Using the near field optical trapping effect of a dielectric metasurface to improve SERS enhancement for virus detection.

ABSTRACT: In this paper, we report the effect of optical trapping on the enhancement factor for Raman spectroscopy, using a dielectric metasurface. It was found that a higher enhancement factor (up to 275%) can be obtained in a substrate immersed in water, where particles are freee to move, compared to a dried substrate, where the particles (radius [Formula: see text] nm, refractive index [Formula: see text]) are fixed on the surface. The highest enhancement is obtained at low concentrations because, this case, the particles are trapped preferentially in the regions of highest electric field (hotspots). For high concentrations, it was observed that the hotspots become saturated with particles and that additional particles are forced to occupy regions of lower field. The dielectric metasurface offers

SUBMITTER: Kenworthy CF 

PROVIDER: S-EPMC7994300 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature