Highly sensitive and stable Ag@SiO2 nanocubes for label-free SERS-photoluminescence detection of biomolecules

Spectrochim Acta A Mol Biomol Spectrosc. 2017 Mar 15:175:239-245. doi: 10.1016/j.saa.2016.12.024. Epub 2016 Dec 18.

Abstract

Surface-enhanced Raman scattering (SERS) and fluorescence microscopy are a widely used biological and chemical characterization techniques. However, the peak overlapping in multiplexed experiments and rapid photobleaching of fluorescent organic dyes is still the limitations. When compared to Ag nanocubes (NCs), higher SERS sensitivities can be obtained with thin shelled silica Ag@SiO2 NCs, in contrast metal-enhanced photoluminescence (MEPL) is only found with NCs that have thicker silica shells. A 'dual functionality' represented by the simultaneous strengthening of SERS and MEPL signals can be achieved by mixing Ag@SiO2 NCs, with a silica shell thickness of ~1.5nm and ~4.4nm. This approach allows both the Ag@SiO2 NCs SERS and MEPL sensitivities to be maintained at ~90% after 12weeks of storage. Based on the distinguished detection of creatinine and flavin adenine dinucleotide in the mixture, the integration of SERS and MEPL together on a stable single plasmonic nanoparticle platform offers an opportunity to enhance both biomarker detection sensitivity and specificity.

Keywords: Ag@SiO(2) nanocubes; Biomolecule detection; Dual functionality; Photoluminescence; SERS.

MeSH terms

  • Creatinine / analysis*
  • Flavin-Adenine Dinucleotide / analysis*
  • Luminescent Measurements*
  • Metal Nanoparticles / chemistry*
  • Metal Nanoparticles / ultrastructure
  • Silicon Dioxide / chemistry*
  • Silver / chemistry*
  • Spectrometry, X-Ray Emission
  • Spectrum Analysis, Raman*
  • Staining and Labeling
  • X-Ray Diffraction

Substances

  • Flavin-Adenine Dinucleotide
  • Silver
  • Silicon Dioxide
  • Creatinine