U-Grooved Selectively Coated and Highly Sensitive PCF-SPR Sensor for Broad Range Analyte RI Detection

Abstract

Point-of-care (POC) diagnostic medical devices require simple but sensitive and inclusive detection capabilities. This study develops a unique photonic crystal fiber-based surface plasmon resonance (PCF-SPR) sensor that uses a u-grooved selective coating for extremely sensitive remote and biosensing applications. Scale-down (SCD) air holes control the path that incoming light takes through the sensor in order to activate the free electrons that are present there. To reduce outward radiation, perfectly matched layers (PML) of the absorbing boundary are integrated in addition to optimizing the structural geometry and material thickness. The Finite Element Method (FEM) is employed to quantitatively tune the properties of light and sensitivity of the proposed sensor. The proposed sensor has the maximum amplitude sensitivity (AS) of 1189 RIU−1, the highest wavelength sensitivity (WS) of 12,500 nm/RIU, and an outstanding resolution of $8.0\times 10 ^{-6}$ RIU. The constructed model covers a large refractive index (RI) range of unknown samples, ranging from 1.29 to 1.40. This range allows the proposed sensor to cover the detection of a wide range of bio-analytics, including viruses, cancer cells, carbohydrates, proteins, and DNA/RNA, etc. We strongly believe that the proposed sensor will play an extremely useful role in the detection of POC bio-sample detection.

Keywords

• PCF
• sensitivity
• resolution
• SPR
• refractive index
• COMSOL multiphysics