A small team of materials scientists and chemical engineers at Qingdao University, in China, has developed a self-powered, three-component biosensor that can kill bacteria in water samples. The study is published in the journal Advanced Functional Materials.
As the world’s population continues to rise, scientists are looking for ways to sustain so many people. One area of concern is safe drinking water, particularly in regions that do not have sophisticated water treatment facilities. In this new effort, the team in China developed a biosensor that could, in theory, be used in developing countries to make water safe for drinking.
Biosensors are made using living organisms or tissues. Prior research has shown that they can be faster and less expensive than those based on traditional technology, especially in applications such as testing water for the presence of bacteria. Unfortunately, they tend to also suffer from degradation.
The researchers overcame this problem by creating their biosensor with three components. The first was an enzyme-based fuel cell to power the cell. The enzymes generate electricity via chemical reactions that occur once the sensor is placed in a water sample. To prevent their power generator from losing stability, the team put it in a hollow metal-organic framework.
The second component used a type of antibody known as an aptamer—their DNA strands were chosen specifically to bind with the exterior of an E. coli bacterium.
The third component was the part that kills the bacteria. It is accomplished by the oxidation of the silver nanoparticles used by the second component. The oxidation produces hydrogen peroxide, which kills the bacterium.
In testing, the sensor was capable of detecting E. coli at very low concentrations. It was also efficient, killing 99.9% of bacteria in a given sample over just a few hours. The biosensor also distinguished between different kinds of bacteria, suggesting it could be modified to kill other microbes as well. When tested on seawater samples, the sensor had recovery rates of 91.06% to 101.9% and remained workable after five user cycles.
More information: Yanfang Wang et al, Self‐Powered Biosensor‐Based Multifunctional Platform for Detection and In Situ Elimination of Bacteria, Advanced Functional Materials (2025). DOI: 10.1002/adfm.202420480
Journal information: Advanced Functional Materials