The complexity of monitoring water resources for the presence of hazardous mono-aromatic pollutants is eliminated with a biosensor engineered at the Indian Institute of Technology Bombay. The portable Arotrack device can be deployed by professionals and laymen alike to accurately detect phenol, benzene and other constituents in water.

Proteins typically found in bacteria living in heavily polluted environments are used to identify multiple xenobiotics. Once mixed in the water sample, the protein undergoes a highly selective adenosine triphosphate hydrolysis chemical reaction if an aromatic compound is present. The color of the protein solution will change to denote the presence of a target pollutant, which AroTrack can then detect.

“AroTrack contains a light emitting diode (LED)-phototransistor assembly, that shines a light of appropriate wavelength through the sample and detects how much is absorbed. A more intense color generates a higher absorbance,” explained the researchers.

Tests in simulated wastewater and actual environmental samples confirmed the utility of this approach in identifying pollutants at concentrations as low as 10 ppb to 200 ppb. The device described in Biosensors and Bioelectronics also operated reliably in water temperatures up to 50° C and completed the tests in under 30 minutes.