Multilayer system for a high-precision surface plasmon resonance sensor

Abstract

A multilayer surface plasmon resonance system was designed for high-precision chemical sensor applications. In this sensor, the angular distribution of reflectance from a thin metal film-which is in contact with a sample-is measured. An absorption peak is observed whose angular distribution of reflectance, owing to the excitation of surface plasmon resonance, is measured. The refractive index of the sample is determined from this peak angle. The resolution limit for refractive-index measurements is determined by the absorption peak width. We describe a multilayer system in which an additional layer is added to the conventional Kretschmann geometry; as a result, peak widths are significantly reduced. The angular distribution of reflectance is calculated using Fresnel's formulas and multiple-reflectance theory in order to understand the effect of thickness and refractive index of the additional layer. By optimizing the thickness of the layer, peak widths are reduced to approximately one third of that obtained using the Kretschmann geometry. Experimental results demonstrate the feasibility of this approach.

Effects of intermediate dielectric films on multilayer surface plasmon resonance behavior

“…To analyze the effects of the intermediate dielectric layers on the SPR curves, a simplified model as shown in Fig configuration is characterized by a long-range SPR with a very sharp SPR curve [17,20]. Our results are in good agreement with the reports in the open literature.…”

“…The SPR curve is usually characterized by three major features: the resonant angle h R , the minimum reflectance or resonant depth R min and the width of the resonant curve Áh [17,18]. In biosensor applications of the prism-couplerbased SPR, the analyte under test is placed on the metal interface performing as the second medium of the prism/ metal/analyte configuration.…”

Long Range Surface Plasmons for Observation of Biomolecular Binding Events at Metallic Surfaces

“…LRSPs have a symmetric profile of the magnetic intensity field across the metal layer and exhibit an order of magnitude lower damping compared to conventional SPs [5]. Since the early 1990s, LRSPs have attracted attention for the design of high-resolution SPR sensors [6]. Up to now, LRSP-based sensors were mostly applied for measurements of the RI changes in bulk media [7].…”

Design and Development of Long Range Surface Plasmon Resonance Sensor Chip and System for High Sensitivity Detection

“…Long range surface plasmon resonance (LRSPR) was used to improve the penetration depth, electric field strengths, and the sharpness of angular resonance curves compared with the CSPR. Matsubara et al presented experimental verification of an angle modulated type of an LRSPR-based sensor in 1990 [8]. Recently, LRSPR were introduced to Observe biomolecular binding events at metallic surfaces.…”