Minimization of electrode polarization effect by nanogap electrodes for biosensor applications

Nanogap electrodes-based dielectric spectroscopy is introduced to create ultrasensitive biomolecular sensors by minimizing the effects of electrode polarization. The electrode polarization is a major source of error in determining the impedance of biological samples in solution. The unwanted double layer impedance due to the electrode polarization impedance is caused by the accumulation of ions on the surface of electrode. This effect becomes more dominant in low frequency region (< 1 kHz). In this paper we describe nanogap electrodes-based biomolecular measurements that can minimize electrode polarization effects since the double layers overlap and potential drop inside of the electrode gap can be reduced in nanoscale (<100 nm) electrode spacing.