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Theoretical Study Of Surface Enhanced Raman Spectroscopy Of Three Amide Insecticides

Posted on:2020-12-28Degree:MasterType:Thesis
Country:ChinaCandidate:S B JiaFull Text:PDF
GTID:2431330575986579Subject:Biochemistry and Molecular Biology
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Surface-enhanced Raman scattering(SERS)is a detection technique that based on Raman scattering by adsorbing molecules or plasma on rough metal surfaces.The spectrum can provide important information such as the structural configuration,orientation conformation,molecular adsorption behavior and the sample molecule adsorption site.The graph has a narrow peak shape?high resolution?good selection and a fingerprint effect on the SERS spectrum.But some pesticides applied to crops are attached to crops,some are scattered in the environment of soil,atmosphere and water,and some of the pesticides left in the environment are absorbed by plants.The residual pesticide directly reaches the human or animal body through the fruit of the plant or water or the atmosphere,and transmitted to humans and animals through the environment and the food chain,endangering the life and health of humans and animals.Bistrifluron,carbaryl,and triflumuron are three common amide insecticides that can be used as controlling lepidopteran pest on a variety of plants such as vegetables,tea,and cotton.In this paper,using the density functional theory(DFT)and with the B3 LYP method to calculate the structure and vibration frequency.For C,H,N,O,F,and Cl atoms,use 6-31++g(d,p)base group,the Ag atom uses the lanthanide group Lanl2 dz,which is a basis group often used for calculation of transitional heavy metal atom systems.The highest occupied orbital(HOMO)energy value and the lowest occupied orbital(LUMO)energy value of the molecular frontier molecular orbitals are analyzed,and the energy difference is compared and analyzed.The Marekken layout number,molecular polarizability and thermodynamic parameters of the three molecules are analyzed and compared.The calculation results show that the more the number of successive Ag atoms,the more significant the surface-enhanced Raman spectral intensity increases,and the lower the energy difference of HOMO and LUMO change.Surface-enhanced Raman spectroscopy provides theoretical guidance for the detection of pesticide residues in pesticides.It provides theoretical support forpesticide supervision and testing departments and import and export agricultural product residue testing departments,and provides a method for rapid,safe and simple testing of pesticide residues.
Keywords/Search Tags:Surface-enhanced Raman Spectroscopy(SERS), Density Functional Theory(DFT), pesticide residues
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