Jump to main content
Jump to site search


Multi-branch Au/Ag bimetallic core-shell-satellite nanoparticle as versatile SERS substrate: the effect of Au branches in mesoporous silica interlayer

Abstract

We synthesized a novel bimetallic core-shell-satellite surface-enhanced Raman scattering (SERS) substrate (AuNS@mSiO2@AgNP) that consists of a gold nanostar (AuNS) core, a mesoporous silica (mSiO2) shell and a layer of silver nanospheres (AgNP) satellites. The core-shell-satellite nanostructure was formed by growing branches in the mSiO2 shell of mSiO2 coated gold nanosphere (AuNP@mSiO2), and subsequent deposition of AgNP on the mSiO2 surface. The growth of AuNS in mSiO2 led to the formation of a large number of closely spaced branches which provide enormous hotspots; and by varying the length of the branches, the nanogap distance between the AuNS core and the AgNP satellites can be carefully adjusted. Besides, the mSiO2 could allow the infiltration of analyte into the nanogap area that have high SERS enhancement. To demonstrate the feasibility of the SERS substrate, the bimetallic core-shell-satellite nanostructures were used for the label-free detection of pesticide thiram. The AuNS@mSiO2@AgNP was shown to have excellent selectivity and SERS activity which is significantly higher than AuNS@mSiO2, mSiO2@AgNP and AuNP@mSiO2@AgNP. The method exhibits a good linear response when the thiram concentration ranges from 10-9 M to 10-3 M, and the limit of detection (LOD) is 10-9 M, showing that the bimetallic core-shell-satellite nanostructure is a promising SERS substrate.

Back to tab navigation

Publication details

The article was received on 20 Aug 2017, accepted on 11 Oct 2017 and first published on 12 Oct 2017


Article type: Paper
DOI: 10.1039/C7TC03788K
Citation: J. Mater. Chem. C, 2017, Accepted Manuscript
  •   Request permissions

    Multi-branch Au/Ag bimetallic core-shell-satellite nanoparticle as versatile SERS substrate: the effect of Au branches in mesoporous silica interlayer

    J. Zhao, L. Long, G. Weng, J. Li, J. Zhu and J. Zhao, J. Mater. Chem. C, 2017, Accepted Manuscript , DOI: 10.1039/C7TC03788K

Search articles by author

Spotlight

Advertisements