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Single-Atom Fe Nanozyme with Enhanced Oxidase-like Activity for the Colorimetric Detection of Ascorbic Acid and Glutathione

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Biosensors 2023, 13(4), 487; https://doi.org/10.3390/bios13040487 - 18 Apr 2023

Viewed by 609

Abstract

Single-atom nanozymes (SAzymes) have drawn ever-increasing attention due to their maximum atom utilization efficiency and enhanced enzyme-like activity. Herein, a facile pyrolysis strategy is reported for the synthesis of the iron–nitrogen–carbon (Fe-N-C) SAzyme using ferrocene trapped within porous zeolitic imidazolate framework-8 (ZIF-8@Fc) as [...] Read more.

Single-atom nanozymes (SAzymes) have drawn ever-increasing attention due to their maximum atom utilization efficiency and enhanced enzyme-like activity. Herein, a facile pyrolysis strategy is reported for the synthesis of the iron–nitrogen–carbon (Fe-N-C) SAzyme using ferrocene trapped within porous zeolitic imidazolate framework-8 (ZIF-8@Fc) as a precursor. The as-prepared Fe-N-C SAzyme exhibited exceptional oxidase-mimicking activity, catalytically oxidizing 3,3′,5,5′-tetramethylbenzidine (TMB) with high affinity (K_m) and fast reaction rate (V_max). Taking advantage of this property, we designed two colorimetric sensing assays based on different interaction modes between small molecules and Fe active sites. Firstly, utilizing the reduction activity of ascorbic acid (AA) toward oxidized TMB (TMBox), a colorimetric bioassay for AA detection was established, which exhibited a good linear range of detection from 0.1 to 2 μM and a detection limit as low as 0.1 μM. Additionally, based on the inhibition of nanozyme activity by the thiols of glutathione (GSH), a colorimetric biosensor for GSH detection was constructed, showing a linear response over a concentration range of 1–10 μM, with a detection limit of 1.3 μM. This work provides a promising strategy for rationally designing oxidase-like SAzymes and broadening their application in biosensing. Full article

(This article belongs to the Special Issue Functional Nanomaterials for Biosensing)

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Open AccessArticle

Label-Free Detection of T4 Polynucleotide Kinase Activity and Inhibition via Malachite Green Aptamer Generated from Ligation-Triggered Transcription

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Biosensors 2023, 13(4), 449; https://doi.org/10.3390/bios13040449 - 31 Mar 2023

Viewed by 571

Abstract

Polynucleotide kinase (PNK) is a key enzyme that is necessary for ligation-based DNA repair. The activity assay and inhibitor screening for PNK may contribute to the prediction and improvement of tumor treatment sensitivity, respectively. Herein, we developed a simple, low-background, and label-free method [...] Read more.

Polynucleotide kinase (PNK) is a key enzyme that is necessary for ligation-based DNA repair. The activity assay and inhibitor screening for PNK may contribute to the prediction and improvement of tumor treatment sensitivity, respectively. Herein, we developed a simple, low-background, and label-free method for both T4 PNK activity detection and inhibitor screening by combining a designed ligation-triggered T7 transcriptional amplification system and a crafty light-up malachite green aptamer. Moreover, this method successfully detected PNK activity in the complex biological matrix with satisfactory outcomes, indicating its great potential in clinical practice. Full article

(This article belongs to the Special Issue Functional Nanomaterials for Biosensing)

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Open AccessArticle

A Schematic Colorimetric Assay for Sialic Acid Assay Based on PEG-Mediated Interparticle Crosslinking Aggregation of Gold Nanoparticles

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Biosensors 2023, 13(2), 164; https://doi.org/10.3390/bios13020164 - 20 Jan 2023

Cited by 1 | Viewed by 1104

Abstract

Sialic acid (SA) is a well-known component of glycoproteins, which have applications in various functional processes on the cell’s surface. The colorimetric is a simpler and more convenient method for measuring SA due to its low-cost apparatus and visual signal changes. This work [...] Read more.

Sialic acid (SA) is a well-known component of glycoproteins, which have applications in various functional processes on the cell’s surface. The colorimetric is a simpler and more convenient method for measuring SA due to its low-cost apparatus and visual signal changes. This work focused on the unpredictable interparticle crosslinking aggregation of the functionalized gold nanoparticles (AuNPs) in complex media. We proposed a balance of the Derjaguin–Landau–Verwey–Overbeek (DLVO)-type aggregation and molecule-based interaction method to solve this problem. Here, we report a novel colorimetric assay for the determination of SA using 4-mercaptophenyl boronic acid (4-MPBA) as an analyte’s recognition molecule, and negative charge PEG₄₀₀ was used to repulsive the interparticle crosslinking. The proposed sensing platform shows a linear relationship between the ratio of the absorbance intensity (A₅₂₅/A₆₆₀) and concentration of SA from 0.05 to 8 mM (R² = 0.997) and a detection limit of 48 μM was observed. The novel gold-based colorimetric sensor is easy to fabricate, reproducible in its test performance and has been successfully applied for the detection of SA in biological and healthcare product samples. Full article

(This article belongs to the Special Issue Functional Nanomaterials for Biosensing)

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Open AccessArticle

Peptide Nanosheet-Inspired Biomimetic Synthesis of CuS Nanoparticles on Ti₃C₂ Nanosheets for Electrochemical Biosensing of Hydrogen Peroxide

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Biosensors 2023, 13(1), 14; https://doi.org/10.3390/bios13010014 - 22 Dec 2022

Cited by 1 | Viewed by 919

Abstract

Hydrogen peroxide (H₂O₂) is one of the intermediates or final products of biological metabolism and participates in many important biological processes of life activities. The detection of H₂O₂ is of great significance in clinical disease monitoring, [...] Read more.

Hydrogen peroxide (H₂O₂) is one of the intermediates or final products of biological metabolism and participates in many important biological processes of life activities. The detection of H₂O₂ is of great significance in clinical disease monitoring, environmental protection, and bioanalysis. In this study, Ti₃C₂-based nanohybrids are prepared by the biological modification and self-assembled peptide nanosheets (PNSs)-based biomimetic synthesis of copper sulfide nanoparticles (CuS NPs), which show potential application in the fabrication of low-cost and high-performance electrochemical H₂O₂ biosensors. The synthesized CuS-PNSs/Ti₃C₂ nanohybrids exhibit excellent electrochemical performance towards H₂O₂, in which CuS NPs can catalyze the decomposition of H₂O₂ and realize the transformation from a chemical signal to an electrical signal to achieve the purpose of H₂O₂ detection. The prepared CuS-PNSs/Ti₃C₂-based electrochemical biosensor platform exhibits a wide detection range (5 μM–15 mM) and a low detection limit (0.226 μM). In addition, it reveals good selectivity and stability and can realize the monitoring of H₂O₂ in a complex environment. The successful biomimetic synthesis of CuS-PNSs/Ti₃C₂ hybrid nanomaterials provides a green and friendly strategy for the design and synthesis of functional nanomaterials and also provides a new inspiration for the construction of highly effective electrochemical biosensors for practical detection of H₂O₂ in various environments. Full article

(This article belongs to the Special Issue Functional Nanomaterials for Biosensing)

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Open AccessArticle

Procedural Data Processing for Single-Molecule Identification by Nanopore Sensors

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Biosensors 2022, 12(12), 1152; https://doi.org/10.3390/bios12121152 - 09 Dec 2022

Viewed by 657

Abstract

Nanopores are promising single-molecule sensing devices that have been successfully used for DNA sequencing, protein identification, as well as virus/particles detection. It is important to understand and characterize the current pulses collected by nanopore sensors, which imply the associated information of the analytes, [...] Read more.

Nanopores are promising single-molecule sensing devices that have been successfully used for DNA sequencing, protein identification, as well as virus/particles detection. It is important to understand and characterize the current pulses collected by nanopore sensors, which imply the associated information of the analytes, including the size, structure, and surface charge. Therefore, a signal processing program, based on the MATLAB platform, was designed to characterize the ionic current signals of nanopore measurements. In a movable data window, the selected current segment was analyzed by the adaptive thresholds and corrected by multi-functions to reduce the noise obstruction of pulse signals. Accordingly, a set of single molecular events was identified, and the abundant information of current signals with the dwell time, amplitude, and current pulse area was exported for quantitative analysis. The program contributes to the efficient and fast processing of nanopore signals with a high signal-to-noise ratio, which promotes the development of the nanopore sensing devices in various fields of diagnosis systems and precision medicine. Full article

(This article belongs to the Special Issue Functional Nanomaterials for Biosensing)

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Open AccessArticle

Bare Eye Detection of Bacterial Enzymes of Pseudomonas aeruginosa with Polymer Modified Nanoporous Silicon Rugate Filters

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Biosensors 2022, 12(12), 1064; https://doi.org/10.3390/bios12121064 - 22 Nov 2022

Viewed by 861

Abstract

The fabrication, characterization and application of a nanoporous Silicon Rugate Filter (pSiRF) loaded with an enzymatically degradable polymer is reported as a bare eye detection optical sensor for enzymes of pathogenic bacteria, which is devoid of any dyes. The nanopores of pSiRF were [...] Read more.

The fabrication, characterization and application of a nanoporous Silicon Rugate Filter (pSiRF) loaded with an enzymatically degradable polymer is reported as a bare eye detection optical sensor for enzymes of pathogenic bacteria, which is devoid of any dyes. The nanopores of pSiRF were filled with poly(lactic acid) (PLA), which, upon enzymatic degradation, resulted in a change in the effective refractive index of the pSiRF film, leading to a readily discernible color change of the sensor. The shifts in the characteristic fringe patterns before and after the enzymatic reaction were analyzed quantitatively by Reflectometric Interference Spectroscopy (RIfS) to estimate the apparent kinetics and its dependence on enzyme concentration. A clear color change from green to blue was observed by the bare eye after PLA degradation by proteinase K. Moreover, the color change was further confirmed in measurements in bacterial suspensions of the pathogen Pseudomonas aeruginosa (PAO1) as well as in situ in the corresponding bacterial supernatants. This study highlights the potential of the approach in point of care bacteria detection. Full article

(This article belongs to the Special Issue Functional Nanomaterials for Biosensing)

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Open AccessCommunication

Application of Heat-Enhancement for Improving the Sensitivity of Quartz Crystal Microbalance

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Biosensors 2022, 12(8), 643; https://doi.org/10.3390/bios12080643 - 15 Aug 2022

Cited by 2 | Viewed by 882

Abstract

The use of quartz crystal microbalance in trace mass detection is restricted by unsatisfactory sensitivity, especially in damping media, due to the worsening of the quality factor of the damping resonator. The enhancement of the sensor performance could be realized by increasing the [...] Read more.

The use of quartz crystal microbalance in trace mass detection is restricted by unsatisfactory sensitivity, especially in damping media, due to the worsening of the quality factor of the damping resonator. The enhancement of the sensor performance could be realized by increasing the innate resonant frequency of quartz oscillators. Herein, increased working temperature of QCM systems was proved to bring an enhancement of the original resonant frequency. In addition, the measurement of ion osmotic pressure, single layer formation and single nucleotide polymorphism (SNP) at different temperatures demonstrated that an increased working temperature could enhance the sensitivity and accuracy, suggesting a potential application in a series of trace detections. Full article

(This article belongs to the Special Issue Functional Nanomaterials for Biosensing)

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Stimulus-Responsive DNA Hydrogel Biosensors for Food Safety Detection

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Biosensors 2023, 13(3), 320; https://doi.org/10.3390/bios13030320 - 24 Feb 2023

Viewed by 969

Abstract

Food safety has always been a major global challenge to human health and the effective detection of harmful substances in food can reduce the risk to human health. However, the food industry has been plagued by a lack of effective and sensitive safety [...] Read more.

Food safety has always been a major global challenge to human health and the effective detection of harmful substances in food can reduce the risk to human health. However, the food industry has been plagued by a lack of effective and sensitive safety monitoring methods due to the tension between the cost and effectiveness of monitoring. DNA-based hydrogels combine the advantages of biocompatibility, programmability, the molecular recognition of DNA molecules, and the hydrophilicity of hydrogels, making them a hotspot in the research field of new nanomaterials. The stimulus response property greatly broadens the function and application range of DNA hydrogel. In recent years, DNA hydrogels based on stimulus-responsive mechanisms have been widely applied in the field of biosensing for the detection of a variety of target substances, including various food contaminants. In this review, we describe the recent advances in the preparation of stimuli-responsive DNA hydrogels, highlighting the progress of its application in food safety detection. Finally, we also discuss the challenges and future application of stimulus-responsive DNA hydrogels. Full article

(This article belongs to the Special Issue Functional Nanomaterials for Biosensing)

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