In situ controllable synthesis of cotton-like polyaniline nanostructures for a H2O2 sensor using an embedded three-electrode microfluidic chip

Abstract

A robust embedded three-electrode microfluidic chip (TEMC) was designed for the in situ electrochemical synthesis of polyaniline (PANI) nanostructures. PANI doped with poly-vinylsulphonic acid (PVS) was electrochemically produced at a channel coated with a thin gold layer as the working electrode material. The resultant material formed a conductive monolithic PANI/PVS film with cotton-like nanostructures. The thickness and porosity of the polymeric material can be controlled by the polymerization conditions, i.e., the number of potential cycles. Horseradish peroxidase (HRP) was subsequently electrostatically immobilized on the monolithic PANI/PVS film. This modified PANI/PVS/HRP material, obtained using a TEMC, showed a good linear response over a range of 0.01-0.6 mM and 1-60 mM for hydrogen peroxide detection and exhibited good reproducibility. This TEMC design could provide a simple and reliable approach for enzyme-based biosensor fabrication.