Surface Plasmon Resonance Enhanced Transmission of Light through Gold-Coated Diffraction Gratings

Abstract

Narrow peaks are observed in the transmission spectra of p-polarized light passing through a thin gold film that is coated on the surface of a transparent diffraction grating. The spectral position and intensity of these peaks can be tuned over a wide range of wavelengths by simple rotation of the grating. The wavelengths where these transmission peaks are observed correspond to conditions where surface plasmon resonance occurs at the gold−air interface. Light diffracted by the grating couples with surface plasmons in the metal film to satisfy the resonant condition, resulting in enhanced light transmission through the film. Notably, this phenomenon is not observed at flat, gold-coated surfaces or uncoated gratings, where coupling to surface plasmons does not occur. The nature of the coupling and, thus, the details of light transmission are governed by the momentum matching conditions between the diffracted light and the surface plasmons. In the presence of bound analytes or surface films, the enhanced transmission peaks are red-shifted, making a simple, yet highly responsive sensing platform. The utility of this platform is demonstrated for ex situ sensing by analyzing thin films of various thicknesses and detecting a model immunoreaction between bovine serum albumin and anti-bovine serum albumin. This grating-based transmission surface plasmonic device represents a simple and sensitive platform, which can be readily tuned to enhance performance and be used in the study of a variety of surface adsorption processes or analysis of biomolecular interactions.

Wavelength Tunable Surface Plasmon Resonance-Enhanced Optical Transmission Through a Chirped Diffraction Grating

“…[8][9][10][11] Nanostructurebased plasmonic sensing has been achieved with nanohole arrays, 12,13 single nanometric holes, 14 nanoslit arrays, 15 and various grating-type and diffractive nanostructures. [16][17][18][19][20] The construction of nanostructured optical elements for plasmonic sensing can be achieved with a variety of processing techniques. 8 In addition to traditional top-down lithography methods, electron beam lithography and focused ion beam machining have been used to construct ordered and complex nanostructures.…”

“…20 This enhancement consisted of narrow peaks in the visible spectrum, whose central wavelength could be tuned by simple rotation of the grating. This surface plasmon-enhanced transmission resulted in a surface that was highly sensitive to the local refractive index near the gold interface and, thus, could be used in optical sensing applications.…”

“…Measurement of the thickness of several alkane-thiolate monomolecular thin films and detection of the formation of an antigen-antibody complex of BSA-antiBSA were demonstrated using this sensing method. 20 In the work described here, enhanced optical transmission is demonstrated using a grating with a chirped surface profile. We constructed chirped gratings using a technique based upon the surface buckling that occurs following oxidation of elastomeric films such as poly(dimethylsiloxane) PDMS.…”

Enhancing one dimensional sensitivity with plasmonic coupling

“…Since structures can be tuned to excite plasmons when very specific conditions are met, one common use of plasmons is for nanoscale sensing of biological materials [1], [2]. Plasmons have also been used as sensors for material properties [3][4][5], as part of an alternative lithography method [6], and to boost performance of existing devices [7], [8].…”

Surface-enhanced Raman scattering and Plasmon effect for enzymatic bionanocomplexes characterization

“…In presented work two kind of substrates were emplyed to obtained the plasmon effect: the gold nanoparticles (AuNPs) and polycarbonate gratings coated with gold, as a promising plasmonic materials [5,10]. The ChOX-AuNP bionanocomplex was situated on the grating which have improved optical properties and enhance the SERS effect additionally.…”