Design and Analysis of a PCF SPR biosensor for Glucose Concentration in Urine Employing External Sensing

Abstract

This research presents a surface plasmon sensor utilizing photonic crystal fiber (PCF), aiming to measure glucose concentrations in urine. The sensor employs a configuration involving TiO2 and gold as plasmonic materials, layered strategically to enhance its performance. Employing a finite element approach, the proposed sensor's simulation focuses on measuring urine glucose levels. The setup involves coating a thin analyte layer onto the TiO2 layer of the PCF, enabling external sensing capabilities. Sensing capabilities are tested across four distinct glucose concentration levels: 0gm/dL, 2.5gm/dL, 5gm/dL, 10gm/dL, and 20gm/dL equating to refractive indices (RI) of 1.335, 1.338, 1.341, 1.346, and 1.358, respectively. A perfectly matched layer (PML) acts as the boundary condition for the topmost PCF layer. Through variations in geometrical parameters, an optimized structural design is achieved, resulting in a wavelength sensitivity of 3825.61 nm/RIU and an amplitude sensitivity of 438 RIU−1 for 2.5 gm/dL. Experimental validation using various urine samples highlights superior accuracy and sensitivity compared to existing methods.