A dual-mode graphene-based optical sensor with high sensitivity for cancer-cell detection

In this paper, we present a graphene-based band-pass filter featuring rectangular-shaped resonators, based on research into the sensing characteristics of surface plasmon polaritons (SPP). The finite-difference time-domain (FDTD) method and simulations reveal that the transmission spectrum of this structure exhibits a dual-mode spectrum. This structure operates at two functional modes with wavelengths of 1135 nm and 1705 nm, and its compact size measures 330 nm × 480 nm. We investigated the effect of geometric parameters on the pass bands, finding transmission rates as high as 0.97 and 0.88, sensitivities of 2166.6 nm/RIU and 2000 nm/RIU, and figures of merit (FOM) of 50.38 and 38.46 RIU⁻¹. Due to the minimal difference in the RI of cancer cells and the high sensitivity of the sensor, it is highly effective for cancer cell detection. Additionally, the accuracy of the sensor's performance is validated using a one-sample T-test, which confirms the precision and reliability of the designed sensor.