Sensitivity enhancement of an impedance-based cellular biosensor by a nanopatterned PEDOT:Nafion interface

A nanopatterned poly(3,4-ethylenedioxythiophene) (PEDOT):Nafion composite layer integrated with interdigitated electrodes was developed to improve the device dynamic range and sensitivity for cellular impedance spectroscopy. The nanopattern fidelity to provide cellular alignment was accessed at different mixing volumes of PEDOT to Nafion. The ion transfer rate and electrical conductivity of Nafion were improved as the mixing ratio of PEDOT increased and it provided a uniform electrical path, thus giving conformable characteristics at all spectral frequencies from 1 kHz to 100 kHz for cellular impedance spectroscopy. Computational modeling was provided to extrapolate the electrical current flow and density in the composite with respect to the different frequency ranges. These results highlight that an electrically modified Nafion nanopattern interface, combined with interdigitated electrodes, can be used for various types of impedance-based cellular biosensors in a more biomimetic and sensitive manner.