Study On Preparation Of ZIF-8@sliver-based SERS Substrate And Detection Of Dye Contaminants

Surface Enhanced Raman Spectroscopy?SERS?technology is an ultra-sensitive detection technology for analytes that has made rapid progress in recent years.It is widely used in the detection of water environment pollutants,life sciences,and chemical sensors.Metal Organic Frameworks?MOFs?are organic-inorganic hybrid materials developed in recent years.They are a new type of porous materials that are connected by metal ion central nodes and organic ligands to form a bone structure.They are used for adsorption,separation and catalysis.ZIF-8?Zeolitic Imidazolate Framework-8?is one of the typical MOF materials.In this thesis,several different composite SERS substrates were prepared,and several organic pollutants rhodamine 6G,crystal violet and malachite green pollutant molecules were detected by SERS.The silver nanowires were synthesized by hydrothermal reduction method,and then the silver nanowires in different proportions were mixed with the ZIF-8 precursor solution,and ZIF-8 was wrapped on the surface of the silver nanowires at room temperature to synthesize Ag NW@ZIF-8 compound SERS substrate.Different content ratios can synthesize ZIF-8 with different densities throughout the silver nanowires.The two typical organic dye pollutant molecules rhodamine 6G and malachite green were tested by SERS,and the lowest detection concentrations were 10^-10 and 10^-9 mol/L respectively.The test of the stability of the material shows that the maximum SERS enhancement effect can be maintained for 20 days,and the material maintained for 30 days still has a good SERS enhancement effect.The test of the repeatability of the material can also obtain satisfactory results.Flower-like ZIF-8 material was synthesized by adding tannic acid to ZIF-8 with different contents,and silver nanoparticles were grown on the surface to synthesize flower-like ZIF-8@Ag NPs composite material.By adding different amounts of ZIF-8 to synthesize flower-like materials with different morphologies,it has been shown that flower-like ZIF-8@Ag NPs-c have the best SERS performance.The lowest detection concentrations for rhodamine 6G,crystal violet and malachite green were 10^-14,10^-13,10^-12 mol/L.Testing the stability of the material shows that the maximum SERS enhancement effect can be maintained for 90 days,and the material maintained for 180 days still has a good SERS enhancement effect,and the repeatability test of the material can also obtain satisfactory results.In this experiment,it provides new ideas for the development of surface-enhanced Raman scattering technology through the synergy of excellent properties by combining silver-based nanomaterials with ZIF-8.