Design and Simulation of the Organic Bio-FET for Detection of Escherichia Coli Using Pentacene Organic Semiconductor

A biosensor for the detection of E. coli O157: H7 bacterium has been designed by using the mean of an organic field effect transistor, and the behavior of the sensor was studied and analyzed under a simulated environment. The design of biosensor includes two essential parts: scheming the structure and choosing the material. In the structure part, an OCMFET configuration, previously used for DNA hybridization, for the first time has been employed for the detection of E. coli with some modifications. In the modified structure, a microfluidic pathway has been added to let the analyte in and out, which makes it possible to detect low volumes of the bacterium in the stream of analyte efficiently and quickly. For the material part, Pentacene, as an organic semiconductor, has been used due to its valuable parameters such as environmental compatibility, cheapness, and easy manufacturing processes. The simulation results are shown 2 minutes after applying the analyte, containing 100 CFU/mL E. coli, 35 bacteria adhere to the active area of the device, leading to a 72 mV shift in the I-V curve. This shift reaches about 174 mV for 86 contained bacteria within 5 minutes which indicates high sensitivity of the sensor. The fast response time, notable sensitivity, biocompatibility, fabricability with current technology, and affordability are among the other benefits of this structure.