A Highly Sensitive Optical Biosensor with Tunable Point Defect Cavity for Point-of-Care Testing

This paper introduces a surface stress-based BioMEMS sensor featuring an optomechanical detection system designed to measure the target bioparticles' concentration. The sensor incorporates a defective 2D photonic crystal along with a MEMS transducer. When the target bioparticles are absorbed by the bioreceptors immobilized on the sensing area, they induce deformation in the MEMS transducer, which alters the defect structure of the photonic crystal and changes its transmission spectrum. This modification facilitates the precise measurement of the target bioparticles' concentration. Both numerical and analytical analyses were conducted to evaluate the device's performance. The functional characteristics of the proposed device suggest its suitability for near-patient testing applications.