Influence of Plasma Polymerized Dielectric Buffer Layer and Gold Film on the Excitation of Long-Range Surface Plasmon Resonance

Abstract

Recently, long-range surface plasmon resonance (LRSPR) sensor has attracted a great deal of attention as a potentially non-destructive and label-free technique for cellular studies in real time. Thus, much effort has been placed on the fabrication and optimization of multilayered structure required for the excitation of LRSPR. In this work, a detailed study about the influence of both plasma polymerized dielectric buffer layer (DBL) and thin gold film on the excitation of LRSPR was performed. The DBLs of different thicknesses were deposited directly onto SF11 glass slides by radio frequency plasma polymerization (pp) of perfluorooctyl ethylene (PFOE). Thereafter, Au films of different thicknesses were thermally evaporated onto the ppPFOE layers. Atomic force microscopy (AFM) results suggest that the resulting SF11/ ppPFOE/Au structure has a smooth surface regardless of Au film's thickness. LRSPR measurements indicate that the excitation of LRSPR relies not only on the thickness of the ppPFOE buffer layer, but also on the thickness and optical property of thin Au film. Theoretical simulation based on Fresnel's equation allows for the determination of both the thickness and optical constant of each layer supporting the LRSPR, and also enables us to predict the optimum combination of ppPFOE and Au film in a LRSPR sensor. The performance of various LRSPR sensors to monitor the bulk refractive index variation has also been investigated.

Long-range surface plasmon resonance sensor based on side-polished D-shaped hexagonal structure photonic crystal fiber with the buffer layer of magnesium fluoride

“…The important condition for the improvement of the LRSPR sensing properties is that the RI of the DBL is lower than that of a SP PCF, and the degree of RI matching between the DBL and analyte is higher (i.e. the permittivities of the two are closer) [37]. Therefore, a sLRSPR sensor, consisting of the sensing architecture substratum/DBL/metal film/D-BL/analyte, is proposed (figure 1(d)).…”

From Basics to Frontiers: A Comprehensive Review of Plasma-Modified and Plasma-Synthesized Polymer Films

“…Perfluorinated alkenes, e.g., tetrafluoroethylene (TFE) [271] ; Hexafluoropropylene oxide (HFPO) [272] ; Hexafluoropropene (HFP) [273] ; Perfluorooctyl ethylene [274] ; 1H,1H,2H,2H-perfluorooctyl acrylate (PFOA) [275] ; Hexafluoroethane (C2F6) [276] Biocompatible monomers Allylamine [66,277] ; glycidyl methacrylate [243] ; acrylic acid [263,278,279] ; 2-hydroxyethyl methacrylate (HEMA) [280]…”

“…Perfluorooctyl ethylene [273]; 1H,1H,2H,2H-perfluorooctyl acrylate (PFOA) [274]; Hexafluoroethane (C 2 F 6 ) [275] Biocompatible monomers…”

Tantalum Disulfide (TaS2)–Based Symmetrical Long-Range Surface Plasmon Resonance Biosensor with Ultrahigh Imaging Sensitivity and Figure of Merit

“…LRSPR sensor performance is influenced by several parameters, including the kind of substrate, the type and thickness of the metal film, and the degree of RI matching between the DBL and sensing medium. The ease of LRSPR excitation increases with the degree of RI matching between the DBL and sample solution containing analyte [10]. The symmetric coupling or interaction of SPPs at each interface of the metal film produces an evanescent field with higher strength, longer range of propagation, and deeper penetration.…”

“…However, it is unable to analyse multiple biomolecular interactions at a time in prism coupled sensor, which can be resolved by employing intensitybased detection scheme i.e. LRSPR imaging [10]. It works on the principle of measuring spatial shift in reflectance at fixed incident angle after attachment of analyte over sensor surface.…”