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Characterization of Polylactide-Stabilized Gold Nanoparticles and Its Application in the Fabrication of Electrochemical DNA Biosensors
摘要： In this work, two different approaches to gold nanoparticles (AuNPs) have been explored for the modification of screen-printed electrode based on AuNPs and AuNPs stabilized with polylactic acid (PLA). The modified substrate has been characterized using UV-Vis spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM) and cyclic voltammetry. Both synthesized AuNPs were studied in terms of stability, sensitivity and reproducibility to enhance the sensing capability of modified electrodes. The PLA-stabilized AuNPs form strong structured nanoparticles and stabilize in aqueous solution. A larger active surface area (0.41 cm2) and lower charge transfer resistance (Rct) value were reported in the modification of sensing material with PLA-stabilized AuNPs, which resulted in enhancement of sensitivity. Therefore, AuNPs in PLA can be used as a potential alternative modifier for sensing chemicals and biomolecules in electrochemical sensors.
关键词： gold nanoparticles,polylactic acid,screen-printed carbon electrode,electrochemical DNA biosensor
更新于2025-09-09 09:28:46
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Protein Phosphorylation || FRET-Based Biosensors: Genetically Encoded Tools to Track Kinase Activity in Living Cells
摘要： Fluorescence microscopy is widely used in biology to localize, to track, or to quantify proteins in single cells. However, following particular events in living cells with good spatio-temporal resolution is much more complex. In this context, Forster resonance energy transfer (FRET) biosensors are tools that have been developed to monitor various events such as dimerization, cleavage, elasticity, or the activation state of a protein. In particular, genetically encoded FRET biosensors are strong tools to study mechanisms of activation and activity of a large panel of kinases in living cells. Their principles are based on a conformational change of a genetically encoded probe that modulates the distance between a pair of fluorescent proteins leading to FRET variations. Recent advances in fluorescence microscopy such as fluorescence lifetime imaging microscopy (FLIM) have made the quantification of FRET efficiency easier. This review aims to address the different kinase biosensors that have been developed, how they allow specific tracking of the activity or activation of a kinase, and to give an overview of the future challenging methods to simultaneously track several biosensors in the same system.
关键词： multiplex,biosensor,fluorescence microscopy,FRET,protein conformation,kinase
更新于2025-09-09 09:28:46
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A novel functionalized black phosphorus nanocomposite for biosensing
摘要： A novel functionalized black phosphorus (BP) nanocomposite was synthesized through a facile strategy by non-covalently and ionic combining liquid poly(diallyldimethylammonium chloride) (PDDA) with BP. The resultant nanocomposite exhibited good biocompatibility, favorable the solubility and enhanced electric conductivity facilitate to the immobilization of hemoglobin (Hb) and realize fast direct electron transfer with a rate constant (kET) of 15.36 s-1. The immobilized Hb displayed desirable electro-catalytic activity toward nitrite reduction in the range of 80 μM to 3.8 mM with a detection limit of 3.65 μM. The present work advances a new way to construct novel bio-friendly BP-based biosensors, biofuel cells and bioelectronics with excellent sensitivity and stability.
关键词： poly(diallyldimethylammonium chloride),electrochemistry,black phosphorus,biosensor,ionic liquid
更新于2025-09-09 09:28:46
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Photoelectrochemical biosensor for hydroxymethylated DNA detection and T4-β-glucosyltransferase activity assay based on WS2 nanosheets and carbon dots
摘要： 5-Hydroxymethylcytosine (5hmC) plays an important role in switching genes on and off in mammals, and it is implicated in both embryonic development and cancer progression. Herein, a novel photoelectrochemical (PEC) biosensor was developed for 5hmC detection based on WS2 nanosheets as the photoactive material and boronic acid functionalized carbon dots (B-CDs) for signal amplification unit. This biosensor can also be used for T4-β-glucosyltransferase (β-GT) activity assessment. Firstly, WS2 nanosheets and gold nanoparticles (AuNPs) were immobilized on an ITO electrode surface. Then probe DNA was immobilized on this electrode surface via Au-S bond. Afterwards, the complementary DNA containing 5hmC was then captured on the modified electrode surface by hybridization. Subsequently, β-GT transferred glucose from uridine diphosphoglucose to the hydroxyl groups of the 5hmC residues. After glycosylation, B-CDs could further be immobilized on the modified electrode surface resulting in a strong photocurrent. The PEC biosensor afforded high selectivity, excellent sensitivity and good reproducibility, with detection limits of 0.0034 nM and 0.028 unit/mL for 5hmC and β-GT, respectively. Results demonstrate that the photoelectrochemical strategy introduced here based on WS2 nanosheets and B-CDs offers a versatile platform for hydroxymethylated DNA detection, β-GT activity assessment and β-GT inhibitor screening.
关键词： Photoelectrochemical biosensor,DNA hydroxymethylation,β-Glucosyltransferase,WS2 nanosheets,carbon dots
更新于2025-09-09 09:28:46
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Organic field effect transistors (OFETs) in environmental sensing and health monitoring: A review
摘要： Organic field effect transistors (OFETs) have been the focus of sensing application research over the last two decades. In comparison to their inorganic counterparts, OFETs have multiple advantages, such as low-cost manufacturing, large area coverage, flexibility and readily tunable electronic material properties. To date, various organic semiconductors (OSCs), both polymers and small molecules, have been extensively researched for the purpose of developing the active channel layers in OFETs, enhancing their sensitivity and selectivity. However, OFET devices still need to be optimized to demonstrate reliable performance at the device level and in sensing applications. This review begins with an introduction of the OFETs with an emphasis on their geometry, materials (OSCs), fabrication process, and data analysis. After this, multiple applications are discussed and the progress regarding sensing elements and precisions is highlighted. In the end, the challenges and possible future directions of OFET arrays in embedded sensing platforms are presented.
关键词： stability,bi-layer,selectivity,biosensor,sensitivity,composites,OFETs,gamma irradiation,VOCs
更新于2025-09-09 09:28:46
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Silica Three-Dimensional Biosensors
摘要： Around the world, food-borne virus is one of the main pathogenic microorganisms in the aspect of causing people and animals with acute diarrhoea and poses a serious threat to human health. Therefore, the rapid detection of food-borne virus is very important to guarantee food safety and human health. Here, we reported that we developed a specific, convenient and fast detected method to detect rotavirus (RV) and hepatitis A virus (HAV) by using F0F1-ATPase molecular motor biosensor. Specific RNA probes were encompassed the conservative region of food-borne virus, and a molecular motor detect device was constructed by connecting probes to F0F1-ATPase molecular motor through biotin-streptavidin system. Extracted virus RNA was conjugated with the biosensor separately and meanwhile ATP was synthesized. By comparing their fluorescence intensity, virus RNA level was detected. Our results demonstrated that this biosensor’s sensitivity was the concentrations of 0.005 ng/mL and 0.01 ng/mL for RV and HAV respectively. Furthermore, this method possessed specificity for RV and HAV and none cross-reaction between them. What’s more, this method could be accomplished within 1h. We detected 15 samples by using this method and the results were consistent with RT-PCR results. Overall, this new-typed method based on F0F1-ATPase molecular motor biosensor for RV and HAV detection is sensitive and specific and can be used in the rapid detection of food-borne virus.
关键词： F0F1-ATPase,Detection,Molecular motor biosensor,Food-borne virus
更新于2025-09-04 15:30:14
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Fluorescent biosensor for detection of the R248Q aggregation‐prone mutant of p53
摘要： The p53 tumour suppressor and guardian of the genome undergoes missense mutations which lead to functional inactivation in 50% human cancers. These mutations occur mostly in the DNA-binding domain of the protein and several of these result in conformational changes which lead to amyloid-like protein aggregation. Here we describe a fluorescent biosensor that reports on the R248Q mutant of p53 in vitro and in living cells, engineered through conjugation of an environmentally-sensitive probe onto a peptide derived from the primary aggregation segment of p53.This biosensor was characterized both in vitro and by fluorescence microscopy following facilitated delivery into cultured cells. We show that this biosensor preferentially reports on the p53 R248Q mutant in PC9 lung cancer cell line compared to other lung cancer cell lines harbouring either wildtype or no p53.
关键词： p53,lung cancer,fluorescent biosensor,peptide,aggregation
更新于2025-09-04 15:30:14
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Paper-based miniaturized immunosensor for naked eye ALP detection based on digital image colorimetry integrated with smartphone
摘要： Alkaline phosphatase (ALP) is a metalloprotein found naturally in raw milk samples and is considered as an important biomarker in quality control of milk. Its easy, personalized, as well as instrument-less detection is important to ensure the pasteurization and its differentiation form raw milk. In view of such importance of APL, we have developed an office punching machine crafted paper biosensor for naked eye detection of ALP in milk samples. The quantitative estimation is done by digital image colorimetry (DIC) based technique integrated with smartphone. The sensor-probe was developed by the covalent immobilization of ALP antibody (anti-ALP) onto the functionalized paper surface. The fabrication of the biosensing probe was characterized using DIC, Fourier transform infrared spectroscopy (FTIR), and atomic force microscopy (AFM). The detection was based on immunocomplexation between the sensor-probe and ALP, which generates blue-green precipitate as an analytical signal by exploiting the catalytic activity of ALP towards 5-bromo-4-chloro 3-indolyl phosphate (BCIP). The dose dependent appearance of the blue-green complex was captured using smartphone camera and DIC was employed using Red, Green, and Blue (RGB) profiling system, where the maximum sensitivity was obtained for the red color channel. Based on the DIC analysis, a wide dynamic range for the ALP detection is obtained from 10-1000 U/mL with the detection limit of 0.87 (±0.07) U/mL. The designed paper-based biosensor is successfully applied to detect ALP in commercial and raw milk samples. Interferences due to components present in the milk samples was evaluated and the long-term stability of the designed biosensor was examined. Based on the detection principle, a miniaturized kit [20.0 mm (L) x 20.0 mm (W) x 2.15 mm (H)] was developed and applied for the ALP detection to demonstrate the instrument-free direct in-kitchen applicability.
关键词： Miniaturized prototype,Alkaline phosphatase,Paper biosensor,Digital image colorimetry,Bioanalysis
更新于2025-09-04 15:30:14
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Novel FRET-Based Src Biosensor Reveals Mechanisms of Src Activation and Its Dynamics in Focal Adhesions
摘要： Koudelkova′ et al. developed and functionally verified a Src kinase biosensor. The biosensor represents a unique tool to monitor Src structure, activity, and localization both in vitro and in cells. Using the biosensor, the action of Src inhibitors and Src dynamics in focal adhesions was described.
关键词： Src activation,Src inhibitors,focal adhesions,FRET-based Src biosensor,Src dynamics
更新于2025-09-04 15:30:14
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Enhanced Signal Amplification in a TLR-4 Biosensor Utilizing Ferrocene-Terminated Mixed Monolayers
摘要： A major challenge in effectively treating infections is to provide timely diagnosis of a bacterial or viral agent. Current cell culture methods require >24 hours to identify the cause of infection. The Toll-Like Receptor (TLR) family of proteins can identify classes of pathogens and has been shown to work well in an impedance-based biosensor, where the protein is attached to an electrode via a self-assembled monolayer (SAM). While the sensitivity of these sensors has been good, they contain a high resistance (>1 kΩ) SAM, generating relatively small signals and requiring longer data collection, which is ill-suited to implementation outside of a laboratory. Here, we describe a novel approach to increase the signal magnitude and decrease the measurement time of a TLR-4 biosensor by inserting a redox-active ferrocenyl-terminated alkane thiol into a mixed SAM containing hydroxyl- and carboxyl-terminated alkane thiols. The SAM formation and modification was confirmed via contact angle and X-ray photoelectron spectroscopy measurements, with TLR-4 immobilization demonstrated through a modified immunosorbent assay. It is shown that these TLR-4 biosensors respond selectively to their intended target, Gram-negative bacteria at levels between 100 and 105 lysed cells/mL, while remaining insensitive to Gram-positive bacteria or viral particles at up to 105 particles/mL. Furthermore, the signal enhancement due to the addition of ferrocene decreased the measurement time to less than one minute and has enabled this sensor to be used with an inexpensive, portable, handheld potentiostat that could be easily implemented in field settings.
关键词： TLR-4,Toll-Like Receptor biosensor,Gram-negative bacteria,ferrocene.,Mixed self-assembled monolayers
更新于2025-09-04 15:30:14