Non-destructive characterization of proton diffusion coefficient within live electroactive biofilm

As the foundation stone of bioelectrochemical systems (BESs), the maintenance of electroactive biofilm with good metabolic activity is essential to achieve high and stable performance. Since proton transport has significant impacts on the biofilm metabolic activity through the microenvironment pH, the investigation of proton transfer properties interior the biofilms is crucial for enhancing BES performance. Herein, the proton transport in elec-troactive biofilms is explored by in situ microelectrode measurements. It achieves a methodological innovation for measuring the diffusion coefficient in live biofilm under non-destructive conditions. The non-destructive measurement of diffusion coefficients in situ not only bring the results more closely to reality, but also en-riches the knowledge of biochemical processes occurring and physicochemical information. Combined with the mass transport and electricity production mathematical model, it is demonstrated that the accumulation of protons in biofilm is a key factor in inhibiting the electricity generation. The efficient characterization of proton transfer interior the biofilm provides a realistic guidance for the construction high performance BES.

Automated summary

Maintaining electroactive biofilms with good metabolic activity is essential for high and stable performance in bioelectrochemical systems (BESs). Proton transport plays a significant role in biofilm metabolic activity through microenvironment pH, making it crucial to investigate proton transfer properties within the biofilms to enhance BES performance. In this study, the proton transport in electroactive biofilms was explored using in situ microelectrode measurements, which innovatively measured the diffusion coefficient in live biofilms under non-destructive conditions. The non-destructive measurement of diffusion coefficients not only brings the results closer to reality, but also enriches the understanding of biochemical processes and physicochemical information. By combining with a mathematical model, it was demonstrated that the accumulation of protons in the biofilm is a key factor in inhibiting electricity generation. The efficient characterization of proton transfer within the biofilm provides realistic guidance for constructing high-performance BESs.