Bath boffins put BUGS on chips – on purpose
Bacteria create cheap water-quality sensors
Don't debug this chip: boffins at the University of Bath have embedded bacteria on a chip to create a cheap water-quality sensor.
Instead of needing expensive lab kit to see if water is safe to drink – a serious problem anywhere the civil infrastructure is lacking – the bio-sensor contains bacteria that produce an electric current as they feed and grow.
If toxins in the water harm the bacteria, the electric current drops, something that's easy to measure and report on, they explain in the university's announcement.
The university quotes chemical engineering lecturer Dr Mirella Di Lorenzo's explanation of the chip's behaviour:
“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.”
Where mass spectrometry isn't available, the university says, researchers use fish or daphnia (small crustaceans) as bio-markers, but that's time consuming, and it's hard to get consistent results.
The work has been published in the journal Biosensors and Bioelectronics. ®