Highly sensitive and reusable Pt-black microfluidic electrodes for long-term electrochemical sensing

Abstract

Highly sensitive, long-term stable and reusable microfluidics electrodes have been fabricated and evaluated using H 2 O 2 and hydroquinone as model analytes. These electrodes composed of a 300 nm Pt-black layer situated on a 5 μm thick electrodeposited Au layer, provide effective protection against electrooxidation of an underlying chromium adhesion layer. Using repeated cyclic voltammetric (CV) sweeps in flowing buffer solution, highly sensitive Pt-black working electrodes were realized with five-(four-) decade linear dynamic range for H 2 O 2 (hydroquinone) and low detection limit of 10 nM for H 2 O 2 and 100 nM for hydroquinone. Moreover, high sensitivity for H 2 O 2 was demonstrated at low (0.3 V vs. Ag/AgCl) oxidation potentials, together with long-term stability and reusability for at least 30 days. Microfluidic flow was employed for desorption and reactivation of the nominally planar Pt-black electrodes. Such electrocatalytic surface architecture should be appropriate for long-term electrochemical detection of various molecules and biomolecules as well as in reusable immunoassay configurations.

Edge-plane microwire electrodes for highly sensitive H2O2 and glucose detection

“…Electrochemical rebuilding of the Au working electrode together with Pt nanoparticles deposition increased surface area and electro-catalytic activity against H 2 O 2 detection. (Qiang et al 2010) Electrodeposition of o -phenylenediamine together with glucose-oxidase (GO x ) afforded glucose detection with improved sensitivity and selectivity (>95%) against common interference species ( i.e. ascorbic acid, uric acid and acetaminophen).…”

Enhancing the Sensitivity of Needle-Implantable Electrochemical Glucose Sensors via Surface Rebuilding

“…47,48 For this, the rebuilt gold surface was further decorated with platinum NPs in accordance with Reference 48. The sensitivity increase afforded by the platinum NPs was investigated against electro-oxidation of H 2 O 2 .…”

Theory, fabrication and applications of microfluidic and nanofluidic biosensors

“…Methods such as detachment lithography [117] and alterations to the photoresist spin step [118] have been shown to resolve this issue. This method is frequently used in micro/nanofluidic-based biosensors to fabricate fluidic channels [6,20,127] and is also used in the fabrication of silicon nanowires [24,95]. Typical feature sizes are in the several micrometres range with the smallest features of the order of 2-5 mm.…”