The Analysis And Application Of Flexible Surface Enhanced Raman Scattering Substrate In The Environmental Monitoring

China is a large agricultural country. Pesticide usage which agricultural depends on survival has been high. However, due to the incomplete knowledge of the use of pesticides and its management is not perfect, making the current situation of the use of pesticides is not good, and excessive pesticide residues on food surface is common occurrence. All along, lacking of a powerful method of analysis and testing of surface contaminants thus the enables the detection of surface pesticide residues to be restricted. In this work, we report a ex-site method for fabrication of a SERS substrate which having a g for surface gel mobility and used in analysis pesticide residues on the surface of fruits and vegetables.Firstly, we rely on the Poly(vinyl alcohol)(PVA) hydrogel preparation technology and composite materials synthesized sliver nanomaterials technology. the Ag nanoparticles modified by graphene oxide by electrostatic adsorption. And we concluded that the best protocol is:by microwave irradiation using synthesized Ag colloidal, A GO/PDDA/10 mM Ag NPs suspension was first prepared and used as the solvent for dissolving 8% PVA. And then the PVA-Ag NPs mixture mixed with 4% borax (w/w) at 10:3 ratio (v/v).Then, the flexible SERS substrates were tested for its performance. We found that the limit of detection(LOD) for triazophos is 3.15pg per～cm2 on glass. RSD between each substrate is 23.3%, the same substrate RSD at 10 different locations is 15%～30%, storage period about 5 days. In addition, the substrate is not affected by the roughness of the surface to be measured, but the physical and chemical properties of the surface to be measured are greatly influenced. And this substrate be able to detect other pesticides, such as methyl parathion, quinalphos.Finally, the flexible SERS substrate was used to test the pesticide residues on real world surface. Simply by applying the hydrogel SERS substrate on the surface of interest, limit of quantification for triazophos on the surface of apple, hairy gourd was found to be below the national standard level. In addition, we establish triazophos HPLC standard curve, respectively test the recovery of the surface of apple, hairy gourd. The results show that:the recovery of the glass surface about 55%, the apples surface recovery was 27%, the hairy gourd surface recovery was 16%. Compared to most adapted to the SERS substrate surface analysis, and it has a higher recovery practicality.