A Label-free Protein Sensor Based on Mems Fabry-perot Interferometer Integrated with Silicon Photodiode

ABSTRACT We have newly developed a label-free protein sensor based on MEMS Fabry-Perot interferometer integrated with a photodiode, which utilizes nonlinear optical effect of the Fabry-Perot resonance to enhance the sensitivity of surface stress. A parylene was used for a deformable membrane of the protein sensor because of the high optical transmittance and low Young’s modulus. Theoretical signal-to-noise ratio of the proposed sensor with the surface stress of -0.1 N/m with 200 μm diameter using a light source of 10 mW is calculated 1.55 x 10 with the experimental dark current noise of 10 nA in the photodiode which is two orders of magnitude larger than piezoresistive type. A photocurrent was demonstrated to shift by 23.7 nA at 3 V bias voltage with immobilized antibodies.