The interaction between microbes and electrodes decorated with bio‐reduced graphene oxide— from an electrochemical point of view

Abstract

BACKGROUND: The extracellular electron transfer (EET) between microbes and electrodes modified by graphene-based functional material has attracted increasing attention. EET is an important process through which the anode can act as the acceptor for the electrons produced via microbial respiration, and it also plays a key role in organic matter degradation and nutrient cycling in the environment. RESULTS: Our results showed that the interaction between microbes and carbon felt (CF) electrodes decorated with bio-reduced graphene oxide (GO-br) was significantly enhanced compared to that between the unmodified CF electrode and microbes. The promoted biological current production and cyclic voltammetric (CV) current response indicated the considerable electroactivity of the GO-br-CF electrode. diffusion resistance (R dif) of the GO-br-CF electrode decreased significantly by 97.3% from 2.76 × 10 5 ± 7644 Ω at the initial incubation stage to 7341 ± 1322 Ω after 58 h of incubation time for GO-br decoration. We also noticed that the GO-br-CF electrode intermittently poised at +0.1 V (vs Ag/AgCl/KCl sat.) was favorable for EET. The GObr-CF electrode, which enhanced MFC performance significantly, was further used as the anode in a microbial fuel cell (MFC). CONCLUSION: Overall, the results of this study indicated the decoration of CF electrode with GO-br could regulate the electrochemical activity of the electrode and the EET process between the microbes and electrode. The elevated electrochemical activity and EET were attributed to the rapid decrease in the diffusion resistance (R dif) of the GO-br-CF electrode.

Horseradish Peroxidase Labelled-Sandwich Electrochemical Sensor Based on Ionic Liquid-Gold Nanoparticles for Lactobacillus brevis

“…A further increasing of the R ct has been observed with the immobilization of BSA, L. brevis , HRP-anti- L. brevis and L. brevis, suggesting the successful modification of each step. The increase of R ct during the sensor fabrication is due to the formation of barriers during the antibody-antigen reaction [ 34 , 35 ]. On the other hand, the coating of ILs only affects the R ct slightly, suggesting the ILs is an ideal candidate for enhancing the loading performance of the electrode.…”