Biosensors for label free detection based on RF and MEMS technology

A bio-detection method and devices based on RF electric signals and MEMS are proposed and demonstrated by a label free method. We have fabricated a transmission line, an inductive device, and a capacitive device with silicon-based MEMS technology. Main issues are fabrication of devices by MEMS technology, surface modification from hydrophobic to hydrophilic of a benzocyclobutene (BCB) layer by plasma radiation and RF signal measurement before and after bio-processing. The devices made by MEMS technology consist of a BCB polymer and Cu metal patterns on a silicon substrate. Glucose oxidase (GOx) and poly dimethyldiallyl ammonium chloride (PDAC) are used as a biomolecule target and probe. The measured output of power loss is 0.8 dB at 1.9 GHz, and its value is pretty distinguishable from the noise level. From the above-mentioned results, it is clear that the proposed RF method and designs are very effective and powerful as a label free detection system.