SERS Based On Silver Nanoflower Silica Core-Shell Structure

Environmental pollution is a hot topic of concern today.Surface-Enhanced Raman Scattering?SERS?is an analytical and detection method with high resolution and high detection sensitivity.It exhibits excellent organic pollutants.Detection performance.The performance of SERS-enhanced substrate preparation is a hot research topic.Gold,silver and copper precious metals are the most commonly used materials for making SERS-reinforced substrates.Silver is the best material for enhancement,but its morphology control is difficult and chemically active and easy to oxidize.Such serious shortcomings greatly limit its practical application.In order to further enhance the detection ability of Ag substrate,the core-shell structure of Ag nanoflowers and SiO₂ is used as SERS substrate,and to overcome the problem of poor stability caused by oxidation of Ag substrate.Finally,it is concluded that the properties of the SERS substrate prepared in this paper have been significantly improved,especially the oxidation resistance of the sample.In this paper,firstly,surface enhanced Raman effect?SERS?and its origin and related theories are introduced.A series of silver nanoparticles with different shell thicknesses @SiO₂ nanoparticles are prepared by classical hydrothermal method and the method summarized by Professor Han Mingyong of Singapore Institute of Materials in his review.The effects of different thickness of SiO₂ on SERS intensity are also studied.The stability of Ag@SiO₂ and its application to the detection of Rhodamine 6G were also discussed.The main contents of this paper are as follows:1.Silver nanoparticles with average particle size of about 300 nm were prepared by reducing silver nitrate with sodium citrate.The nanoparticles were characterized by ultraviolet-visible absorption spectrometer,field emission scanning electron microscopy,Raman spectrometer and transmission electron microscopy.2.Using the classical hydrothermal method and the method summarized by Professor Han Mingyong of Singapore Institute of Materials in his review,several silver nanoparticles with different shell thicknesses@SiO₂ were prepared using tetraethyl orthosilicate as silicon source.3.Using Rhodamine 6G as probe molecule,the enhancement effect of the prepared substrate on Raman signal was tested,and the effect of different thickness of SiO₂ shell on SERS effect was discussed.4.Compared with the stability of silver nanoflowers,it is proved that silver nanoflowers have excellent antioxidant properties in the air.After 35 days of direct placement in the air,they can still be used as a qualified SERS substrate.Figur[21]table[3]reference[58]...