A Dual‐Electrode Approach for Highly Selective Detection of Glucose Based on Diffusion Layer Theory: Experiments and Simulation

Abstract

A dual-electrode configuration for the highly selective detection of glucose in the diffusion layer of the substrate electrode is presented. In this approach, a glassy carbon electrode (GCE, substrate) modified with a conductive layer of glucose oxidase/Nafion/graphite (GNG) was used to create an interference-free region in its diffusion layer by electrochemical depletion of interfering electroactive species. A Pt microelectrode (tip, 5 microm in radius) was located in the diffusion layer of the GNG-modified GCE (GNG-G) with the help of scanning electrochemical microscopy. Consequently, the tip of the electrode could sense glucose selectively by detecting the amount of hydrogen peroxide (H2O2) formed from the oxidization of glucose on the glucose oxidase layer. The influences of parameters, including tip-substrate distance, substrate potential, and electrolyzing time, on the interference-removing efficiency of this dual-electrode approach have been investigated systematically. When the electrolyzing time was 30 s, the tip-substrate distance was 1.8 a (9.0 microm) (where a is the radius of the tip electrode), the potentials of the tip and substrate electrodes were 0.7 V and 0.4 V, respectively, and a mixture of ascorbic acid (0.3 mM), uric acid (0.3 mM), and 4-acetaminophen (0.3 mM) had no influence on the glucose detection. In addition, the current-time responses of the tip electrode at different tip-substrate distances in a solution containing interfering species were numerically simulated. The results from the simulation are in good agreement with the experimental data. This research provides a concept of detection in the diffusion layer of a substrate electrode, as an interference-free region, for developing novel microelectrochemical devices.

Preparation of grain size controlled boron-doped diamond thin films and their applications in selective detection of glucose in basic solutions

“…It is regarded that BDD thin film electrodes are inert for glucose oxidation [12,28]. However, some groups reported that glucose could be oxidized at metal-implanted BDD thin film electrodes [13,19,29] and bare BDD thin film electrode treated with the hydrogen flame [30], and similar types of CV curves were obtained, i.e., the forward and backward sweeps of CV curves have a same oxidation peak at about + 0.63 V vs. SCE and superpose nearly completely to each other.…”

Amperometric bienzyme glucose biosensor based on carbon nanotube modified electrode with electropolymerized poly(toluidine blue O) film

“…The electropolymerization of TBO on electrode surface has been reported in detail elsewhere [37,38]. A mediator glucose biosensor immobilizing glucose oxidase at electropolymerized PTBO film on carbon nanotube modified glass carbon electrode has been reported [39].…”

An electrochemical method for selective detection of dopamine by depleting ascorbic acid in diffusion layer

“…In recent years, Xia's group proposed and developed a concept of electrochemical depletion of electroactive species in diffusion layer for selective detection [1][2][3][4]. The depletion of interfering reactive species in the diffusion layer is a simple and reproducible method, which opens a new direction for interferent-depleted electrochemical sensors.…”

“…Xia's concept was first established with selective glucose detection in the presence of AA by adopting an SECM configuration of the two working electrodes to achieve overlapping of the diffusion layer [1,2]. The substrate electrode was served as an interferent-depleted micro-circumstance, while the tip electrode was used for detecting glucose by sensing hydrogen peroxide formed during the process of the oxidization of glucose on the glucose oxidase layer-coated substrate electrode.…”