A pH Based Test for Detection of Bacteria in Drinking Water

The technology offers:-

• On-site water detection technology for microbial contamination
• Innovative alternate to existing culture based techniques gives color-alarm for contamination
• Selectivity issue can be addressed by employing antibodies against the microbe to be detected

The technology offers rapid and sensitive colorimetric detection of pathogens in water based on metal nanoparticle-enzyme interaction. The intensity of color development depends upon the amount of bacterial contamination present in water sample. This novel field-friendly innovation provides instant visible color change seen via naked-eye with a sensitivity of 10³ cells.mL⁻¹. The technique involves a polymer or bioreceptor coated silver nanoparticles combining  catalytic activity of an enzyme that produces a colored end-point readout signal. The salient feature of the bioassay includes the co-presence of enzyme inhibitor and bioreceptor simultaneously on the surface of nanoparticles. If water is contaminated, the nanobioprobe gets entangled with microbe and  enzyme is rendered free in solution consequently its catalytic activity produces pink color. On the other hand if water is microbe-free, the nanobioprobe inhibits the activity of enzyme  producing yellow color. The dual activity of nanobioprobe has been demonstrated by three versions of the bioassay that are reproducible and are IPR protected.

There are three versions of water testing kit. 

• First version detects all Coliform bacteria in water.
• Second version detects LPS on bacterial surface.
• Third version detects specific bacterial species based on receptor coating onto the nanobioprobe.
• The most important advantage offered by the technology is its cost-effective, user friendly, rapid and onsite .