Urease enzyme as anodic catalyst in a microfluidic fuel cell

Abstract

In this research, enzymatic bioanodes based in urease enzyme were developed using graphene oxide as support material on porous electrodes, for application in microfluidic devices that use urea as fuel. Urease is a metalloenzyme that due to its bimetallic site is able to carry out the oxidation of urea with the formation of ammonia and carbonic acid. Graphene oxide was used because of its characteristics that favour the process of enzymatic immobilization. The performance of the microfluidic fuel cell was carried in the absence and in the presence of 0.1 M urea in 0.1M phosphates buffer where can observed an open circuit voltage above 1 V and important power density value when urea is used as fuel (2.82 mW cm-2). It was also evaluated by electrochemical techniques the effect of the concentration of urea on the power density generated by the microfluidic device, as well as stability, generating good energy conversion results for a first stage of research, where the objective is the creation of bioelectrodes with urease enzyme immobilized for application in Lab-on-a-Chip devices.