Abstract
This paper presents a concept for a passive wireless DNA sensing platform that exploits a multidisciplinary area, synthesizing the conventional DNA capacitive sensing mechanism and the surface-based conformational characterization throughout DNA immobilization and hybridization. The resonant frequency shift, caused by the change of capacitance throughout DNA immobilization and hybridization and occurring on top of an interdigital capacitor, is monitored by means of an impedance analyzer. 32 samples were measured throughout the experiment and the average capacitance measurements represented a variety of surface charges resulting from DNA molecule immobilization and hybridization. The capacitance changed from 11.58 pF to 114.5 pF when specific ssDNA was attached to electrodes and then increased to 218.6 pF once complementary strand DNA was introduced and hybridized with existing DNA chains. In addition, using impedance analyzer measurements, the resonant frequency decreased from 2.01 MHz to 1.97 MHz in the presence of ssDNA and decreased further down to 0.95 MHz after the complementary strand DNA was deposited.