Designing Highly Sensitive Surface Plasmon Resonance Sensor With Dual Analyte Channels

Md Aslam Mollah,Md Abdul Based,Julfikar Haider,Sivaprakasam Palani,Md Towfik Elahi,Mominul Ahsan,Hasan Sarker

doi:10.1109/access.2021.3118927

Abstract

The ease of controlling waveguide properties through unparalleled design flexibility has made the photonic crystal fiber (PCF) an attractive platform for plasmonic structures. In this work, a dual analyte channel’s highly sensitive PCF bio-sensor is proposed based on surface plasmon resonance (SPR). In the proposed design, surface plasmons (SPs) are excited in the inner flat portion of two rectangular analyte channels where gold (Au) strip is deposited. Thus, the surface roughness that might be generated during metal deposition on circular surface could be effectively reduced. Considering the refractive index (RI) change in the analyte channels, the proposed sensor is designed and fully characterized by the finite element method based COMSOL Multiphysics software. Improved sensing characteristics including wavelength sensitivity (WS) of 186,000 nm/RIU and amplitude sensitivity (AS) of 2,792.97 RIU−1 in the wide RI range of 1.30 to 1.43 is obtained. In addition, the proposed sensor exhibits excellent resolution of $5.38\times {10}^{-7}$ , signal to noise ration (SNR) of 13.44 dB, figure of merits (FOM) of 2188.23, detection limit (DL) of 101.05 nm, and detection accuracy (DA) of 0.0204 nm−1. Outcomes of the analysis indicate that the proposed sensor could be suited for accurate detection of organic chemicals, bio-molecules, and biological analytes.

Highlights

T HE high demand of portable, lightweight, highresolving, and cost-effective devices for bio-sensing application has drawn immense interest in designing miniaturized sensors
In surface plasmon resonance (SPR), an electromagnetic (EM) wave called surface plasmon wave (SPW) is generated at the metal-dielectric interface when the free electrons of the metal become excited by the evanescent wave of p-polarized light
Shuai et al proposed a liquid core photonic crystal fiber (PCF) having an internal circular air hole coated with gold and achieved a negative wavelength sensitivity (WS) of -5500 nm/RIU in the analyte range of 1.50-1.53 [9]

Summary

INTRODUCTION

T HE high demand of portable, lightweight, highresolving, and cost-effective devices for bio-sensing application has drawn immense interest in designing miniaturized sensors. Shuai et al proposed a liquid core PCF having an internal circular air hole coated with gold and achieved a negative wavelength sensitivity (WS) of -5500 nm/RIU in the analyte range of 1.50-1.53 [9]. Gao et al designed a Ge-doped solid silica core PCF having six internal circular air holes coated with thin gold and TiO2 films and obtained WS and amplitude sensitivity (AS) of 2000 nm/RIU and 370 RIU−1, respectively, in the relatively lower analyte range of 1.33 to 1.35 [10]. Rifat et al achieved improved sensitivity (AS and WS of 1,420 RIU−1 and 11,000 nm/RIU, respectively) and wider sensing range (1.33 to 1.42) using only one gold-coated circular air hole [11]. A SPR sensor where the metal deposited internally at the inner flat surface of two analyte channels has been proposed. Before going to investigate the sensor performance, all of the designed parameters are optimized in a systematic way

VARIATION OF GOLD LAYER THICKNESS

VARIATION OF PITCH

PERFORMANCE ANALYSIS WITH NUMERICAL RECORDS

CONCLUSION