Silver Nanoparticle-Decorated Silica Nanospheres and Arrays as Potential Substrates for Surface-Enhanced Raman Scattering

Junfang Li; Yanfang Xu; Lulu Tian; Yibo Yan; Liyong Niu; Xiaohong Li; Zhijun Zhang

doi:10.1021/acsomega.1c04874

Silver Nanoparticle-Decorated Silica Nanospheres and Arrays as Potential Substrates for Surface-Enhanced Raman Scattering

ACS Omega. 2021 Nov 29;6(48):32879-32887. doi: 10.1021/acsomega.1c04874. eCollection 2021 Dec 7.

Authors

Junfang Li¹, Yanfang Xu¹, Lulu Tian¹, Yibo Yan¹, Liyong Niu^{1

2}, Xiaohong Li^{1

2}, Zhijun Zhang^{1

2}

Affiliations

¹ Engineering Research Center for Nanomaterials, Henan University, Kaifeng 475004, P. R. China.
² Engineering Research Center for Nanomaterials Co. Ltd., Henan University, Jiyuan 459000, P. R. China.

Abstract

Poly(vinylpyrrolidone) (PVP) was used as both a modifier and reductant to in situ deposit silver nanoparticles (denoted Ag NPs) on the surface of silica nanospheres (nanosilica or nano-SiO₂), affording Ag-decorated nanosilica (denoted SiO₂@Ag). The as-obtained SiO₂@Ag composite can form silver nanoparticle-decorated silica nanosphere arrays (denoted SiO₂@Ag arrays) via evaporation-induced self-assembly. The as-prepared SiO₂@Ag composite and SiO₂@Ag array were used as the SERS substrates to measure the Raman signals of the dilute solutions of rhodamine 6G (denoted R6G), an organic dye that is a potential pollutant to the environment. The findings indicate that the as-prepared SiO₂@Ag composite and SiO₂@Ag array as potential SERS substrates simultaneously exhibit a high degree of metal coverage and small size of Ag NPs as well as good stability and abundant "hot spots", which contributes to their desired Raman enhancement capacities. For the detection of trace R6G, they provide a limit of detection of as low as 10^-9-10^-11 M as well as good reproducibility, showing promising potential for monitoring chemical and biological molecules.