ChemRxiv
These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
Stabilization of Bilirubin Oxidase in a Biogel Matrix for High-performance Gas Diffusion Electrodes.pdf (1.51 MB)
0/0

Stabilization of Bilirubin Oxidase in a Biogel Matrix for High-performance Gas Diffusion Electrodes

preprint
submitted on 30.03.2020 and posted on 31.03.2020 by Graziela Sedenho, Ayaz Hassan, Lucyano Macedo, Frank Crespilho
Enzyme immobilization on solid conducting surfaces faces some challenges for practical applications in technologies such as biosensors and biofuel cells. Short-term stability, poor electrochemical performance, and enzyme inhibition are some issues that remain unsolved. Here, we propose a simple methodology for bilirubin oxidase (BOD) immobilization on carbon-based gas-diffusion electrodes for a four-electron electrochemical oxygen reduction reaction (ORR). The enzyme is incorporated into a Nafion® polymeric matrix and cross-linked with glutaraldehyde by a one-pot reaction in a buffered solution, producing a stable BOD-based biogel. The biogel prevents the formation of enzyme aggregates, producing a homogeneous bioelectrode surface, and allows access to the direct electron-transfer mechanism of multicopper centers buried in the enzyme. A biocatalytic reduction current of -1.52 ± 0.24 mA cm-2 at 0.19 ± 0.06 V was observed under gas-diffusion conditions. Additionally, the bioelectrode showed an unprecedented long-term stability under continuous operation combined with satisfactory catalytic current without redox mediator, demonstrating that the BOD-based biogel provides a suitable microenvironment for long-term enzymatic activity involving a bio-three-phase interfacial reaction. Therefore, the present study contributes new insights into enzyme immobilization to overcome the critical short-term stability issue of enzyme-based electrochemical devices for practical applications.

Funding

FAPESP process 2015/22973-6

FAPESP process 2017/20493-2

FAPESP process 2019/12053-8

FAPESP process 2019/15333-1

CAPES-PNPD

History

Email Address of Submitting Author

graziela.cs@usp.br

Institution

University of São Paulo, São Carlos Institute of Chemistry

Country

Brazil

ORCID For Submitting Author

0000-0001-8696-5978

Declaration of Conflict of Interest

No conflict of interest

Exports

Logo branding

Categories

Exports