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 electrochemically active biofilms (EABs) are typically obtained under anaerobic conditions and the formation requires a lengthy time span, which critically limits the application and advancement of the MFCs based monitoring technology. To accelerate the formation rate of EABs and thus shorten the establishment time of MFCs to better meet the needs for early warning and detection of pollutants in the actual aerobic water environment, the aerobic sludge was employed as an inoculation source to construct the MFCs sensing system in this study. It was revealed that biofilms with stable electrochemical properties could be promptly formed within 35 h, reaching a level far ahead of previous studies. Moreover, toxicity tests for copper (Cu 2 + ) ions at concentrations of 1 mg/L, 10 mg/L, and 50 mg/L demonstrated outstanding performance with the maximum inhibition rates of 19.99 %, 46.65 %, and 53.02 % respectively. Remarkably, the response time was found to decrease significantly with the increase of copper ion concentrations. Our results thus open up a new avenue for achieving rapid start -up of MFCs in aerobic conditions, which facilitates the applicability of MFCs based biosensing technology.