Construction of a Hydrogen Peroxide Biosensor on Interdigitated Microband Electrodes Fabricated by a Mix-and-Match Process

Abstract

A hydrogen peroxide biosensor was fabricated by immobilization of horseradish peroxidase (HRP) onto the surface of interdigitated microband electrodes. The interdigitated microband electrodes show an amplification factor of ∼9.1 with a collection efficiency of 0.97, demonstrating a high efficiency in generator-collector experiments. Electrochemical impedance spectroscopy was used to follow the biosensor assembly process on the surface of interdigitated microband electrodes step-by-step. When HRP is coated onto the interdigitated microband electrodes, the charge resistance increases significantly, proving the immobilization of HRP on electrode surface. The surface morphology of the HRP modified interdigitated microband electrode was characterized by atomic force microscopy (AFM). AFM images show that the HRP is covering the interdigitated microband electrodes surface evenly. The resulting hydrogen peroxide biosensor exhibits a sensitivity of 114.75 A M−1 cm−2, a detection limit of 9.96 μM, and a linear range up to 500 μM. The performance of the proposed biosensor is evaluated in the presence of potential interferences such as ascorbic acid and uric acid.