Design and Characterization of Hybrid Glucose-Powered Enzymatic Biofuel Cells Based on the Combination of Different...

This study highlights the development of 5 different membraneless glucose enzymatic biofuel cells, which are capable of operating in dual modes (biofuel cells and sensors). In these biofuel cells, different bioanodes were used, consisting of graphite rods (GRs) modified with gold nanoparticles (AuNPs), dendritic gold nanostructures (DAuNSs), or both types of above-mentioned nanostructures covered by cystamine (Cys), a redox mediator (1,10-phenathroline-5,6-dione (PD)), and differently immobilized glucose oxidase (GOx). The Cys-based self-assembled monolayer (SAM) provided a platform for covalent GOx immobilization on the surface of the above-mentioned gold-based structures. A single-compartment-based membraneless design was applied for all three here designed hybrid enzymatic biofuel cells (G-EBFCs), which were all powered by glucose. Electrically conducting nanocompounds served as support for immobilization, while PD served as a redox mediator to enhance the current of G-EBFCs. The electrochemical behavior of the fabricated bioanodes, assessed by G-EBFCs, was investigated by cyclic voltammetry (CV) and direct voltage measurements. Although both GR/Cys/AuNPs/PD/GOx and GR/AuNPs/Cys/PD/GOx bioanodes were characterized by rather high power density, surface concentration of GOx, sensitivity, and low limit of detection, the GR/AuNPs/Cys/PD/GOx bioanode was considered more suitable for glucose biosensing in real samples due to its long-term stability and excellent anti-interference capability. The technological challenges discussed in this study open new horizons for simpler and more cost-effective designs of hybrid G-EBFCs and glucose biosensors, suitable for biomedical applications and the monitoring of beverage quality.