D-Shaped Microfluidic Channel Bimetallic with a Highly Sensitive SPR RI Sensor for a Large Detection Range

AbstractA highly sensitive D-shaped microfluidic channel (MFC) incorporated in a single-mode fiber (SMF) equipped with a tungsten trioxide (\(WO_{3}\)) layer coated with gold (Au) or silver (Ag) on the base of the MFC is designed and investigated utilizing a finite element method (FEM) to obtain the sensing performance of the optical fiber surface plasmon resonance (SPR) structure. The proposed sensor is appropriate for both bimetallic layers and analytes. With the sizeable cladding diameter of SMF, the fluidic channel size can be changed following demand, making fabrication more accessible and applicable. The hollow D-section above the core deposited a bimetallic structure of silver (Ag) or gold (Au) as plasmonic materials, followed by a tungsten trioxide (\(WO_{3}\)) nanolayer. This optical fiber biochemical monitors the changes in the refractive index (RI) by measuring the transmission spectral shifts of the fiber at their resonance wavelengths. The\(WO_{3}\) layer protects the plasmonic material from oxidation and effectively enhances the surface plasmon wave (SPW) while interacting with free electrons. Upon achieving the optimum structural parameters, the numerical investigation results showed that the maximum wavelength sensitivity of 6.0\(\mu\)m//RIU and 5.0\(\mu\)m//RIU for Au/\(WO_{3}\) and Ag/\(WO_{3}\) were obtained, with the coefficient of performance of 50.12\(RIU^{-1}\) and 134.84\(RIU^{-1}\), respectively, for ultra-wide sensing ranges from 1.28 to 1.38. Also, ...
Source: Plasmonics - Category: Biomedical Science Source Type: research