| The discharge of organic dye residues into the water body will seriously damage the ecological environment of the water body and even affect human health.Therefore,effective detection of dye residues in water has become a very important issue.Surface Enhanced Raman Scattering(SERS)technology is widely used in many fields because of its convenience,efficiency,lossless,and high sensitivity.However,the effect of SERS technology largely depends on the nature of the substrate.Commonly used noble metal substrates have poor stability and cannot achieve specific detection.They need to be combined with other substances to improve the properties of the substrate.Molecular imprinting technology can achieve specific adsorption of template molecules.The combination of molecular imprinting technology and SERS can achieve specific and highly sensitive detection of target molecules,which has become an important means of analysis and detection.At the same time,dummy molecular imprinting technology can solve the problem that template molecules are difficult to wash off,and further improve the accuracy of detection.In this thesis,silver nanoparticles with a particle size of 100 nm and 10-20 nm were prepared using ascorbic acid and sodium borohydride as reducing agents,and they were combined with graphene oxide(GO).Three different types of GO/AgNPs were synthesized by self-assembly and in-situ reduction methods.Among them,the lowest detection concentration for crystal violet is 1×10-8 mol/L,and the lowest detection concentration for malachite green is 1×10-7 mol/L.Using the complex as the substrate,crystal violet as the template molecule,and rosin acid as the virtual template molecule,molecular imprinting polymers(MIPs)and dummy molecular imprinting polymers(DMIPs)were synthesized.The results show that the lowest detection concentration of GO/Ag-MIPs for crystal violet is 1×10-12 mol/L,the lowest detection concentration of GO/Ag-DMIPs for crystal violet is 1×10-11 mol/L,which is far better than GO/AgNPs.Both composite substrates have a certain degree of reusability.When detecting crystal violet,they both show good selectivity to crystal violet.And there is a good linear relationship between the intensity of Raman characteristic peaks and concentration of the crystal violet.And the two substrates performed well in the detection of actual water samples,which proves that the detection method proposed in this paper has certain practical application value.The research on the reinforcement mechanism of the composite substrate shows that the reinforcement effect is the result of a combination of many factors. |
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