Optical properties of fluidic defect states in one-dimensional graphene-based photonic crystal biosensors: visible and infrared Hall regime sensing

Advances in biotechnology are outpacing studies into the use of graphene in photonic biosensors due to its peculiar optical properties and the successful progress in the nanoscale integration of photonic crystals. Moreover, going beyond the usual Dirac cone approximation for graphene introduces nonlinear effects in graphene’s optics. In this work, by the use of the transfer matrix method, we investigate the effect of hopping parameter on the chemical and biosensing performance of a 1D defective photonic biosensor with a micro/nanofluidic channel as a central defect cavity for biological fluids and gas molecules to flow while interacting with two graphene sheet deposited on silicon dioxide layers of the device. As low-weight molecules absorption on graphene’s surface could affect hopping energy of graphene which plays a significant role in its optical conductivity obtained from the tight-binding model for the visible range, it will serve as a promising tool for the detection of gas and other analytes. We also examine the sensitivity of the defect modes to the changes of the refractive index of the biological fluids under the influence of quantum Hall situation for graphene in terahertz (THz) regime. It is revealed that two defective modes with relatively different sensing properties are emerged within the band stop of the device. The results of this study are not reported elsewhere to the best of our knowledge.