Pulse-Voltammetric Glucose Detection at Gold Junction Electrodes

Abstract

A novel glucose sensing concept based on the localized change or "modulation" in pH within a symmetric gold-gold junction electrode is proposed. A paired gold-gold junction electrode (average gap size ca. 500 nm) is prepared by simultaneous bipotentiostatic electrodeposition of gold onto two closely spaced platinum disk electrodes. For glucose detection in neutral aqueous solution, the potential of the "pH-modulator" electrode is set to -1.5 V vs saturated calomel reference electrode (SCE) to locally increase the pH, and simultaneously, either cyclic voltammetry or square wave voltammetry experiments are conducted at the sensor electrode. A considerable improvement in the sensor electrode response is observed when a normal pulse voltammetry sequence is applied to the modulator electrode (to generate "hydroxide pulses") and the glucose sensor electrode is operated with fixed bias at +0.5 V vs SCE (to eliminate capacitive charging currents). Preliminary data suggest good linearity for the glucose response in the medically relevant 1-10 mM concentration range (corresponding to 0.18-1.8 g L(-1)). Future electroanalytical applications of multidimensional pulse voltammetry in junction electrodes are discussed.

Dual-microdisk electrodes in transient generator–collector mode: Experiment and theory

“…Marken et al have investigated dual-microdisk systems in generator-collector mode, including transport junctions [46][47][48][49] and microwave enhanced analytical processes [45,50]. Zhang and Zhou [51] have published fabrication methods, and analysis of films on dual-microdisk electrode systems.…”

Electrochemical Investigation of Glucose Oxidation on a Glassy Carbon Electrode Using Voltammetric, Amperometric, and Digital Simulation Methods

“…Several techniques have been employed for the electrochemical detection of glucose. These include cyclic voltammetry (CV), amperometry, square wave voltammetry(SWV) and differential pulse voltammetry (DPV) . However, most of these studies emphasized on quantification of glucose in samples.…”

“…These include cyclic voltammetry (CV), amperometry, square wave voltammetry(SWV) and differential pulse voltammetry (DPV). [15][16][17] However, most of these studies emphasized on quantification of glucose in samples. For example, Pang et.…”

Inter-particle charge transfer in TiO2-phytate films: Generator–collector gold–gold junction transients

“…Fast diffusion processes within this junction are driven by opposite potentials applied to the generator and collector termini of the junction. These electrodes allow reaction intermediates to be investigated [27], electroanalytical processes to be enhanced [28], and local pH to be modulated [29]. Fabrication of gold-gold junction electrodes can be based on simultaneous metal electrodeposition [30], which offers a simpler ''lab-bench'' approach when compared for example to modern lithography techniques [31,32].…”