Biofilm detection by the impedance method

The impedance method was used to detect bacterial layer on the surface of micro-electrodes. The interdigital electrodes arrangement was simulated by FEM to determine the detection distance of the sensor. Then, the KB-12 sensor with spacing 15 μm was selected as the most suitable sensor. For experiments, Escherichia coli was chosen as a typical representative of a biofilm creating bacterium and the bacterial growth was measured during 12 hour intervals. The impedance of the sensor KB-12 was changed by 10 percent when covered with a layer of bacteria.