Numerical simulation of the position and orientation effects on the impedance response of nanoelectrode array biosensors to DNA and PNA strands

This paper investigates by simulation the response of a nanoelectrode capacitive biosensor to single and double strands of DNA/PNA and up to frequencies well above the electrolyte dielectric relaxation limit. The expected change in capacitance both for an idealized two electrodes system with 2D cylindrical symmetry and a complex nanoelectrode array, where the biomolecule is represented by a dielectric and charged rod, is calculated for different positions and orientations of the strand. DNA and PNA hybridization is also considered. The results provide indications on optimum detection conditions for admittance based DNA biosensors.