Table 1.
Existing paper based test strips for the detection of E. coli.
The commercial product is denoted by “*”.
Fig 1.
Schematic of the DipTest device.
Fig 2.
Comparison of the DipTest device between (a) tested with DI water at room temperature (inset shows the scanning electron microscope (SEM) image of porous paper matrix) (b) tested with E. coli contaminated water (2 × 104 CFU/mL) at room temperature.
It is to be noted that the appearance of color on the used DipTest device represents the presence of E. coli.
Fig 3.
Development of pinkish red color on the DipTest device after 2 hrs based on the concentrations of E. coli (CFU/mL).
The control strip is with DI water, which shows no color.
Fig 4.
Comparison of DipTest wait (response) times for the appearance of the pinkish red color with respect to various dip times.
The plot is shown for various known concentrations of E. coli spiked water samples.
Table 2.
DipTest results for 40 different water samples used in this work.
Fig 5.
Representation of the use of DipTest device to test the water sample for the presence of E. coli bacteria.