Photonic Crystal–Based Nanoscale Multipurpose Biosensor for Detection of Brain Tumours, HIV, and Anaemia with High Sensitivity

A nanoscale-based 2D-photonic crystal (PhC) biosensor with silicon rods arranged in a triangular lattice structure is proposed in this work. The unique characteristic of the proposed structure is the design of dual nanocavity where two different rod radii are used within the ring resonator. The plane-wave expansion (PWE) method is used to analyse photonic band gaps (PBGs) and the sensing parameters are analysed using finite difference time domain (FDTD) techniques. The proposed biosensor is aimed at detecting the brain tissues, human immune deficiency virus (HIV)–infected blood samples, and sickle cell anaemia. The sensor proved its efficiency in detecting and distinguishing accurately between the brain tissues that are normal and aberrant (tumorourous, malignant, and damaged tissues). The proposed sensor achieves a high-quality factor (QF) of 9867, a high sensitivity of 1105 nm/RIU with an extremely low detection limit (DL) of 0.70 × 10 −5 , towards brain tissue analysis. This sensor can distinguish between a normal blood sample and HIV-infected samples. The QF, sensitivity, and DL of the biosensor for the HIV-infected sample are 2720, 1034 nm/RIU, and 2.61 × 10 −5 RIU respectively. The sensor also proved its efficiency in analysing sickle cell anaemia in the blood sample. The QF and sensitivity of the biosensor are 6428 and 1071 nm/RIU respectively towards anaemia prediction. The proposed nanoscale photonic sensor could be a promising platform for other biomedical applications, such as the detection of various diseases at the cellular level.