Stabilization of bilirubin oxidase in a biogel matrix for high-performance gas diffusion electrodes

Enzyme immobilization on solid conducting surfaces faces challenges for practical applications in technologies such as biosensors and biofuel cells. Short-term stability, poor electrochemical performance, enzyme inhibition are some unsolved issues. Here, we show a simple methodology bilirubin oxidase (BOD) carbon-based gas diffusion electrode four-electron oxygen reduction reaction. BOD is incorporated into Nafion® matrix crosslinked with glutaraldehyde by one-pot reaction buffered solution, producing stable BOD-based biogel. The biogel provides performance allows the direct electron-transfer mechanism of multicopper centers buried enzyme. A biocatalytic current −1.52 ± 0.24 mA cm −2 at 0.19 0.06 V was observed under conditions. Additionally, bioelectrode showed unprecedented long-term stability continuous operation combined satisfactory catalytic without redox mediator. layer thickness entrapment Nafion network crucial biocathode crosslinking contributes to enhance currents. Further, suitable microenvironment enzymatic activity involving three-phase interfacial present study new insights overcome critical short-term enzyme-based devices applications. • polymeric DET-type bioelectrocatalysis toward ORR. BOD-GDE -1.52 cm-2 high operation. Biogel stability.