A self-powered, three-component biosensor capable of killing bacteria in water samples has been developed by materials scientists and chemical engineers at Qingdao University in China.

The team developed a biosensor that could potentially be used in developing countries to make water safe for drinking.

Illustration of EBFCs-based self-powered biosensor for detection and in situ elimination of E. coli based on hollow MOF nanoreactors combined with CHA amplification. Source: Advanced Functional Materials (2025). DOI: 10.1002/adfm.202420480

To develop the three-component biosensor that does not degrade, the team turned first to an enzyme-based fuel cell for powering the cell. The enzymes produce electricity through chemical reactions that occur as soon as the sensor is placed in a sample of water. The team then added a hollow metal organic framework to prevent the power generator from losing stability.

The researchers then added the second component, which is a type of antibody known as an aptamer, which features DNA strands that bind with the exterior of an E. coli bacterium.

Finally, the third component is the component that kills the bacteria. According to the researchers, this was achieved via the oxidation of the silver nanoparticles used by the second component, wherein the oxidation produces hydrogen peroxide, which destroys the bacterium.

In the lab, the sensor detected E. coli at very low concentrations and killed 99.9% of bacteria in a given sample over the course of just a few hours. Further, the new biosensor could also distinguish among assorted types of bacteria — which is a suggestion that the biosensor might be capable of destroying other microbes as well, pending modification.

An article detailing the biosensor, “Self‐Powered Biosensor‐Based Multifunctional Platform for Detection and In Situ Elimination of Bacteria,” appears in the journal Advanced Functional Materials.