Mobile Water Kit (MWK): a smartphone compatible low-cost water monitoring system for rapid detection of total coliform and E. coli†
In this work, we have developed and demonstrated a rapid and low-cost water monitoring sensor that can simultaneously detect total coliform and Escherichia coli (E. coli) bacteria in contaminated drinking water samples. The test method, called Mobile Water Kit (MWK), comprises a set of custom chemical reagents that would serve as colorimetric or fluorometric chemosensors, syringe filter units and a smartphone platform that would serve as the detection/analysis system. The MWK provides information about the presence/absence of total coliform and E. coli in water samples. The MWK has preliminarily been tested for its selectivity, sensitivity and accuracy, with samples of known concentrations of bacteria. The MWK has also been tested with contaminated water samples collected during the two field trials conducted in Canada and India, and the obtained results were confirmed with conventional laboratory methods. With this MWK, we were able to detect the total coliform and E. coli bacteria in water samples within 30 min or less, depending on the concentration of the bacteria. For one of the field samples, the MWK was able to detect the total coliform within 35 s, which is faster than any rapid test methods available in the market. This new technology can dramatically improve the response times for the outbreak of water-borne diseases and will help water managers and individuals to assess the quality of water sources.