A device has been developed by scientists at the University of Bath which could help to detect levels of water pollution in lakes and rivers.
The device could be used in foreign countries where some water sources are not drinkable or clean to wash in.
It is seen as a cheaper way of detecting water pollution, with current methods considered expensive and time consuming.
Researchers from the university worked with the Bristol Robotics laboratory at the University of the West of England, to create the device which uses a sensor and 3D printing technology to help to monitor water quality.
Bacteria inside the device's sensor produce small electric currents, but these currents drop when the bacteria come into contact with toxins in the water, which shows level of water pollution.
University of Bath Chemical engineering lecturer, Dr Mirella Di Lorenzo, said: "When the bacteria feed in a microbial fuel cell, they convert chemical energy into electrical energy that we can measure.
"We found that when we injected a pollutant into the water there was an immediate drop in the electric current they produced. The drop was proportional to the amount of toxin present and the current is recovered once the toxin levels fell.
"This means we are able to monitor the level of pollutants in the water in real time without having to collect multiple samples and take them to a laboratory."