Design of a highly sensitive cascaded rectangular ring resonator embedded with gold nanorods and gratings for multipurpose application

This study introduces a sensor consisting of a metal-insulator-metal (MIM) structure, having an integration of gold nanorods and gratings, to perform various functions including sensing refractive index, detecting blood components, monitoring temperature, and measuring magnetic fields. The sensor's spectral properties are studied analytically in the MIR region implementing finite element method. Furthermore, the potential in the RI sensing is extensively examined by modulating the geometrical parameters, ultimately establishing a direct relationship with the transmittance profile. Following computational experiments, the best possible configuration exhibits the maximum sensitivity of 6118.685 nm/RIU. This research shows the biosensing applications by the detection of near-infrared and visible blood components such RBC, Hb, WBC, plasma, and water with a high sensitivity of 3185.05 nm/RIU. Moreover, ethanol is employed to evaluate the proffered sensor's temperature sensing feature and a maximum sensitivity 1.18 nm/°C was attained. Furthermore, this sensor can be used for magnetic field detection as it shows a high magnetic field sensitivity of 354.66 pm/Oe. The structural model is simple. Besides, this design has the potential to serve as a substitute for sensors that rely on silver. It is chemically stable and performs well in refractive index measurement, biosensing, temperature sensing and magnetic field detection.