Ultrasensitive High Quality Terahertz Biosensor Based on 1D Photonic Crystal for the Detection of Breast Cancer Cells

In this paper, we theoretically investigate the optical properties of defective one-dimensional crystals as a biosensor for the early detection of breast tumors. The theoretical model of defective 1D photonic crystal consists of Si/SiO₂ layers and a defect layer consists of the dispersion of normal breast tissue and breast cancer tissue into the water as analyte material. The effective refractive index of the defect layer is based on the Maxwell–Garnett model at different filling fractions of cancer cells. A transfer matrix method is used to calculate the transmission spectra and other optical properties like sensitivity, Q-factor, and figure of merit in the THz region. Additionally, the detection of cancer cells using a design biosensor is measured by shifting the transmission peak with incident angle, defect layer thickness, and filling fraction concentration of the analyte. The present theoretical design may have potential application as a biosensor to detect breast cancer even with the minimal amount of cancer cells.