Carbon-nanotube-resonator-based biosensors

A study was conducted to demonstrate carbon nanotube (CNT) resonator-based biosensors, using the biotin-streptavidin system. The CNT resonators were fabricated by connecting the interdigital capacitor to the CNT in parallel. It was found that these CNT resonators exhibited a clear resonance at approximately 10-13 GHz, depending on the device. The resonator frequency was lowered by approximately 0.7-1.3 GHz and the Q factor was enhanced, after the streptavidin was bound to the biotinylated CNT. The resonance frequency shift and the enhanced Q factor were explained by the increase in C_CNT and R _f, according to the simulation results. The resonance frequency measurements and their sensitivity was not reduced for devices with metallic and semiconducting CNTs, as the CNT resonator-based biosensors can detect biomolecules by measuring the capacitance change through the resonance frequency measurements.