Copper-based surface plasmon coupled emission steering for biosensor applications

Abstract

Surface plasmon coupled emission (PCE) was demonstrated using Copper (Cu) as metal film and Rhodamine B (RhB) dye doped Poly Vinyl Alcohol (PVA) as dielectric layer coupled to a hemicylindrical prism in Reverse Kretschmann (RK) configuration. Emission directionality was observed due to PCE and the dielectric layer thicknesses highly influence PCE emission steering. A correlation of emission directionality and the dielectric layer thickness was achieved. For dielectric with higher thicknesses, PCE tuning was also observed apart from emission steering. Emission steering and a promising PCE tuning in Cu could pave the way for a cost effective PCE based bio-chemical sensor.

Surface Plasmon-Coupled Directional Emission Enhanced Raman Scattering Based on Waveguide Coupling Surface Plasmon Resonance Configuration

“…29 Compared to normal spectral radiation, SPCE displays unique characteristics such as high directionality, P-polarization, wavelength resolution, and distance dependence, which can more effectively enhance the collection efficiency, detection sensitivity, and interface selectivity of the signals, thereby attracting increasing attention. 27,30 SPCE has been applied in numerous fields, including phosphorescence detection, 31 chemiluminescence, 32 biochemical sensing, 21,33,34 and fluorescence imaging, 21,35−37 becoming a pioneering tool for fluorescence detection, capable of improving the fluorescence detection sensitivity. 26,27,38,39 However, despite being a widely applicable radiative coupling strategy, SPCE is underutilized in the field of Raman scattering.…”

“…To improve the collection efficiency of SERS signals, various approaches such as waveguides, gratings, and plasmonic antennas have been designed, developed, and optimized to concentrate Raman scattering at small divergent angles, thereby achieving high collection efficiency. − However, the complexity of the fabrication processes for gratings and antennas limits their practical applications. In contrast to methods like gratings and plasmonic antennas that enhance SERS collection efficiency, prism-coupled surface plasmon-coupled directional emission offers a simpler solution for efficient SERS collection. − …”

“…This is due to the physical constraint that only specific directions and polarizations of electromagnetic waves can excite surface plasmons on the surface of a metal film . Compared to normal spectral radiation, SPCE displays unique characteristics such as high directionality, P-polarization, wavelength resolution, and distance dependence, which can more effectively enhance the collection efficiency, detection sensitivity, and interface selectivity of the signals, thereby attracting increasing attention. , SPCE has been applied in numerous fields, including phosphorescence detection, chemiluminescence, biochemical sensing, ,, and fluorescence imaging, ,− becoming a pioneering tool for fluorescence detection, capable of improving the fluorescence detection sensitivity. ,,, However, despite being a widely applicable radiative coupling strategy, SPCE is underutilized in the field of Raman scattering. − Previous research has mostly focused on exciting surface plasmon-coupled directional emission Raman (SPCR) on traditional surface plasmon resonance (SPR) structures. , These studies either only utilized the PSPs on continuous silver film surfaces to enhance SERS signals or employed the localized surface plasmons (LSPs) excited by AgNps on inverted SPR structures to enhance SERS signals. However, these studies lacked coupling between PSPs and LSPs, resulting in a poor electric field enhancement effect and limited enhancement of SERS signals.…”