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Updated: Oct 7, 2025

Fabricating a UV-Vis and Raman Spectroscopy Immunoassay Platform
Published on: November 10, 2016
SERS-Active Composites with Au-Ag Janus Nanoparticles/Perovskite in Immunoassays for Staphylococcus aureus
Yinjuan Xu1, Lixia Shi1, Xiaohui Jing1
1Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, International Joint Research Center for Photoresponsive Molecules and Materials, School of Chemical and Material Engineering, Jiangnan University, Wuxi, Jiangsu 214122, China.
Abstract:
The accurate detection of Staphylococcus aureus enterotoxins (SEs) is vital for food safety owing to their high pathogenicity, which may be performed with surface-enhanced Raman scattering (SERS) if SERS-active nanostructures are used. Herein, a Au-Ag Janus nanoparticle (NPs)/perovskite composite-engineered SERS immunoassay was developed for SEC detection. Plasmonic Au-Ag Janus NPs demonstrated inherent SERS activity from the 2-mercaptobenzoimidazole-5-carboxylic acid ligands. CsPbBr3@mesoporous silica nanomaterials (MSNs) were prepared and transformed into CsPb2Br5@MSNs in the aqueous phase. Paired SEC antibody-antigen-driven plasmonic Au-Ag Janus NP-CsPb2Br5@MSN composites were prepared. They showed amplified SERS activity, attributed to the depressed plasmonic decay due to electromagnetic field enhancement and the electron transfer mechanism. A positive relationship was established between SERS signals of composites and the SEC concentration. An additive-free SERS immunoassay was developed for simple, sensitive, and reproducible SEC detection. This study will be extended to develop multiple additive-free SERS-active plasmonic NP/perovskite composites that will open up the possibility of exploring more SERS detection probes for food safety monitoring.

