Substrate with surface-enhanced Raman scattering activity and preparation method thereof

Abstract

The invention provides a substrate with surface-enhanced Raman scattering activity and a preparation method thereof, and the method comprises the following steps: the glass base surface is subjected to hydroxylation and amination treatment; catalytic hydrolysis is carried out on ethyl orthosilicate under the alkali condition by taking alcohol as a solvent; Silica microspheres with even size and smooth surface are prepared by an oscillation method; silane coupling agent of which the tail end is provided with amino is assembled on the surface of the silica microspheres; silver sol obtained by reducing sodium borohydride to silver nitrate through oscillation is assembled on the surface of SiO2-NH2NPs, and is diffused in water again after centrifugal separation and washing by distillated water; self assembly is carried out on the silver sol after being placed in SiO2@Ag NPs dispersion for 6-12h; the SERS active substrate is obtained after taking out from water and drying. In the SERS active substrate of the invention, the active particles and the substrate are combined firmly, thus being applicable to detecting unimolecular Raman signals in aqueous solution; the substrate can be used for SERS detection repeatedly, thus improving repeated utilization ratio of the substrate.

Description

technical field [0001] The invention belongs to the technical field of nanomaterials and laser Raman detection, and in particular relates to a substrate with surface-enhanced Raman scattering activity and a preparation method thereof. Background technique [0002] Surface-enhanced Raman scattering (SERS) is a micro-analysis technique with extremely high sensitivity. detection impact. The precious metals gold, silver, copper and alkali metals have strong Raman enhancement ability, among which silver has the strongest enhancement ability, followed by gold and copper. To obtain the SERS signal, the preparation of the substrate is the premise, so the preparation of a uniform and stable SERS active substrate has become a hot research topic for many researchers. [0003] At present, there are three kinds of active substrates commonly used in SERS analysis: (1) electrochemically roughened noble metal electrodes; (2) vacuum-evaporated metal island films; (3) noble metal sols. Sin...

AI Technical Summary

Problems solved by technology

Martin et al. (Martin S., Seung J.L., Shannon W.B., et al. Adv. Mater, 2006, 18, 2829-2832.) prepared silica nanorods with a regular structure using the PAO template method. The ends are all deposited with silver, and the nanorods with silver ends are transferred to the silicon substrate, so that the end with silver faces upward, so that the surface of the substrate forms a patchwork rough structure, which can be used for surface-enhanced Raman detection, and A good enhancement effect has been obtained, but the preparation method of this SERS active substrate is too complicated

Maurizio (Maurizio M..J.Raman Spectrosc, 2002, 33, 295-297.) reduced silver on the surface of silica nanoparticles by photoreduction. This process was completed in aqueous solution, and compared with traditional silver sol The Raman enhancement effect was compared, and the results showed that the enhancement ability of the composite particles was stronger, but the SERS active material prepared in this way was easy to fall off from the substrate, and the reusability was not good.

Images