Researchers have developed a biosensor that attaches to a smartphone and uses bacteria to detect unsafe arsenic levels. The device generates easy-to-interpret patterns similar to volume-bars that display the level of contamination.
The contamination of water by heavy metals is a worldwide health issue. UNICEF reports that arsenic-contaminated drinking water is consumed by more than 140 million people worldwide. In resource-limited countries, there is a lack of sufficiently skilled personnel and healthcare facilities to test water for contamination.
The new device could replace existing tests, which are difficult to use, need special laboratory equipment, and can produce toxic chemicals. The biosensor was developed by manipulating the genetic code of the bacteria Escherichia coli. Genetic components were added to act as amplifiers when arsenic is detected.
Researchers tested the arsenic sensors using environment samples from affected wells in Bangladesh, which suffers from some of the world’s highest levels of arsenic-contaminated ground water. Water samples were fed into a plastic device containing bacteria suspended in a gel. This produced fluorescent proteins that were visible in the presence of arsenic.
The approach could be used to detect other environmental toxins, diagnose diseases, and locate landmines.