A hydrogel based rapid test method for detection of Escherichia coli (E. coli) in contaminated water samples

Abstract

We have formulated a new chemical composition for rapid detection of Escherichia coli (E. coli) with currently available enzymatic substrates. We have evaluated the performance of the new chemical composition with different kinds of bacteria, and metallic and ionic interferences and optimized the chemical composition for rapid and specific detection of E. coli. We used a novel hydrogel based porous matrix to encapsulate the optimized chemical compounds and incorporated it within a readily available plunger-tube assembly. This overall system allows efficient, field deployable, rapid testing of water samples by simultaneously pre-concentrating and detecting E. coli within one integrated unit. We were able to detect E. coli concentrations of 4 × 10⁶ CFU mL⁻¹ to 4 × 10⁵ CFU mL⁻¹ within 5 min and 4 × 10⁴ CFU mL⁻¹ to 400 CFU mL⁻¹ within 60 min using the integrated plunger-tube assembly containing the hydrogel matrix.