In this paper, a four open channel dual-core photonic crystal fiber (OC-DC-PCF) refractive index (RI) sensor is numerically investigated by finite element method (FEM) based software for the detection of unknown biomolecules. To create the surface plasmon resonance (SPR) effect, novel plasmonic material gold (Au) is externally deposited to the selected slotted region which makes this design cost-effective. We obtain the maximum wavelength sensitivity (WS) 38000 nm/RIU and the amplitude sensitivity (AS) of 1286 RIU⁻¹ by using wavelength and amplitude interrogation method respectively. The average spectral sensitivity is 6308 nm/RIU. The maximum figure of merit (FOM) of 760 RIU along with the maximum sensor resolution of 2.63×10⁻⁶ RIU is achieved within the analyte RI range of 1.33 to 1.45 for this design which is better than the reported existing works. According to its high sensitivity and cost-effective nature, large detection range, high linearity and FOM, low propagation loss, and low fabrication complexity- it can be an appreciable competitor in the region of bio sensing. The proposed sensor can detect successfully the biomolecules like water, ethanol, fused silica, silicone oil, kerosene, acetone, glucose solution, Teflon, cornea, lens, liver and intestinal mucosa of human etc.

In this paper, we proposed and analyzed a simple circular slotted micro-channel photonic crystal fiber (MC-PCF) based surface plasmon resonance (SPR) sensor. Using finite element method (FEM) the numerical performances are investigated with an external sensing approach. Gold is a chemically stable material that is used in the purpose of plasmonic material at the thickness of 30nm. Simulation results show that the maximum wavelength sensitivity (WS) 25,000 nm/RIU having wavelength resolution (WR) of 4×10⁻⁶ RIU, maximum amplitude sensitivity (AS) is obtained about 1897 RIU^-1 showing amplitude resolution (AR) of 6.25×10⁻⁶ RIU. In addition, figure of merit (FOM) is found about 277.77 RIU^-1 for the analyte refractive index (RI) changes from 1.43-1.44 (RIU). The major nobility is that the proposed sensor shows a broad detection range from 1.33-1.47 RI with the wavelength range from 0.55 to 1.80 µm. Because of the promising sensitivity the proposed model can be applicable for biomolecules and biochemical (i.e., DNA, mRNA, sugar, proteins, carbohydrates, lipids and nucleic acids) sample detection and play the greatest role to detect antibody antigen interaction to find out genome sequences.

An extremely highly sensitive photonic crystal fiber (PCF) based SPR or surface plasmon resonance biosensor is manifested in this article, in a cumulated form of circularly slotted spiral lattice structure (SLS). The numerical performance analysis of the sensor is critically interpreted using the finite element method (FEM), including a perfectly matched layer (PML) and scattering boundary conditions. Very well known chemically stable material gold is used as the plasmonic material and implanted inside the circular slots to lessen the fabrication challenge and oxidation problem. The prospective model shows the maximum value of sensitivity is 41,000 nm/RIU, employing the method of wavelength interrogation and a maximum value of sensitivity of 4242 RIU⁻¹, using the method of amplitude interrogation. The proposed sensor has the capability of detecting analytes in a massive range of the refractive index 1.32 to 1.50 RIU (for wavelength 0.5 µm to 1.55 µm) with a highest sensor resolution of 2.44 × 10⁻⁶ RIU. It is highly capable of identifying biomolecules like benzene, carbon tetrachloride, ethyl alcohol, acetone, water, silicon oil, and glucose solution in water, fused silica, cornea, lens, liver cell, and intestinal mucosa of human, polylactic acid, vegetable oil, and glycerol, etc. The sensor exhibits high linearity by showing R² value 0.97 with a maximum FOM of 683 RIU⁻¹. For large detection range, immense sensitivity, high FOM, and low fabrication complexity, the illustrated sensor can be a supreme candidate in the realm of SPR biosensor.

In this manuscript, an immense sensitive single-core double-slotted square-shaped SPR biosensor externally coated with gold nano films is designed and critically analyzed. The sensor shows a wide range of sensing capacity between 1.41 to 1.49 RIU. Two circular slots are constructed to hold more analytes inside the slots. The sensor shows extremely sensitive behavior with the highest sensitivity of 36000nm/RIU with the maximum amplitude sensitivity of 1380 RIU⁻¹. The maximum resolution of the sensor is 9×10⁻⁵ RIU. The sensor parameters are optimized in COMSOL Multiphysics software by observing fabrication tolerance using percentage variations of parameters. The experimental data of the proposed sensor also shows good polynomial fitting and a high figure of merit (FOM). Because of the newer structure, high sensitivity, large detection range, high stability and high resolution the proposed sensor can be a tough candidate in the realm of bio-sensing and biochemical applications.