Fundamentals, Applications, and Future Directions of Bioelectrocatalysis

Abstract

Bioelectrocatalysis is an interdisciplinary research field combining biocatalysis and electrocatalysis via the utilization of materials derived from biological systems as catalysts to catalyze the redox reactions occurring at an electrode. Bioelectrocatalysis synergistically couples the merits of both biocatalysis and electrocatalysis. The advantages of biocatalysis include high activity, high selectivity, wide substrate scope, and mild reaction conditions. The advantages of electrocatalysis include the possible utilization of renewable electricity as an electron source and high energy conversion efficiency. These properties are integrated to achieve selective biosensing, efficient energy conversion, and the production of diverse products. This review seeks to systematically and comprehensively detail the fundamentals, analyze the existing problems, summarize the development status and applications, and look toward the future development directions of bioelectrocatalysis. First, the structure, function, and modification of bioelectrocatalysts are discussed. Second, the essentials of bioelectrocatalytic systems, including electron transfer mechanisms, electrode materials, and reaction medium, are described. Third, the application of bioelectrocatalysis in the fields of biosensors, fuel cells, solar cells, catalytic mechanism studies, and bioelectrosyntheses of high-value chemicals are systematically summarized. Finally, future developments and a perspective on bioelectrocatalysis are suggested.

The Use of Electroactive Halophilic Bacteria for Improvements and Advancements in Environmental High Saline Biosensing

“…In the last two decades, microbial whole-cell biosensors have shown great potential for use in areas of environmental monitoring and biomedical diagnostics [1,50,65]. Wholecell biosensors offer various advantages, including good sensitivity, high selectivity, and the ability for in situ, quantitative detection.…”

“…Wholecell biosensors offer various advantages, including good sensitivity, high selectivity, and the ability for in situ, quantitative detection. Therefore, these microbial-based biosensors have been successfully applied for food and drink analysis, environmental monitoring, biomedical diagnostics, and drug screening [1,50,65,66]. In this subsection, we provide an overview of the design of microbial electrochemical biosensors using halotolerant microbes, which have been utilized for seawater BOD and heavy-metal sensing [47].…”

“…Bioelectrochemical systems have become of great interest to the electrochemistry community for exploring avenues of renewable energy generation, biosensing systems, and bioelectrosynthesis [1][2][3]. Specifically, microbial electrochemical systems are fit for long-term environmental deployment suitable for wastewater management and monitoring applications [4][5][6].…”

Membrane Protein Modified Electrodes in Bioelectrocatalysis

“…Immobilising enzymes on the electrodes has several advantages for electrocatalysis and this review will consider only immobilised systems. It is important that the enzymes retain their structural integrity and catalytic activity upon immobilisation [24]. Unlike soluble proteins, transmembrane proteins exist within lipid membranes and, consequently, are less stable in an aqueous environment where the amphiphilic properties of membrane proteins can lead to aggregation and denaturation.…”

“…Various immobilisation methods have been developed to achieve efficient electron transfer between a membrane protein and an electrode. There are several aspects to consider when designing and assembling (membrane) protein modified electrodes for bioelectrocatalysis: (1) orientation of the protein on the electrode surface, (2) preservation of the protein structural integrity and functionality, (3) low overpotential to minimise the energy loss, (4) protein loading of the electrode [24,31,32]. Some methods developed for electrocatalysis using soluble proteins can be adapted to detergent solubilised membrane proteins.…”