on-chip oval-shaped nanocavity photonic crystal waveguide biosensor for detection of foodborne pathogens

A photonic crystal waveguide (pcw) biosensor is proposed for the detection of foodborne pathogens. various semiconductor materials and insulator with higher to lower refractive indices (si, gaas, si3n4, and sio2) are analyzed to fix the choice of material in pcw design. the design and analysis are performed using finite difference time domain (fdtd) simulation method. the design exhibits two inverted j-shaped defects with center cavity designed in the shape of escherichia coli. in this research, dh5α strain of e. coli foodborne pathogens is considered as a model due to its shape. simulation of pcw design is performed using infrared radiation (1 and 1.55 μm) wavelengths. simulation analysis reports larger resonance wavelength shifts, higher sensitivities, and quality factors for si-based pcw biosensor at an operating wavelength of 1.55 μm.