Enhancing microbial adhesion and electron transfer of Shewanella oneidensis MR-1 with polyaniline-glucose-gelatin coating for bioelectrochemical applications

Enhancing bioelectrochemical performance through electrode modifications is critical for advancing microbial fuel cell (MFC) technology. This study investigates the effect of carbon cloth modifications using polyaniline (PANI), glucose, and gelatin on biofilm formation, charge transfer, and microbial viability. Cyclic voltammetry results of initial and 7-day performance demonstrate that PANI-glucose-gelatin-biofilm modified carbon cloth (MCC.B) exhibits highest maximum current and lowest charge transfer resistance when compared with a bare carbon cloth-biofilm system with (CC.G.B) and without (CC.B) the presence of dissolved glucose. Biofilm viability studies reveal that CC.G.B supports predominantly planktonic growth, limiting bacterial adhesion, while MCC.B achieves the highest biofilm formation (90.2 ± 0.2%) and charge storage capacity (174.9 ± 10.2 mC/cm 2 ), corresponding to an approximately 50-fold increase in CSC compared with a bare carbon cloth system (3.3 ± 0.3 mC/cm 2 ), highlighting the synergistic impact of surface modifications and microbial activity. These findings demonstrate that MCC.B facilitates extracellular electron transfer by optimizing bacterial adhesion and nutrient availability, making it a promising candidate for shortening start-up and improving early-stage bioelectrode performance, while longer-term stability remains to be established. This work provides new insights into electrode engineering strategies for maximizing microbial interaction and electrochemical performance in next-generation microbial electrochemical technologies.