Utilization of FAD-Glucose Dehydrogenase from <i>T. emersonii</i> for Amperometric Biosensing and Biofuel Cell Devices

Abstract

Flavin-dependent glucose dehydrogenases (FAD-GDH) are oxygen-independent enzymes with high potential to be used as biocatalysts in glucose biosensing applications. Here, we present the construction of an amperometric biosensor and a biofuel cell device, which are based on a thermophilic variant of the enzyme originated from <i>Talaromyces emersonii</i>. The enzyme overexpression in <i>Escherichia coli</i> and its isolation and performance in terms of maximal bioelectrocatalytic currents were evaluated. We examined the biosensor's bioelectrocatalytic activity in 2,6-dichlorophenolindophenol-, thionine-, and dichloro-naphthoquinone-mediated electron transfer configurations or in a direct electron transfer one. We showed a negligible interference effect and good stability for at least 20 h for the dichloro-naphthoquinone configuration. The constructed biosensor was also tested in interstitial fluid-like solutions to show high bioelectrocatalytic current responses. The bioanode was coupled with a bilirubin oxidase-based biocathode to generate 270 μW/cm² in a biofuel cell device.