Microbial Fuel Cell (MFC)-Based in-Situ Water Toxicity Biosensor for Monitoring Heavy Metals and BTEX

As the electricity is produced by exoelectrogenic bacteria in an microbial fuel cell (MFC), monitoring electrical signals from MFCs can provide a novel way of real-time health monitoring of many engineered systems and processes such as anaerobic digester systems. The purpose of this study was to investigate the potential of the MFC process as a water toxicity sensor for detecting toxins such as heavy metals and BTEX in the water. Cu²⁺, Hg²⁺, benzene, and xylene were selected as the representative toxicants and the toxicity response of the MFC biosensor was evaluated based on the inhibition ratio, indicative of the voltage changes when the toxicants were exposed to the anodic biofilm. It was found that the inhibition ratios were proportional to the concentrations of spiked toxicants. The toxicity responses toward heavy metals demonstrated an excellent linear relationship between the inhibition ratio and the toxicant concentration. Overall, this study demonstrated the potential of MFC technology as a water toxicity biosensor for real-time health monitoring.