Conjugation of glucose oxidase and bilirubin oxidase bioelectrodes as biofuel cell in a finger-powered microfluidic platform

Abstract

In this study the development of a biofuel cell for potential application in microfluidics is described. The biocatalysts support is produced through vacuum-filtration of a Vulcan carbon black suspension resulting in flexible, paper-like electrodes. The glucose oxidase bioanode was assembled using an enzyme precipitate coating procedure whereas the biocathode was implemented by attaching bilirubin oxidase enzyme onto the carbon black surface via a pyrene intermediate. The bioelectrodes were first characterized by voltammetry and by chronoamperometry on their sensing ability towards the respective substrates, namely glucose and oxygen. Finally, bioanode and biocathode were integrated in a single-compartment of a heterogeneous poly (methyl methacrylate) - polydimethylsiloxane microfluidic platform and the power density produced was assessed. In 10 mM glucose solution at pH 7.0, the biofuel cell showed an open circuit potential (OCP) of 0.43 V and a maximum power density of about 28 μW cm−2 at 0.24 V. Also we demonstrate here the viability of human propelled fluidics by introducing in the microfluidic device a finger-pressure mechanism.