A multipedal DNA walker for amplified detection of tumor exosomes

2020 ◽  
Vol 56 (37) ◽  
pp. 4982-4985 ◽  
Author(s):  
Peng Miao ◽  
Yuguo Tang
Keyword(s):  
Electrochemical Biosensor ◽  
Limit Of Detection ◽  
Dna Walker ◽  
Tumor Exosomes ◽  
Excellent Selectivity

A novel electrochemical biosensor for exosomes is proposed based on a multipedal DNA walking strategy. A limit of detection down to 6/μL is obtained with excellent selectivity.

Single-Particle Electrochemical Biosensor with DNA Walker Amplification for Ultrasensitive HIV-DNA Counting

2021 ◽  
Vol 93 (10) ◽  
pp. 4506-4512
Author(s):  
Fanwei Luo ◽  
Fei Chen ◽  
Yi Xiong ◽  
Zhen Wu ◽  
Xiuhua Zhang ◽  
...  
Keyword(s):  
Single Particle ◽  
Electrochemical Biosensor ◽  
Hiv Dna ◽  
Dna Walker

scholarly journals Laccase Electrochemical Biosensor Based on Graphene-Gold/Chitosan Nanocomposite Film for Bisphenol A Detection

2020 ◽  
Vol 16 (5) ◽  
pp. 570-579
Author(s):  
Fuzi M. Fartas ◽  
Jaafar Abdullah ◽  
Nor A. Yusof ◽  
Yusran Sulaiman ◽  
Mohd I. Saiman ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Electrochemical Biosensor ◽  
Limit Of Detection ◽  
Modified Electrodes ◽  
Electrochemical Performances ◽  
Carbon Electrode ◽  
Screen Printed Carbon Electrode ◽  
Laccase Enzyme ◽  
Bisphenol A Detection ◽  
Screen Printed

Background: Bisphenol A (BPA) is considered one of the most common chemicals that could cause environmental endocrine disrupting. Therefore, there is an increasing demand for simple, rapid and sensitive methods for BPA detection that result from BPA leaching into foods and beverages from storage containers. Herein, a simple laccase electrochemical biosensor was developed for the determination of BPA based on Screen-Printed Carbon Electrode (SPCE) modified graphenegold/ chitosan. The synergic effect of graphene-gold/chitosan nanocomposite as electrode modifier greatly facilitates electron-transfer processes between the electrolyte and laccase enzyme, thus leads to a remarkably improved sensitivity for bisphenol A detection. Methods: In this study, laccase enzyme is immobilized onto the Screen-Printed Carbon Electrode (SPCE) modified Graphene-Decorated Gold Nanoparticles (Gr-AuNPs) with Chitosan (Chit). The surface structure of nanocomposite was studied using different techniques including Field Emission Scanning Microscopy (FESEM), TRANSMISSION Electron Microscopy (TEM), Raman spectroscopy and Energy Dispersive X-ray (EDX). Meanwhile, the electrochemical performances of the modified electrodes were studied using Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV). Results: The developed laccase biosensor offered excellent analytical performance for the detection of BPA with a sensitivity of 0.271 μA/μM and Limit of Detection (LOD) of 0.023 μM, respectively. Moreover, the constructed biosensor showed good reproducibility, selectivity and stability towards BPA. The sensor has been used to detect BPA in a different type of commercial plastic products as a real sample and satisfactory result was obtained when compared with the HPLC method. Conclusion: The proposed electrochemical laccase biosensor exhibits good result which is considered as a promising candidate for a simple, rapid and sensitive method especially in the resource- limited condition.

Regenerable electrochemical biosensor for exosomes detection based on the dual-recognition proximity binding-induced DNA walker

2021 ◽  
Vol 349 ◽  
pp. 130765
Author(s):  
Yuehua Guo ◽  
Shihua Liu ◽  
Huili Yang ◽  
Po Wang ◽  
Qiumei Feng
Keyword(s):  
Electrochemical Biosensor ◽  
Dna Walker

scholarly journals DNAzyme-Functionalized R-Phycoerythrin as a Cost-Effective and Environment-Friendly Fluorescent Biosensor for Aqueous Pb2+ Detection

Sensors ◽  
2019 ◽  
Vol 19 (12) ◽  
pp. 2732 ◽  
Author(s):  
Jikui Wu ◽  
Yunfei Lu ◽  
Ningna Ren ◽  
Min Jia ◽  
Ruinan Wang ◽  
...  
Keyword(s):  
Health Care ◽  
Food Safety ◽  
Lake Water ◽  
Limit Of Detection ◽  
Cost Effective ◽  
Fluorescence Signal ◽  
Environment Friendly ◽  
Substrate Complex ◽  
Fluorescent Biosensor ◽  
Excellent Selectivity

The sensitive detection of Pb2+ is of significant importance for food safety, environmental monitoring, and human health care. To this end, a novel fluorescent biosensor, DNAzyme-functionalized R-phycoerythrin (DNAzyme-R-PE), was presented for Pb2+ analysis. The biosensor was prepared via the immobilization of Iowa Black® FQ-modified DNAzyme–substrate complex onto the surface of SPDP-functionalized R-PE. The biosensor produced a minimal fluorescence signal in the absence of Pb2+. However, Pb2+ recognition can induce the cleavage of substrate, resulting in a fluorescence restoration of R-PE. The fluorescence changes were used to measure sensitively Pb2+ and the limit of detection was 0.16 nM with a linear range from 0.5–75 nM. Furthermore, the proposed biosensor showed excellent selectivity towards Pb2+ even in the presence of other metal ions interferences and was demonstrated to successfully determine Pb2+ in spiked lake water samples.

scholarly journals Glucose Biosensor Based on Disposable Activated Carbon Electrodes Modified with Platinum Nanoparticles Electrodeposited on Poly(Azure A)

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4489 ◽  
Author(s):  
Francisco Jiménez-Fiérrez ◽  
María Isabel González-Sánchez ◽  
Rebeca Jiménez-Pérez ◽  
Jesús Iniesta ◽  
Edelmira Valero
Keyword(s):  
Platinum Nanoparticles ◽  
High Performance ◽  
Electrochemical Biosensor ◽  
Limit Of Detection ◽  
Electrochemical Measurement ◽  
Glucose Biosensor ◽  
Carbon Electrodes ◽  
Real Samples ◽  
Glucose Determination ◽  
Azure A

Herein, a novel electrochemical glucose biosensor based on glucose oxidase (GOx) immobilized on a surface containing platinum nanoparticles (PtNPs) electrodeposited on poly(Azure A) (PAA) previously electropolymerized on activated screen-printed carbon electrodes (GOx-PtNPs-PAA-aSPCEs) is reported. The resulting electrochemical biosensor was validated towards glucose oxidation in real samples and further electrochemical measurement associated with the generated H2O2. The electrochemical biosensor showed an excellent sensitivity (42.7 μA mM−1 cm−2), limit of detection (7.6 μM), linear range (20 μM–2.3 mM), and good selectivity towards glucose determination. Furthermore, and most importantly, the detection of glucose was performed at a low potential (0.2 V vs. Ag). The high performance of the electrochemical biosensor was explained through surface exploration using field emission SEM, XPS, and impedance measurements. The electrochemical biosensor was successfully applied to glucose quantification in several real samples (commercial juices and a plant cell culture medium), exhibiting a high accuracy when compared with a classical spectrophotometric method. This electrochemical biosensor can be easily prepared and opens up a good alternative in the development of new sensitive glucose sensors.

Magnetically induced self-assembly DNAzyme electrochemical biosensor based on gold-modified α-Fe2O3/Fe3O4 heterogeneous nanoparticles for sensitive detection of Ni2+

2021 ◽  
Author(s):  
Lulu Yu ◽  
Min Liu ◽  
Yanling Zhang ◽  
Yun Ni ◽  
Shaobo Wu ◽  
...  
Keyword(s):  
Self Assembly ◽  
Electrochemical Biosensor ◽  
Limit Of Detection ◽  
Sol Gel ◽  
Trisodium Citrate ◽  
Thiol Group ◽  
Differential Pulse ◽  
Electrochemical Sensing ◽  
Detection Range ◽  
Sensing Platform

Abstract A magnetically induced self-assembly DNAzyme electrochemical biosensor based on gold-modified α-Fe2O3/Fe3O4 heterogeneous nanoparticles was successfully fabricated to detect Nickel(II) (Ni2+). The phase composition and magnetic properties of α-Fe2O3/Fe3O4 heterogeneous nanoparticles controllably prepared by the citric acid (CA) sol-gel method were investigated in detail. The α-Fe2O3/Fe3O4 heterogeneous nanoparticles were modified by using trisodium citrate as reducing agent, and the magnetically induced self-assembly α-Fe2O3/Fe3O4-Au nanocomposites were obtained. The designed Ni2+-dependent DNAzyme consisted of the catalytic chain modified with the thiol group (S1-SH) and the substrate chain modified with methylene blue (S2-MB). The MGCE/α-Fe2O3/Fe3O4-Au/S1/BSA/S2 electrochemical sensing platform was constructed and differential pulse voltammetry (DPV) was applied for electrochemical detection. Under the optimum experimental parameters, the detection range of the biosensor was 100 pM-10 µM (R2= 0.9978) with the limit of detection (LOD) of 55 pM. The biosensor had high selectivity, acceptable stability, and reproducibility (RSD = 4.03%).

scholarly journals A Multiplex Electrochemical Biosensor for Bloodstream Infection Diagnosis

2016 ◽  
Vol 22 (4) ◽  
pp. 466-474 ◽  
Author(s):  
Jian Gao ◽  
Lindsie Jeffries ◽  
Kathleen E. Mach ◽  
David W. Craft ◽  
Neal J. Thomas ◽  
...  
Keyword(s):  
Bloodstream Infection ◽  
Ribosomal Rna ◽  
Electrochemical Biosensor ◽  
Limit Of Detection ◽  
Cross Reactivity ◽  
Microbiological Analysis ◽  
Pathogen Identification ◽  
Human Blood Samples ◽  
Species Specific ◽  
Specific Sequences

Accurate and timely detection of bacterial pathogens will improve the clinical management of infections. Herein, we demonstrate an electrochemical biosensor that directly detects bacteria in human blood samples, resulting in the rapid diagnosis of a bloodstream infection. The multiplex biosensor detects the species-specific sequences of the 16S ribosomal RNA of bacteria for pathogen identification in physiological samples without preamplification. The analytical performance characteristics of the biosensor, including the limit of detection and probe cross-reactivity, are evaluated systematically. The feasibility of the biosensor for a diagnosis of a bloodstream infection is demonstrated by identifying bacterial clinical isolates spiked in whole blood and blood culture samples that were tested positive for bacteria. The electrochemical biosensor correctly identifies all the species in the samples with 100% concordance to microbiological analysis.

A Novel NAD+/MWNTs Nanocomposite-Based Electrochemical Biosensor for Measuring Mevalonic Acid

2014 ◽  
Vol 605 ◽  
pp. 388-391 ◽  
Author(s):  
Rungtiva Palangsuntikul ◽  
Saithip Pakapongpan ◽  
Porntip Khownarumit ◽  
Werasak Surareungchai
Keyword(s):  
Electrocatalytic Activity ◽  
Electrochemical Biosensor ◽  
Limit Of Detection ◽  
Reductase Activity ◽  
Mevalonic Acid ◽  
Fast Response ◽  
Good Stability ◽  
Screen Printed Electrode ◽  
Hmg Coa Reductase ◽  
Coa Reductase

A novel, simple and precise electrochemical biosensor, was developed for measuring mevalonic acid (MA) concentration, which is thought to be a good indicator of HMG-CoA reductase activity. This sensor is based on noncovalent-linking NAD+/MWNTs nanocomposite coated on a screen-printed electrode (SPE). The resulting biosensor exhibited excellent electrocatalytic activity, fast response and good stability to MA. At the NAD+/MWNTs-modified SPE, the current is linear with the concentration of MA being within a concentration range from 18.1 to 145 μM with a limit of detection down to 4.25 μM (S/N = 3), and the sensor exhibited a sensitivity of 92.2 μA/mM.

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