Design and Characterization of Impedance based E. Coli Sensor

Foodborne illness has become a concern due to high disease rate and huge losses caused. It is critical to detect and identify the pathogen in food by using sensor. However the conventional methods for pathogen detection are quite time-consuming, costly and label-dependent. This paper presents the design, fabrication and characterization of the impedance based biosensor for the detection of E. coli in water with features of low cost, rapid detection, easy to use and label-free. The interdigital electrodes and microfluidic system based devices were tested in different concentrations of E. coli samples with different structure electrode parameters for sensor characterization. Impedance analyzer was used for monitoring the impedance change to determine the operating frequency. The fabricated interdigital electrodes are also able to discriminate between dry and wet conditions by presenting different impedance outcomes at low frequency. The results depicted in this paper provide a guideline for detection of E. coli contamination level at different concentration with corresponding impedance range.