Performance Analysis of Resonance-Based Transducers in Terahertz Bio-Chips Using Equivalent Surface Impedance Model

The concept of equivalent surface impedance is applied for electromagnetic modeling of thin-film samples, e.g., nano-layers of deoxyribonucleic acid, placed on a metallic surface. For the first time, it is shown that by using such a concept, the performance of resonance-based terahertz bio-chips can be easily evaluated in terms of analytic sensitivity and selectivity. Numerical results are presented for the performance of a planar resonator as an example when used as a transducer in a bio-chip sensor. The proposed model is general and can be applied to any resonant transducer with metallic surface for receiving thin-film samples.