Tetra-core surface plasmon resonance based biosensor for alcohol sensing

A novel tetra core surface plasmon resonance (T-SPR) based photonic crystal fiber (PCF) biosensor is proposed for alcohol sensing and detection in near IR region. Alcohol compounds are commercial products and heavily used for different purposes. In this work, different groups of alcohol series like-methanol, ethanol, propanol, butanol, pentanol, and phenol. Therefore, the entire analysis is done by a full vectorial finite element method (FV-FEM) for 1.5-3.0 mu m wavelength. In fact, we use chemically inert plasmonic material as-gold (Au) that helps to obtain maximum sensitivity and provide evanescent field and fused silica is used as the base material. Furthermore, an anisotropic perfectly matched layer (A-PML) is attached for declining nonphysical unwanted radiation conducted as absorbing boundary condition (ABC). The performances values of wavelength sensitivity, resolution and transmittance variance are reported as 40000 nm/RIU, 8.0x10(-3) RIU and 1000 dB/RIU, respectively. In summary, the proposed T-SPR PCF can be widely applicable in fields of bio-optics and can prove it a tough competitor by its sensing performance.