TITLE:
A Rapid Low Power Ultra-Violet Light-Assisted Bacterial Sensor for Coliform Determination
AUTHORS:
Jia Shin Ho, Chee-Seng Toh
KEYWORDS:
Bacterial Sensor; Low Power; Cell Inactivation; E. coli; Coliform; Photocatalysis
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.4 No.10A,
September
26,
2013
ABSTRACT: Titanium dioxide (TiO2) particle-incorporated
Prussian blue (PB) sensor for the detection and inactivation of Escherichia coli (E. coli) is developed in
this study. The system requires low power ultra-violet (UV) light to photoactivate
TiO2 particles and change of signal response is measured immediately
upon irradiation using cyclic voltammetry. The generation of free radical
species (OH.) and H2O2 from the oxidation of water by the
hole (h+) are the main components
which cause destruction of cell membrane and eventually result in the
inactivation of cell. Our study also shows direct oxidation of cells by h+ as one of the mechanisms
for cell inactivation due to the close contact between TiO2 particles
and E. coli cells. Highly attractive features of this unique sensor
include its ability to be regenerated and reused for at least three times
without the use of harsh chemicals, good reproducibility and its specificity in
bacteria sensing when tested against organic contaminants, which potentially
reduce the operation cost when incorporated into water disinfection system. Its
superior performance in detection of total coliform without additional steps of
sample treatment is also demonstrated in
river water. TiO2 particle-incorporated PB membrane sensor exhibits
signal response with higher current output compared to PB-TiO2 coated screen printed carbon electrode (SPCE) due to its porous structure and
higher surface area, suggesting its potential development into a powerful
and low cost contamination monitoring tool.