 The provision of safe drinking water and adequate sanitation in developing countries is essential. Current methods for ensuring the safety of water for consumption face high costs, complexity of use, and inability to function on site or in real time. Microbial fuel cells, MFCs, which utilize bacteria to generate electricity, offer a promising alternative for rapid and simple water quality monitoring. MFCs are easy to produce and maintain, and can be made cost effective depending on the material used. Research into MFC sensors for water quality monitoring is advancing rapidly, with many applications already being tested in developing countries. This article was authored by John Chiller and Mirella De Lorenzo.