Modification of Abiotic–Biotic Interfaces with Small Molecules and Nanomaterials for Improved Bioelectronics

Abstract

Low efficiency of charge extraction (and conversely charge injection) across biotic-abiotic interfaces constitutes an obstacle to the integration of biological and electronic systems in high-performance bioelectronic devices. Advances in the promotion of charge transport across these typically non-conductive interfaces will have far-reaching implications in important applications such as alternative energy generation, bioelectrosynthesis, diagnostics, and environmental monitoring. This review highlights the use of synthetic materials to improve electrical interfacing between biological systems and electrodes, focusing specifically on whole cell bioelectrochemical systems. By taking advantage of a rich variety of materials chemistry and synthetic methodologies, significant improvements to the facilitation of charge transport across abiotic-biotic interfaces have been realized. The modifications of the bioelectronic interfaces presented herein include the use of organic small molecules, semiconducting and redox active polymers, inorganic nanoparticles, carbon nanotubes, graphene, hybrid organic-inorganic systems, and micro-/nanoelectrodes. However, design rules to guide material selection and choices regarding device architecture remain ambiguous. Establishment of a clearer understanding of bioelectronic charge transfer phenomena, their constituent pathways, and means of stimulating or selecting for different pathways is still work in progress. As such, great opportunities exist for materials scientists to contribute to these topics through design and implementation.

Electricity generation and bivalent copper reduction as a function of operation time and cathode electrode material in microbial fuel cells

“…7G) and CS (Fig. 7J) at the end of cycle 1, which provided a higher interfacial surface area for Cu(II) adsorption and an increase of the conductivity throughout the cathode [29]. Th ese observations were in good agreement with the improved electricity generation (Fig.…”

Two‐Dimensional Protein Crystals for Solar Energy Conversion

“…A similar enhancement has been measured with the addition of COEs in yeast and E. coli microbial fuel cells (MFCs). [ 5 ] On a per mg basis our combined PSI crystal and COE device produces an order of magnitude increased photocurrent over monolayer approaches of PSI on SAMs. A comparison of different approaches and previously measured cathodic photocurrents is provided in Table S1.…”

“…This hybrid interface design stabilizes PSI at a high surface concentration within a lipid environment and uses a conjugated oligoelectrolyte (COE) to assist in the electron transfer from the electrode to PSI. [ 5 ] The crystalline PSI within its membrane is aligned either electron transfer between cofactors and artifi cial electron acceptors/donors. This is in contrast to the stacked architecture of three dimensional (3D) crystals.…”

Redox-Polymers Enable Uninterrupted Day/Night Photo-Driven Electricity Generation in Biophotovoltaic Devices

“…polymethylene blue (PMB), polythionine or polymethylene green (PMG)) can be a stable and efficient alternative. 16 Indeed, by immobilising polymeric osmium complexes onto working electrodes, the biocatalytic performance of pure cultures of the cyanobacterium Leptolyngbya For the practical implementation of BPVs however, the use of a microbial consortium is considered advantageous over axenic cultures, because consortia typically produce higher electrical outputs and have higher resilience to variable physicochemical and process conditions. 1 In this study, we report for the first time on the significant enhancement of current output by a mat-building marine photosynthetic consortium dominated by cyanobacteria, through immobilization of polymerized osmium complexes or azine mediators onto photoelectrochemical cell anodes.…”