Simple fabrication of an inexpensive impedance based sensor for contamination detection

Escherichia Coli (E-coli) is a bacterium commonly found in the environment, foods and intestines of people and animal. The presence of E-coli in water can severely threaten human health condition. The quality of drinking water is vital and avoid using contaminated water is a must. In fact, the water that contaminated by E-coli is cannot easily be detected by physical observation. Dedicated ways used to detect the presence of E-coli are required. The current techniques available are quite bulky in size, also require high expenses and professional training operation. With these limitation, new technique is proposed which are considerably low-cost and user friendly device in detecting presence of E-coli. The fabrication of impedance based sensor using interdigitated electrode (IDE) and Polydimethylsiloxane (PDMS) as sensor package have been done in this study. The impedance response of the proposed sensor have been observed using impedance analyser. Based on the observation, the sensor device able to differentiate the sample's condition tested in frequency of 1000 Hz until 3000 Hz, but no significant changes observed at the higher frequency range. With the initial results obtained, the proposed device was demonstrated being able to distinguish different E-coli concentration