Format of Original
Institute of Electrical and Electronics Engineers
2012 IEEE Sensors Proceedings
Original Item ID
This work presents a cantilever-based mass-sensitive microsensor platform for the detection of biomolecules in the liquid phase. The resonant microstructures feature integrated thermal excitation and piezoresistive detection elements to excite and sense the structure's fundamental in-plane flexural mode. A gold film on the cantilevers allows for the local immobilization of biomolecules using gold-thiol chemistry. Using the in-plane flexural mode, quality factors of the order of 30-50 are obtained in water at resonance frequencies around 500 kHz. The reduced liquid damping enables closed-loop operation of the resonators with frequency stabilities in the ppm-range. Using a microfabricated flow cell, anti-IgG is detected in PBS with limits of detection on the order of 50 ng/ml.