Feasibility study of using two types of microstripline bandpass filters for the detection of bacteria in water

Numerical computation is utilized to evaluate the feasibility of using microstripline bandpass filter circuits as a biosensor for the rapid detection of bacteria in water. The biosensor is based on a change in response of the bandpass filters when bacteria adhering to the surface of the biosensor cause a change in the relative permittivity immediately above the filter. Numerical computations performed using the software packages ADS (advanced design system) and Sonnet on coupled line and hairpin bandpass filter microstripline circuits showed that although both filters responded to the dielectric overlay immediately above the filter, the sensitivity of the latter was greater, making it a better candidate for use as a biosensor for bacteria in water. Computed as well as experimental results are presented and discussed.