Investigations On Device Structure and Sensing Mechanism Using Gold Nanoparticles Decorated Photonic Crystal Fiber-based Biosensors

A modified photonic crystal fiber (PCF) was utilized as a biosensor, incorporating gold nanoparticles as an active plasmonic material. The finite element method (FEM) was employed to compute numerical interpretations of sensing performance using various liquids: liver blood, colon blood, human plasma, water, and pentanol. In the proposed biosensor configuration, the test sample (analyte) was placed within the core, surrounded by cladding air holes, and external to the hollow core fiber structure. Sensitivity calculations were conducted both before and after the addition of the gold overlayer. The maximum amplitude sensitivity was determined to be 769.57 RIU^-1 for human plasma, accompanied by the optimal electric field of 400V/m. Similarly, in the same liquid, when the deposited photonic crystal fiber (PCF) was coated with a gold layer, the maximum amplitude sensitivity reached 975.53 RIU^-1 at an optimal electric field of 477 V/m. Considering the proposed sensor as a refractive index sensor, it exclusively utilized an analyte sample within the core and air holes of the PCF. Here, the maximum amplitude sensitivity attained was 869.84 RIU^-1, aligning with the best electric field value of 434 V/m."