3)2·4H2O, 1-OH-2-naphthaldehyde, and 2-methylalanine (mAla) in MeOH leads to the formation of complex {[ZnL1]}2n (1) (H2L1 = the Schiff-base resulting from the reaction of 1-OH-2-naphthaldehyde and mAla) in good yields. The structure of the neutral species, as determined by single-crystal crystallography, describes a two-dimensional coordination polymer, with repeating {Zn2} units bridged by syn, anti-carboxylate groups of the Schiff-base ligands. Repeating the same reaction using glycine (gly) instead of mAla leads to the formation of complex {[ZnL2]·0.33MeOH}3n (2.0.33MeOH) (H2L2 = the Schiff-base resulting from the reaction of 1-OH-2-naphthaldehyde and gly), again in good yields. Complex 2 describes a three-dimensional coordination polymer based on {Zn2} building blocks, arranged by anti, anti-carboxylate groups in a 3D motif. Complexes 1 and 2 were found to strongly emit at ~435 nm (λexc = 317 nm) both in solution and solid state, with complex 2 displaying a slightly longer lifetime of τav = 2.45 ns vs. τav = 2.02 ns for 1. Full article
Show Figures

Graphical abstract

10 pages, 1844 KiB  
Communication
Mechanochemistry through Extrusion: Opportunities for Nanomaterials Design and Catalysis in the Continuous Mode
by Oscar Trentin, Daniele Polidoro, Alvise Perosa, Enrique Rodríguez-Castellon, Daily Rodríguez-Padrón and Maurizio Selva
Chemistry 2023, 5(3), 1760-1769; https://doi.org/10.3390/chemistry5030120 - 08 Aug 2023
Cited by 2 | Viewed by 1420
Abstract
The potentialities of mechanochemistry trough extrusion have been investigated for the design of nanosized catalysts and their use in C-C bond-forming reactions. The mechanochemical approach proved successful for the synthesis of supported palladium nanoparticles with mean diameter within 6–10 nm, achieved by the [...] Read more.
The potentialities of mechanochemistry trough extrusion have been investigated for the design of nanosized catalysts and their use in C-C bond-forming reactions. The mechanochemical approach proved successful for the synthesis of supported palladium nanoparticles with mean diameter within 6–10 nm, achieved by the reduction of Pd(II) acetate with ethylene glycol, in the absence of any solvent. A mesoporous N-doped carbon derived from chitin as a renewable biopolymer, was used as a support. Thereafter, the resulting nanomaterials were tested as catalysts to implement a second extrusion based-protocol for the Suzuki-Miyaura cross-coupling reaction of iodobenzene and phenylboronic acid. The conversion and the selectivity of the reaction were 81% and >99%, respectively, with a productivity of the desired derivative, biphenyl, of 41 mmol gcat−1 h−1. Full article
(This article belongs to the Special Issue Green Chemistry—a Themed Issue in Honor of Professor James Clark)
Show Figures

Figure 1

15 pages, 1457 KiB  
Article
Ratiometric Detection of Zn2+ Using DNAzyme-Based Bioluminescence Resonance Energy Transfer Sensors
by Yuting Wu, Whitney Lewis, Jing Luen Wai, Mengyi Xiong, Jiao Zheng, Zhenglin Yang, Chloe Gordon, Ying Lu, Siu Yee New, Xiao-Bing Zhang and Yi Lu
Chemistry 2023, 5(3), 1745-1759; https://doi.org/10.3390/chemistry5030119 - 08 Aug 2023
Cited by 1 | Viewed by 2051
Abstract
While fluorescent sensors have been developed for monitoring metal ions in health and diseases, they are limited by the requirement of an excitation light source that can lead to photobleaching and a high autofluorescence background. To address these issues, bioluminescence resonance energy transfer [...] Read more.
While fluorescent sensors have been developed for monitoring metal ions in health and diseases, they are limited by the requirement of an excitation light source that can lead to photobleaching and a high autofluorescence background. To address these issues, bioluminescence resonance energy transfer (BRET)-based protein or small molecule sensors have been developed; however, most of them are not highly selective nor generalizable to different metal ions. Taking advantage of the high selectivity and generalizability of DNAzymes, we report herein DNAzyme-based ratiometric sensors for Zn2+ based on BRET. The 8-17 DNAzyme was labeled with luciferase and Cy3. The proximity between luciferase and Cy3 permitted BRET when coelenterazine, the substrate for luciferase, was introduced. Adding samples containing Zn2+ resulted in a cleavage of the substrate strand, causing dehybridization of the DNAzyme construct, thus increasing the distance between Cy3 and luciferase and changing the BRET signals. Using these sensors, we detected Zn2+ in serum samples and achieved Zn2+ detection with a smartphone camera. Moreover, since the BRET pair is not the component that determines the selectivity of the sensors, this sensing platform has the potential to be adapted for the detection of other metal ions with other metal-dependent DNAzymes. Full article
Show Figures

Graphical abstract

23 pages, 6049 KiB  
Article
New Functionalized Chitosan with Thio-Thiadiazole Derivative with Enhanced Inhibition of Pathogenic Bacteria, Plant Threatening Fungi, and Improvement of Seed Germination
by Ahmed G. Ibrahim, Walid E. Elgammal, Ahmed M. Eid, Maha Alharbi, Ahmad E. Mohamed, Aisha A. M. Alayafi, Saber M. Hassan and Amr Fouda
Chemistry 2023, 5(3), 1722-1744; https://doi.org/10.3390/chemistry5030118 - 08 Aug 2023
Cited by 1 | Viewed by 1162
Abstract
In this study, a new modified chitosan conjugate (Chito-TZ) was developed via amide coupling between the acid chloride derivative of the methylthio-thidiazole compound and the free primary amino groups of chitosan. The product was characterized using several instrumental investigations, including Fourier-transform infrared spectroscopy [...] Read more.
In this study, a new modified chitosan conjugate (Chito-TZ) was developed via amide coupling between the acid chloride derivative of the methylthio-thidiazole compound and the free primary amino groups of chitosan. The product was characterized using several instrumental investigations, including Fourier-transform infrared spectroscopy (FT-IR), 1H-Nuclear magnetic resonance, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). XRD indicated that the crystalline pattern of chitosan was interrupted after chemical modification with the thiadiazole derivative. Broido’s model was used to determine the thermal activation energy Ea, and the results showed that the Ea for the first decomposition region of Chito-TZ is 24.70 KJ mol−1 lower than that required for chitosan (95.57 KJ mol−1), indicating the accelerating effect of the thiadiazole derivative on the thermal decomposition of Chito-TZ. The modified chitosan showed better antibacterial and antifungal activities than the non-modified chitosan; except for seed germination, chitosan was better. The Chito-TZ showed a low MIC value (25–50 µg mL−1) compared to Chito (50–100 µg mL−1). Moreover, the maximum inhibition percentages for plant-pathogenic fungi, Aspergillus niger, Fusarium oxysporum, and Fusarium solani, were attained at a concentration of 300 µg mL−1 with values of 35.4 ± 0.9–39.4 ± 1.7% for Chito and 45.2 ± 1.6–52.1 ± 1.3% for Chito-TZ. The highest germination percentages (%) of broad bean, shoot and root length and weight, and seed vigor index were obtained after Chito treatment with a concentration of 200 µg mL−1 compared to Chito-TZ. Full article
(This article belongs to the Section Biological and Natural Products)
Show Figures

Figure 1

3 pages, 610 KiB  
Correction
Correction: Kurniawan et al. Vapor-Phase Oxidant-Free Dehydrogenation of 2,3- and 1,4-Butanediol over Cu/SiO2 Catalyst Prepared by Crown-Ether-Assisted Impregnation. Chemistry 2023, 5, 406–421
by Enggah Kurniawan, Shuya Hosaka, Masayuki Kobata, Yasuhiro Yamada and Satoshi Sato
Chemistry 2023, 5(3), 1719-1721; https://doi.org/10.3390/chemistry5030117 - 07 Aug 2023
Cited by 1 | Viewed by 644
Abstract
In the published article “Vapor-Phase Oxidant-Free Dehydrogenation of 2,3- and 1,4-Butanediol over Cu/SiO2 Catalyst Prepared by Crown-Ether-Assisted Impregnation“ [...] Full article
Show Figures

Figure 1

23 pages, 5246 KiB  
Review
Peptide-Based Vectors for Gene Delivery
by Juan Yang and Guo-Feng Luo
Chemistry 2023, 5(3), 1696-1718; https://doi.org/10.3390/chemistry5030116 - 05 Aug 2023
Cited by 3 | Viewed by 1841
Abstract
Gene therapy is the ultimate therapeutic technology for diseases related to gene abnormality. However, the use of DNA alone has serious problems, such as poor stability and difficulty in entering target cells. The development of a safe and efficient gene delivery system is [...] Read more.
Gene therapy is the ultimate therapeutic technology for diseases related to gene abnormality. However, the use of DNA alone has serious problems, such as poor stability and difficulty in entering target cells. The development of a safe and efficient gene delivery system is the cornerstone of gene therapy. Of particular interest, multifunctional peptides are rationally designed as non-viral vectors for efficient gene delivery. As components of gene delivery vectors, these peptides play critically important roles in skeleton construction, the implementation of targeting strategies, cell membrane penetration, endosome rupture, and nuclear transport. In recent years, the research of functional peptide-based gene delivery vectors has made important progress in improving transfection efficiency. The latest research progress and future development direction of peptide-based gene delivery vectors are reviewed in this paper. Full article
Show Figures

Figure 1

15 pages, 3777 KiB  
Article
Rare Nuclearities and Unprecedented Structural Motifs in Manganese Cluster Chemistry from the Combined Use of Di-2-Pyridyl Ketone with Selected Diols
by Katerina Skordi, Dimitris I. Alexandropoulos, Adeline D. Fournet, Nikos Panagiotou, Eleni E. Moushi, Constantina Papatriantafyllopoulou, George Christou and Anastasios J. Tasiopoulos
Chemistry 2023, 5(3), 1681-1695; https://doi.org/10.3390/chemistry5030115 - 01 Aug 2023
Viewed by 1021
Abstract
The combined use of di-2-pyridyl ketone ((py)2CO) with various diols in Mn cluster chemistry has afforded five new compounds, namely, [Mn11O2(OH)2{(py)2CO2}5(pd)(MeCO2)3(N3)3(NO [...] Read more.
The combined use of di-2-pyridyl ketone ((py)2CO) with various diols in Mn cluster chemistry has afforded five new compounds, namely, [Mn11O2(OH)2{(py)2CO2}5(pd)(MeCO2)3(N3)3(NO3)2(DMF)4](NO3)∙2DMF∙H2O (1∙2DMF∙H2O), [Mn11O2(OH)2{(py)2CO2}5(mpd)(MeCO2)3(N3)3(NO3)2(DMF)4](NO3) (2), [Mn12O4(OH)2{(py)2CO2}4(mpd)2(Me3CCO2)4(NO3)4(H2O)6](NO3)2∙2MeCN (3∙2MeCN), [Mn4(OMe)2{(py)2C(OMe)O}2(2-hp)2(NO3)2(DMF)2] (4), and [Mn7{(py)2CO2}4(2-hp)4(NO3)2(DMF)2](ClO4)∙DMF (5∙DMF) ((py)2CO22− and (py)2C(OMe)O = gem-diol and hemiketal derivatives of di-2-pyridyl ketone, pdH2 = 1,3-propanediol, mpdH2 = 2-metly-1,3-propanediol, 2-hpH2 = 2-(hydroxymethyl)phenol). Complexes 1 and 2 are isostructural, possessing an asymmetric [MnIII5MnII64-O)(μ3-O)(μ3-OH)(μ-OH)(μ3-OR)2(μ-OR)10(μ-N3)]8+ core. Compound 3 is based on a multilayer [MnIII8MnII44-O)23-O)23-OH)2(μ-OR)12]10+ core, while complex 4 comprises a defective dicubane core. The crystal structure of 5 reveals that it is based on an unusual non-planar [MnIII5MnII2(μ-OR)12]7+ core with a serpentine-like topology. Direct current (dc) magnetic susceptibility studies revealed the presence of dominant antiferromagnetic exchange interactions in complex 3, while ferromagnetic coupling between the Mn ions was detected in the case of compound 5. Fitting of the magnetic data for complex 4 revealed weak antiferromagnetic interactions along the peripheral MnII∙∙∙MnIII ions (Jwb = −0.33 (1) cm−1) and ferromagnetic interactions between the central MnIII∙∙∙MnIII ions (Jbb = 6.28 (1) cm−1). Full article
Show Figures

Graphical abstract

25 pages, 6722 KiB  
Review
Aptamer-Based Immune Drug Systems (AptIDCs) Potentiating Cancer Immunotherapy
by Hongjie Xiong, Liu Liu, Xiaohui Liu, Hui Jiang and Xuemei Wang
Chemistry 2023, 5(3), 1656-1680; https://doi.org/10.3390/chemistry5030114 - 30 Jul 2023
Viewed by 1741
Abstract
Aptamers are artificial oligonucleotides with excellent molecule-targeting ability. Compared with monoclonal antibodies, aptamers have the advantages of low cost, no batch effect, and negligible immunogenicity, making them promising candidates for cancer immunotherapy. To date, a series of aptamer agonists/antagonists have been discovered and [...] Read more.
Aptamers are artificial oligonucleotides with excellent molecule-targeting ability. Compared with monoclonal antibodies, aptamers have the advantages of low cost, no batch effect, and negligible immunogenicity, making them promising candidates for cancer immunotherapy. To date, a series of aptamer agonists/antagonists have been discovered and directly used to activate immune response, such as immune checkpoint blockade, immune costimulation, and cytokine regulation. By incorporating both tumor- and immune cell-targeting aptamers, multivalent bispecific aptamers were designed to pursue high tumor affinity and enhanced immune efficacy. More importantly, benefiting from feasible chemical modification and programmability, aptamers can be engineered with diverse nanomaterials (e.g., liposomes, hydrogels) and even living immune cells (e.g., NK cells, T cells). These aptamer-based assemblies exhibit powerful capabilities in targeted cargo delivery, regulation of cell–cell interactions, tumor immunogenicity activation, tumor microenvironment remodeling, etc., holding huge potential in boosting immunotherapeutic efficacy. In this review, we focus on the recent advances in aptamer-based immune drug systems (AptIDCs) and highlight their advantages in cancer immunotherapy. The current challenges and future prospects of this field are also pointed out in this paper. Full article
Show Figures

Graphical abstract

11 pages, 2464 KiB  
Article
Hydrothermally Synthesized Hydroxyapatite-Silica Composites with Enhanced Mechanical Properties for Bone Graft Applications
by Atiek Rostika Noviyanti, Juliandri Juliandri, Engela Evy Ernawati, Haryono Haryono, Solihudin Solihudin, Dina Dwiyanti, Azman Ma’amor, Ferli Septi Irwansyah and Sharifuddin Bin Md Zain
Chemistry 2023, 5(3), 1645-1655; https://doi.org/10.3390/chemistry5030113 - 28 Jul 2023
Cited by 1 | Viewed by 1212
Abstract
The demand for synthetic bone grafts has increased in recent years. Hydroxyapatite (HA) is one of the highly suitable candidates as a bone graft material due to its excellent biocompatibility and high osteoconductive properties with low toxicity. HA has disadvantageous mechanical strength showing [...] Read more.
The demand for synthetic bone grafts has increased in recent years. Hydroxyapatite (HA) is one of the highly suitable candidates as a bone graft material due to its excellent biocompatibility and high osteoconductive properties with low toxicity. HA has disadvantageous mechanical strength showing relatively fragile and brittle behavior due to its high hygroscopic properties. This leads to improper mechanical properties for such grafting applications. Therefore, HA should be combined with another material with similar biocompatibility and high hardness, such as SiO2. In this work, HA/SiO2 (HAS) composite material was prepared via a hydrothermal method to obtain the high purities of HA with a particle size of approximately 35 nm and around 50% crystallinity. It was found that the addition of SiO2 stimulated the composite system by forming an orthosilicic acid complex that can reduce the overall solution’s pH, thus contributing to the integrity and stability of the HAS composite. Therefore, higher SiO2 contents in the HAS composite can enhance its mechanical stability when immersed in simulated body fluid (SBF). Our work demonstrated that HAS can highly improve HA material’s hardness and mechanical stability under immersion of SBF. The Vickers test showed that the 0.05 GPa hardness in 10% SiO2 increased to 0.35 GPa hardness with the addition of 20% SiO2. The crystal structures of HAS were analyzed using X-ray diffraction, and the morphology of the HAS composites was observed under electron microscopy. Full article
Show Figures

Figure 1

11 pages, 2432 KiB  
Article
Construction of an ATP-Activated Y-Shape DNA Probe for Smart miRNA Imaging in Living Cells
by Wukun Zhong, Yanlin Zheng, Lei Huang, Chao Xing and Chunhua Lu
Chemistry 2023, 5(3), 1634-1644; https://doi.org/10.3390/chemistry5030112 - 27 Jul 2023
Viewed by 982
Abstract
A stringent DNA probe to profile microRNA (miRNA) expression within a specific cell remains a key challenge in biology. To address this issue, an intracellular ATP-activated Y-DNA probe for accurate imaging of miRNA in living cells was designed. Y-DNA was based on the [...] Read more.
A stringent DNA probe to profile microRNA (miRNA) expression within a specific cell remains a key challenge in biology. To address this issue, an intracellular ATP-activated Y-DNA probe for accurate imaging of miRNA in living cells was designed. Y-DNA was based on the fabrication of tripartite function modules, which consisted of a folate (FA)-modified targeting module, an ATP aptamer-sealed driver, and a miRNA sensing module. The Y-DNA probe could be specifically activated by ATP after it efficiently internalized into FA-receptor-overexpressed cells based on caveolar-mediated endocytosis, leading to the activation of the miRNA sensing module. The activated Y-DNA probe allowed for the imaging of miRNA in living cells with high sensitivity. The design of the ATP-activated Y-DNA sensor opens the door for bioorthogonal miRNA imaging and promotes the development of various responsive DNA molecular probes with enhanced anti-interference ability for clinical diagnosis. Full article
Show Figures

Figure 1

13 pages, 2517 KiB  
Article
Constructing a Triangle Ensemble of Pt Clusters for Enhanced Direct-Pathway Electrocatalysis of Formic Acid Oxidation
by Cheng Li, Zheng Tang, Lanlan Shi, Yongjia Li, Yingjie Ji, Kaixin Zhang, Zhiyu Yang and Yi-Ming Yan
Chemistry 2023, 5(3), 1621-1633; https://doi.org/10.3390/chemistry5030111 - 26 Jul 2023
Cited by 1 | Viewed by 987
Abstract
The pursuit of operational advancements in direct formic acid fuel cells (DFAFCs) necessitates the development of high-performance platinum (Pt)-based catalysts for formic acid electrooxidation (FAOR). However, FAOR on Pt-based catalysts follows a dual pathway mechanism, in which the direct pathway is a preferred [...] Read more.
The pursuit of operational advancements in direct formic acid fuel cells (DFAFCs) necessitates the development of high-performance platinum (Pt)-based catalysts for formic acid electrooxidation (FAOR). However, FAOR on Pt-based catalysts follows a dual pathway mechanism, in which the direct pathway is a preferred route due to its efficient dehydrogenation process. Conversely, the indirect pathway results in the generation of adsorbed CO species, a process that deleteriously poisons the active sites of the catalyst, with CO species only being oxidizable at higher potentials, causing a significant compromise in catalyst performance. Herein, we have successfully synthesized Pt-C3N4@CNT, where three Pt clusters are precisely dispersed in a triplet form within the C3N4 by virtue of the unique structure of C3N4. The mass activity for the direct pathway (0.44 V) delivered a current density of 1.91 A mgPt1, while the indirect pathway (0.86 V) had no obvious oxidation peak. The selectivity of Pt-C3N4@CNT catalysts for the direct pathway of FAOR was improved due to the special structure of C3N4, which facilitates the dispersion of Pt tri-atoms in the structure and the electronic interaction with Pt. In this study, we provide a new strategy for the development of highly active and selective catalysts for DFAFCs. Full article
Show Figures

Figure 1

22 pages, 6161 KiB  
Article
Structural and Magnetic Analysis of a Family of Structurally Related Iron(III)-Oxo Clusters of Metal Nuclearity Fe8, Fe12Ca4, and Fe12La4
by Alok P. Singh, ChristiAnna L. Brantley, Kenneth Hong Kit Lee, Khalil A. Abboud, Juan E. Peralta and George Christou
Chemistry 2023, 5(3), 1599-1620; https://doi.org/10.3390/chemistry5030110 - 24 Jul 2023
Viewed by 1406
Abstract
The synthesis, crystal structure, and magnetic characterization are reported for three new structurally related iron(III) compounds (NHEt3)[Fe8O5(OH)5(O2PPh2)10] (1), [Fe12 Ca4O10(O2CPh) [...] Read more.
The synthesis, crystal structure, and magnetic characterization are reported for three new structurally related iron(III) compounds (NHEt3)[Fe8O5(OH)5(O2PPh2)10] (1), [Fe12 Ca4O10(O2CPh)10(hmp)4] (2), and [Fe12La4O10(OH)4(tbb)24] (3), where hmpH is 2-(hydroxymethyl)pyridine and tbbH is 4-tBu-benzoic acid. 1 was obtained from the reaction of Fe(NO3)3·9H2O, diphenylphosphinic acid (Ph2PO2H), and NEt3 in a 1:4:16 molar ratio in MeCN at 50 °C; 2 was obtained from the reaction of [Fe3O(O2CPh)6(H2O)3](NO3), Ca(NO3)2, and NEt3 in a 1:1:4:2 ratio at 130 °C; and 3 was obtained from the reaction of Fe(NO3)3·9H2O, La(NO3)3·6H2O, 4-tBu-benzoic acid, and NEt3 in a 1:1:4:4 ratio in PhCN at 140 °C. The core of 1 consists of two {Fe43-O)2}8+ butterfly units stacked on top of each other and bridged by O2− and HO ions. The cores of 2 and 3 also contain two stacked butterfly units, plus four additional Fe atoms, two at each end, and four M atoms (M = Ca2+ (2); La3+ (3)) on the sides. Variable-temperature (T) and solid-state dc and ac magnetization (M) data collected in the 1.8–300 K range revealed that 1 has an S = 0 ground state, 2 has a χMT value at low T consistent with the central Fe8 in a local S = 0 ground state and the two Fe3+ ions in each end-pair to be non-interacting, whereas 3 has a χMT value at low T consistent with these end-pairs each being ferromagnetically coupled with S = 5 ground states, plus intermolecular ferromagnetic interactions. These conclusions were reached from complementing the experimental studies with the calculation of the various Fe2 pairwise Jij exchange couplings by DFT computations and by using a magnetostructural correlation (MSC) for polynuclear Fe3+/O complexes, as well as a structural analysis of the intermolecular contacts in the crystal packing of 3. Full article
Show Figures

Figure 1

11 pages, 3090 KiB  
Article
Low-Temperature Properties of the Sodium-Ion Electrolytes Based on EC-DEC, EC-DMC, and EC-DME Binary Solvents
by Denis S. Lutsenko, Ekaterina V. Belova, Maxim V. Zakharkin, Oleg A. Drozhzhin and Evgeny V. Antipov
Chemistry 2023, 5(3), 1588-1598; https://doi.org/10.3390/chemistry5030109 - 23 Jul 2023
Viewed by 1698
Abstract
Sodium-ion batteries are a promising class of secondary power sources that can replace some of the lithium-ion, lead–acid, and other types of batteries in large-scale applications. One of the critical parameters for their potential use is high efficiency in a wide temperature range, [...] Read more.
Sodium-ion batteries are a promising class of secondary power sources that can replace some of the lithium-ion, lead–acid, and other types of batteries in large-scale applications. One of the critical parameters for their potential use is high efficiency in a wide temperature range, particularly below 0 °C. This article analyzes the phase equilibria and electrochemical properties of sodium-ion battery electrolytes that are based on NaPF6 solutions in solvent mixtures of ethylene carbonate and diethyl carbonate (EC:DEC), dimethyl carbonate (EC:DMC), and 1,2-dimethoxyethane (EC:DME). All studied electrolytes demonstrate a decrease in conductivity at lower temperatures and transition to a quasi-solid state resembling “wet snow” at certain temperatures: EC:DEC at −8 °C, EC:DMC at −13 °C, and EC:DME at −21 °C for 1 M NaPF6 solutions. This phase transition affects their conductivity to a different degree. The impact is minimal in the case of EC:DEC, although it partially freezes at a higher temperature than other electrolytes. The EC:DMC-based electrolyte demonstrates the best efficiency at temperatures down to −20 °C. However, upon further cooling, 1 M NaPF6 in EC:DEC retains a higher conductivity and lower resistivity in symmetrical Na3V2(PO4)3-based cells. The temperature range from −20 to −40 °C is characterized by the strongest deterioration in the electrochemical properties of electrolytes: for 1 M NaPF6 in EC:DMC, the charge transfer resistance increased 36 times, and for 1 M NaPF6 in EC:DME, 450 times. For 1 M NaPF6 in EC:DEC, the growth of this parameter is much more modest and amounts to only 1.7 times. This allows us to consider the EC:DEC-based electrolyte as a promising basis for the further development of low-temperature sodium-ion batteries. Full article
(This article belongs to the Section Electrochemistry and Photoredox Processes)
Show Figures

Figure 1

Previous Issue
Next Issue
Back to TopTop