A Highly Sensitive Gold-Coated Photonic Crystal Fiber Biosensor Based on Surface Plasmon Resonance

Abstract

Abstract:In this paper, we numerically demonstrate a two-layer circular lattice photonic crystal fiber (PCF) biosensor based on the principle of surface plasmon resonance (SPR). The finite element method (FEM) with circular perfectly matched layer (PML) boundary condition is applied to evaluate the performance of the proposed sensor. A thin gold layer is deposited outside the PCF structure, which acts as the plasmonic material for this design. The sensing layer (analyte) is implemented in the outermost layer, which permits easy and more practical fabrication process compared to analyte is put inside the air holes. It is demonstrated that, at gold layer thickness of 40 nm, the proposed sensor shows maximum sensitivity of 2200 nm/RIU using the wavelength interrogation method in the sensing range between 1.33-1.36. Besides, using an amplitude interrogation method, a maximum sensitivity of 266 RIU −1 and a maximum sensor resolution of 3.75 × 10 −5 RIU are obtained. We also discuss how phase matching points are varied with different fiber parameters. Owing to high sensitivity and simple design, the proposed sensor may find important applications in biochemical and biological analyte detection.

Dual-Core Photonic Crystal Fiber Plasmonic Refractive Index Sensor: A Numerical Analysis

“…6(a) and 6(b), while analyte RI is changed from 1.33 to 1.40. It can be evident from the figure that the amplitude sensitivity increases gradually with an increase in the analyte RI and reaches the maximum for analyte RI of 1.40 which are 554.9 RIU -1 and 636.5 RIU -1 for x-and y-polarized modes, respectively, which are higher than the results reported in [9,17,24,27,28].…”

“…Actually, the resolution is related to the precision of the measurement, but they are not the same thing, and it can be expressed as [29] According to (4), it is clear that the greater the resonance wavelength shift is, the lower the sensor resolution is, hence, the small amount of change in analyte RI can be detected precisely. The maximum sensor resolution of the proposed design is calculated as 1.72 × 10 -5 RIU and 8.7 × 10 -6 RIU for x-and y-polarized modes, respectively for the analyte RI of 1.40, which is higher than the resolution reported in [18,27,28].…”

Single Layer Coating Photonic Crystal Fiber Biosensor based on Surface Plasmon Resonance

“…The most common type ofplasmonic material is being used is Gold because of itsproperties which includes chemically stability, oxidization and it exhibits high sensitivity because of the large resonancepeaks when compared with other plasmonic metals [7].WhenSPR based PCF are compared with fiber-based sensors,theformer provides more sensitivity and resolution whencompared with the latter. Several designs have been proposedby researches in the past few years for different applications.Md Hasan [3] proposed an extremely sensitive PCF basedon Surface Plasmon Resonance which showed wavelengthsensitivity up to 2200nm/RIU 1.33 to 1.36. Azzam [1]proposed a biosensor based on SPR whose sensitivity was 2400nm RIU -1 in visible or near IR region.…”

“…The number of degrees of freedom of a computed mesh generation is 102587 and the number of elements is 19938. The photonic crystal fiber is made up of Silica.The refractive index of the fiber which is made using Silica can be calculated using Sellmeier equation [3] is: Fig. 1.…”

“…B 1 , B 2 , B 3 and c 1 , c 2 , c 3 are Sellmeier coefficients whose values are given by 0.696166300, 0.407942600, 0.897479400 and 4.67914826103 μm 2 ,1.35120631102 μm 2 , 97.9340025 μm 2 respectively. The permittivity of gold is obtained using dielectric function of gold using Drude-Lorentz [3] given as: (2) where the permittivity (ɛ∞) of gold at high frequencies is 5.9673. ω D , γ D , ω,Ω L parameters are explained in [7].…”