Label-Free cancer cell biosensor based on photonic crystal ring resonator

A photonic crystal (PhC) biosensor is a compact device, which detects the changes of characteristic of the light due to binding the sample by the analyte. In this paper; we propose using ring resonator in two-dimensional (2D) photonic crystal biosensor. A periodic array of silicon rods with the refractive index of n = 3.46 in the air bacground formed a cubic lattice structure. The sensing mechanism occures when the the resonant wavelength shifts due to change in the the refractive index of analytes. The transmission spectrum shifts about 4.47 nm to the higher wavelengths by increasing the refractive index of analyte. This mechanism can recognize the normal, and cancerous cells. The average values of sensitivity, quality factor, FOM, and transmission for the designed structure are 308.5 (nm/RIU), 3803.55, 848.06 RIU-1 and 98.78 %, respectively. The reported structure has high quality promising applications for highly sensitive label-free optical biosensors.