DNA sensing using split-ring resonator alone at microwave regime

In this paper, the feasibility of utilization of a single element double split-ring resonator as a biosensing device has been demonstrated. The compact resonator has been excited by time-varying magnetic fields generated from the 50 Omega microstrip transmission line. In this work, DNA hybridization is recognized with shift in S-21 resonant frequency. When thiol-linked single stranded-DNA is immobilized onto a gold (Au) surface and is then coupled with complementary-DNA, the frequency changes by Delta integral(ss-DNA)=20 MHz and Delta integral(hybridization)=60 MHz, respectively. Thus, it is clear that the resonator can be utilized as a DNA sensing element in the microwave regime. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3459877]