Surface-plasmon-enhanced light scattering from microscopic spheres

Abstract

The enhanced light scattering from microscopic latex spheres placed in the optical field associated with a surface-plasmon resonance is explored. Spheres of 200 nm diameter are placed on an optically thin gold film that supports the surface-plasmon and the scattered intensity is then measured as a function of scattering angle. This is compared to the scattering profiles obtained from spheres placed on a bare glass substrate. In both cases, the experimental data are compared to theory. This system is of interest in the field of optical biosensing.

Exploiting Surface-Plasmon-Enhanced Light Scattering for the Design of Ultrasensitive Biosensing Modality

“…23 In addition, the early study by Jory et al demonstrated the possibility of detecting the scattering of latex particles excited by SPs. 24 Recently, the evanescent light scattering has been employed to visualize single surface-bound lipid vesicles without the fluorescent dye labeling. 25 The proposed concept of SP-LS assay builds on these concepts toward the development of an ultrasensitive biosensing scheme, and the excellent sensitivity obtained supports its applications in molecular biosensing, especially for the detection of lowmolecular-weight biomarkers found at low concentration.…”

Distance-controlled scattering in a plasmonic trap

“…Previous studies by a few other groups pointed out that a continuous metallic film can dramatically alter the far field scattering of small particles. Jory et al 9 measured the scattering of microscopic dielectric spheres deposited on a continuous gold film and found that the scattering is remarkably enhanced compared to the situation where the particle is directly deposited on a bare glass substrate. Lévêque et al 10,11 theoretically predicted the distance-dependant plasmon resonant coupling between a gold nanoparticle and a gold film.…”

Plasmon-induced light concentration enhanced imaging visibility as observed by a composite-field microscopy imaging system

“…The plasmon-induced light concentration (PILC) effect, 1 , 2 an opposite phenomenon to the optical invisible cloak 3 , 4 which results from the larger extinction cross sections of plasmonic nanocrystals than their geometrical cross sections, 5 is an effect by which noble metals can unprecedentedly concentrate light into the deep sub-wavelength volumes in close proximity to plasmonic nanoparticles. Enhancement phenomena in nano-optics, including Raman, 6 – 8 fluorescence, 9 light absorption in solar energy harvesting, 10 high-harmonic generation, 11 , 12 and scattered light of dielectric particles, 2 , 13 , 14 have been interpreted as involving the PILC effect. Both localized surface plasmon resonance (LSPR) and PILC disclose the strong electromagnetic field attributed to the extensive interaction between the incident light and plasmonic nanoparticles, 15 , 16 but the former is described mainly in terms of the finite frequency, 17 while the latter is mainly from the perspective of the broad interaction space.…”