A microfluidic electrochemical device for high sensitivity biosensing: Detection of nanomolar hydrogen peroxide

作者:Chikkaveeraiah Bhaskara V; Liu Hongyun; Mani Vigneshwaran; Papadimitrakopoulos Fotios; Rusling James F*
来源:Electrochemistry Communications, 2009, 11(4): 819-822.
DOI:10.1016/j.elecom.2009.02.002

摘要

We report herein a simple device for rapid biosensing consisting of a single microfluidic channel made from poly(dimethylsiloxane) (PDMS) coupled to an injector, and incorporating a biocatalytic sensing electrode, reference and counter electrodes. The sensing electrode was a gold wire coated with 5 nm glutathione-decorated gold nanoparticles (AuNPs). Sensitive detection of H(2)O(2) based on direct bioelectrocatalysis by horseradish peroxidase (HRP) was used for evaluation. HRP was covalently linked the glutathione-AuNPs. This electrode presented quasi-reversible cyclic voltammetry peaks at -0.01 V vs. Ag/AgCl at pH 6.5 for the HRP heme Fe(III)/Fe(II) couple. Direct electrochemical activity of HRP was used to detect H(2)O(2) at high sensitivity with a detection limit of 5 nM in an unmediated system.