An Innovative Fast-Start Aerobic Anode Microbial Fuel Cell Biosensor for Copper Ion Detection

The potential of microbial fuel cells (MFCs) based biosensors for water monitoring and early warning is widely recognized. However, the formation of electrochemically active biofilms (EABs) in MFCs typically requires a lengthy time span, and these biosensors are predominantly used in anaerobic wastewater treatment, limiting their broader application and technological advancement. In this study, we sought to address these challenges by employing aerobic sludge as an inoculation source to construct an MFCs sensing system, which proved to be a highly effective approach. Our findings revealed that biofilms with stable electrochemical properties could be promptly formed within 13 hours, representing a more than 90% reduction in start-up time compared to previous studies. Moreover, toxicity tests demonstrated outstanding performance, with maximum inhibition rates of 19.99%, 46.65%, and 53.02% observed for copper (Cu2+) ions at respective concentrations of 1 mg/L, 10 mg/L, and 50 mg/L, highlighting the exceptional toxicity response of the system. Remarkably, the response time was found to decrease significantly with increasing copper ion concentrations. Our results thus open up new avenues for achieving rapid start-up of MFCs sensors and enhancing the applicability of MFCs based biosensing technology