title: A microfluidic electrochemical device for high sensitivity biosensing: detection of nanomolar hydrogen peroxide.
abstract: 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.
authors.affiliation: Department of Chemistry and Institute of Materials Science, University of Connecticut, Storrs, CT 06269.
authors.forename: Bhaskara V
authors.initials: BV
authors.lastname: Chikkaveeraiah
authors.forename: Hongyun
authors.initials: H
authors.lastname: Liu
authors.forename: Vigneshwaran
authors.initials: V
authors.lastname: Mani
authors.forename: Fotios
authors.initials: F
authors.lastname: Papadimitrakopoulos
authors.forename: James F
authors.initials: JF
authors.lastname: Rusling