Nanocavity-Coupled Photonic Crystal Waveguide as Highly Sensitive Platform for Cancer Detection

A biosensing platform based on a nanocavity-coupled photonic crystal waveguide (PCW) is proposed for diseased cell detection. The proposed label-free waveguide-cavity-coupled nanostructure with high-Q is designed and analyzed to exhibit high sensitivity and high selectivity against five different cancer cells. The introduction of a nanocavity in the PCW leads to a sharp resonance that makes it useful for the detection of infected cells. It is observed through the 2-D finite-difference time-domain method that the resonant wavelength of a biosensor is red shifted on increasing the refractive index of the nanocavity imposed by the presence of a cancer cell. The reported sensitivity and quality factor of the proposed platform are acceptable for the cell-level detection of various diseases. The proposed design also shows sufficiently separated resonant peaks for different cancer cells that offer us a possibility of highly selective label-free cell-level cancer detection.