Recent Advances in the Direct Electron Transfer-Enabled Enzymatic Fuel Cells

Abstract

Direct electron transfer (DET), which requires no mediator to shuttle electrons from enzyme active site to the electrode surface, minimizes complexity caused by the mediator and can further enable miniaturization for biocompatible and implantable devices. However, because the redox cofactors are typically deeply embedded in the protein matrix of the enzymes, electrons generated from oxidation reaction cannot easily transfer to the electrode surface. In this review, methods to improve the DET rate for enhancement of enzymatic fuel cell performances are summarized, with a focus on the more recent works (past 10 years). Finally, progress on the application of DET-enabled EFC to some biomedical and implantable devices are reported.

Biofilm matrix and artificial mediator for efficient electron transport in CO2 microbial electrosynthesis

“…Such live-cell biocatalysts have the advantages of cost-effectiveness, high specificity, operation at room temperature and pressure, and self-replication. The electron delivery from the electrode to bacteria has been reported to use direct electron transport through the biofilm matrix [12][13][14][15] or indirect transfer via artificial or self-producing mediators, highlighting the need to investigate further improvements in the system performance [8,10,16]. Slow biofilm development on an electrode and low cell growth in suspension has frequently been highlighted as problems in Abbreviations: MES, Microbial electrosynthesis; NR, Neutral Red; HNQ, 2-hydroxy-1,4-naphthoquinone; OC, No mediator open circuit; MES, MES without a mediator; MES-NR, MES with NR; MES-HNQ, MES with HNQ.…”

Effects of cathode gas diffusion layer type and membrane electrode assembly preparation on the performance of immobilized glucose oxidase‐based enzyme fuel cell

“…were different. Nevertheless, power densities above 1 mW cm −2 were reported in other configurations available in the literature 3,39–42 …”

Magnetically Stimulated Bio‐ and Electrochemical Systems: State‐of‐the‐Art, Applications, and Future Directions

“…Some examples of them are third-generation biosensors [63] and microbial and enzymatic bio-fuel cells (BFCs) (BFCs). [64,65] On the other hand, in some particular cases, the MET approach was successfully implemented for highly sensitive and active biosensors. [66,67] To date, there are few significative reports approaching the DET from the use of microbes, [68][69][70][71] however about 100 enzymes, including alcohol dehydrogenase (ADH), [58] fructose dehydrogenase (FDH), [72] cytochrome c (Cyt c), [73,74] and glucose oxidase (GOx) [75,76] are known to be capable of working in DET conditions.…”