Bioelectrocatalysis

Bioelectrocatalysis is the use of biological catalysts to drive electron transfer and chemical transformations at an electrode interface. It combines biochemistry, electrochemistry, and materials science to exploit enzymes, whole cells, and other biomolecules to perform redox reactions under mild, aqueous conditions. In bioelectrocatalysis, an electrode either accepts electrons from a biological catalyst or donates electrons to it, enabling applications in sensing and energy conversion.

Biocatalysts include oxidoreductase enzymes (for example glucose oxidase, laccase, hydrogenases, and dehydrogenases), as well as microorganisms such as yeast and bacteria, and photosynthetic systems. Electron transfer between the biocatalyst and the electrode can occur directly, via direct electron transfer (DET) when redox centers are in close contact with the surface, or indirectly, via mediators that shuttle electrons between the catalyst and the electrode.

Technologies in the field involve immobilization of biocatalysts on conductive supports such as carbon nanotubes, graphene, or carbon felt, and the use of conductive polymers or sol–gel matrices to enhance loading, stability, and conductivity. Approaches to promote DET and the use of redox mediators are common, as are strategies to preserve enzyme activity and facilitate mass transport.

Applications include biosensing (e.g., glucose, lactate, hydrogen peroxide detection) and bioelectrochemical energy systems such as enzymatic fuel cells and microbial fuel cells. Research also explores electrocatalytic synthesis and conversion of substrates like hydrogen, CO2, and nitrite.

Challenges include stability and deactivation of biocatalysts, fouling, mass transport limitations, and reproducibility, as well as integration into scalable devices. Advances in protein engineering, electrode design, and hybrid systems aim to enhance performance and practicality.