scholarly journals Accelerated Electron Transfer in Nanostructured Electrodes Improves the Sensitivity of Electrochemical Biosensors

2021 ◽  
pp. 2102495
Author(s):  
Kaiyu Fu ◽  
Ji‐Won Seo ◽  
Vladimir Kesler ◽  
Nicolo Maganzini ◽  
Brandon D. Wilson ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Electrochemical Biosensors ◽  
Nanostructured Electrodes

scholarly journals Accelerated electron transfer in nanostructured electrodes improves the sensitivity of electrochemical biosensors

2021 ◽  
Author(s):  
Kaiyu Fu ◽  
Ji-Won Seo ◽  
Vladimir Kesler ◽  
Nicolo Maganzini ◽  
Brandon D. Wilson ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Limit Of Detection ◽  
Low Cost ◽  
Fold Increase ◽  
Underlying Mechanism ◽  
Detection Sensitivity ◽  
Molecular Diagnostic ◽  
Electrochemical Biosensors ◽  
Electron Transfer Mechanism ◽  
Nanostructured Electrodes

Electrochemical biosensors hold the exciting potential to integrate molecular detection with signal processing and wireless communication in a miniaturized, low-cost system. However, as electrochemical biosensors are miniaturized to the micron scale, their detection sensitivity degrades precipitously, thereby greatly reducing their utility in the context of molecular diagnostic applications. Studies have reported that nanostructured electrodes can greatly improve electrochemical biosensor sensitivity, but the underlying mechanism remains poorly understood, thus making it difficult to fully exploit this phenomenon to improve biosensor performance. In this work, we propose and experimentally validate a novel mechanism in which electron transfer is physically accelerated within nanostructured electrodes due to reduced charge screening, resulting in enhanced sensitivity. We show that this mechanism can be exploited to achieve up to 24-fold increase in signal and nearly four-fold lower limit-of-detection relative conventional planar electrodes. This accelerated electron transfer mechanism should prove broadly applicable for improving the performance of electrochemical biosensors.

Electrochemical communication between microbial cells and electrodes via osmium redox systems

2012 ◽  
Vol 40 (6) ◽  
pp. 1330-1335 ◽  
Author(s):  
Kamrul Hasan ◽  
Sunil A. Patil ◽  
Dónal Leech ◽  
Cecilia Hägerhäll ◽  
Lo Gorton
Keyword(s):  
Electron Transfer ◽  
Biofuel Cells ◽  
Major Group ◽  
Electrochemical Biosensors ◽  
Bioelectrochemical Systems ◽  
Bacterial Cells ◽  
Redox Systems ◽  
Microbial Cells ◽  
Fundamental Part ◽  
Micro Organisms

Electrochemical communication between micro-organisms and electrodes is the integral and fundamental part of BESs (bioelectrochemical systems). The immobilization of bacterial cells on the electrode and ensuring efficient electron transfer to the electrode via a mediator are decisive features of mediated electrochemical biosensors. Notably, mediator-based systems are essential to extract electrons from the non-exoelectrogens, a major group of microbes in Nature. The advantage of using polymeric mediators over diffusible mediators led to the design of osmium redox polymers. Their successful use in enzyme-based biosensors and BFCs (biofuel cells) paved the way for exploring their use in microbial BESs. The present mini-review focuses on osmium-bound redox systems used to date in microbial BESs and their role in shuttling electrons from viable microbial cells to electrodes.

Direct Electron Transfer and Bioelectrocatalysis by a Hexameric, Heme Protein at Nanostructured Electrodes

2015 ◽  
Vol 27 (10) ◽  
pp. 2262-2267
Author(s):  
Johannes Tanne ◽  
Jae-Hun Jeoung ◽  
Lei Peng ◽  
Aysu Yarman ◽  
Birgit Dietzel ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Direct Electron Transfer ◽  
Heme Protein ◽  
Nanostructured Electrodes

Online electrochemical systems for continuous neurochemical measurements with low-potential mediator-based electrochemical biosensors as selective detectors

The Analyst ◽  
2015 ◽  
Vol 140 (15) ◽  
pp. 5039-5047 ◽  
Author(s):  
Zipin Zhang ◽  
Jie Hao ◽  
Tongfang Xiao ◽  
Ping Yu ◽  
Lanqun Mao
Keyword(s):  
Electron Transfer ◽  
Electrochemical Biosensor ◽  
Electrochemical Biosensors ◽  
Electrochemical Systems ◽  
Potential Mediator ◽  
New Strategy ◽  
Selective Detectors ◽  
Electron Mediators

This study demonstrates a new strategy to develop online electrochemical systems (OECSs) for continuously monitoring neurochemicals by efficiently integrating in vivo microdialysis with an oxidase-based electrochemical biosensor with low-potential electron mediators to shuttle the electron transfer of the oxidases.

scholarly journals Electrochemical Immunosensors with PQQ-Decorated Carbon Nanotubes as Signal Labels for Electrocatalytic Oxidation of Tris(2-carboxyethyl)phosphine

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1757
Author(s):  
Xiaohua Ma ◽  
Dehua Deng ◽  
Ning Xia ◽  
Yuanqiang Hao ◽  
Lin Liu
Keyword(s):  
Carbon Nanotubes ◽  
Electron Transfer ◽  
Direct Electron Transfer ◽  
Specific Antigen ◽  
Electrochemical Biosensors ◽  
Electron Mediator ◽  
High Turnover ◽  
Promising Alternative ◽  
Electrochemical Immunosensors ◽  
Sandwich Type

Nanocatalysts are a promising alternative to natural enzymes as the signal labels of electrochemical biosensors. However, the surface modification of nanocatalysts and sensor electrodes with recognition elements and blockers may form a barrier to direct electron transfer, thus limiting the application of nanocatalysts in electrochemical immunoassays. Electron mediators can accelerate the electron transfer between nanocatalysts and electrodes. Nevertheless, it is hard to simultaneously achieve fast electron exchange between nanocatalysts and redox mediators as well as substrates. This work presents a scheme for the design of electrochemical immunosensors with nanocatalysts as signal labels, in which pyrroloquinoline quinone (PQQ) is the redox-active center of the nanocatalyst. PQQ was decorated on the surface of carbon nanotubes to catalyze the electrochemical oxidation of tris(2-carboxyethyl)phosphine (TCEP) with ferrocenylmethanol (FcM) as the electron mediator. With prostate-specific antigen (PSA) as the model analyte, the detection limit of the sandwich-type immunosensor was found to be 5 pg/mL. The keys to success for this scheme are the slow chemical reaction between TCEP and ferricinum ions, and the high turnover frequency between ferricinum ions, PQQ. and TCEP. This work should be valuable for designing of novel nanolabels and nanocatalytic schemes for electrochemical biosensors.

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