title: Absorption and related optical dispersion effects on the spectral response of a surface plasmon resonance sensor.
abstract: Surface plasmon resonance (SPR) sensing is an optical technique that allows real time detection of small changes in the physical properties, in particular in the refractive index, of a dielectric medium near a metal film surface. One way to increase the SPR signal shift is then to incorporate a substance possessing a strong dispersive refractive index in the range of the plasmon resonance band. In this paper, we investigate the impact of materials possessing a strong dispersive index integrated to the dielectric medium on the SPR reflectivity profile. We present theoretical results based on chromophore absorption spectra and on their associated refractive index obtained from the Lorentz approach and Kramers-Krönig equations. As predicted by the theory, the experimental results show an enhancement of the SPR response, maximized when the chromophore absorption band coincides with the plasmon resonant wavelength. This shows that chromophores labeling can provide a potential way for SPR response enhancement.
authors.affiliation: Laboratoire Charles Fabry de l'Institut d'Optique, Institut d'Optique Graduate School, Univ Paris-Sud, CNRS, Campus Polytechnique, RD 128, 91127 Palaiseau Cedex, France. mohamed.nakkach@u-psud.fr
authors.forename: Mohamed
authors.initials: M
authors.lastname: Nakkach
authors.forename: Pierre
authors.initials: P
authors.lastname: Lecaruyer
authors.forename: Fabrice
authors.initials: F
authors.lastname: Bardin
authors.forename: Jaouhar
authors.initials: J
authors.lastname: Sakly
authors.forename: Zohra
authors.initials: Z
authors.lastname: Ben Lakhdar
authors.forename: Michael
authors.initials: M
authors.lastname: Canva
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D008962:Models, Theoretical; D012031:Refractometry / Q000295:instrumentation* / Q000379:methods; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000295:instrumentation* / Q000379:methods; D014159:Transducers