Scientists have developed a simple, paper-based device that can be used to test if a water sample is contaminated, providing a low-cost way for developing countries to limit the spread of water-borne diseases.
Inspired by the simplicity of litmus paper – commonly used for the rapid assessment of acidity in water.
The device consists of a microbial fuel cell (MFC), obtained by screen printing biodegradable carbon electrodes onto a single piece of paper.
An MFC is a device that uses the natural biological processes of ‘electric’ bacteria – attached to the carbon electrodes – to generate an electric signal.
When these bacteria are exposed to polluted water, a change in the electric signal occurs, which can be used as a warning message that the water is unsafe to drink.
