| Mycotoxins are known as the toxic fungal secondary metabolites produced either in the field or during transportation, processing, or storage of cereals. Humans or animals exposure happen by ingestion of the mycotoxin-contaminated foods or feeds which can cause a series of serious health problems, such as immunosuppression and carcinogenesis and so on. A lot of food crops in the world are contaminated by mycotoxins each year, which leads to both considerable financial damage and safety risks. In modern agricultural production, pesticides as chemicals, play an important role to kill or inhibit injurious insects, weeds, fungi, bacteria, or other organisms. Up to date, pesticides are produced about 2 million tons of pesticides every year and widely used in farmlands, orchards, and greenhouses. 1000 kinds of synthetic compounds are the relation with manufacturing pesticide, fungicide, algaecide and deciduous agent. For the most pesticides, intake, inhalation, or exposure to them would be noxious even to man.In recent years, mycotoxins and pesticide residues widely exist in foods and feeds, which is a serious danger to people health and food safety. The risk of mycotoxins and pesticide residues in agricultural products has caused the critical concern to today society. Therefore, with the development of society and science, high-efficiency detection for mycotoxins and pesticide residues has turned to be a inevitable demand in our life. For this purpose, the works in my master career were designed and carried out.The methods to detect the presence of mycotoxins and pesticide residues have been diversified. However, all these methods have both advantages and disadvantages under the current situation, as a result, how to detect mycotoxins fastly, sensitively, accurately and conveniently turns out to be highly desirable. In my paper, there were three works based on Surface Enhanced Raman scattering(SERS), including the spectra analysis and real samples detection of deoxynivalenol(DON), patulin(PAT) and thiophanate-methyl(TM). Gold or silver nanoparticles were synthesized firstly and applicated in spectra analysis and samples detection. In order to further understanding of these acquired spectra, density functional theory(DFT) analysis atthe level of B3LYP/ 6-311 ++ G(d, p) or 6-31 + G(d, p) was also performed for vibrational assignment.In the first work for DON, the SERS spectra of DON solutions in different concentrations were acquired, and the limit of detection was down to 10-7 M. For real samples, the LODs of 10-6 M in corns and kidney beens were both down to Chinese standard limits. In the second work for PAT, the Raman and SERS spectra tests were both performed. And then, DFT calculations with two kinds of modes were used for the attributions. In the third work for TM, not only the Raman and SERS spectra were detected and attributed, but TM in apples and pears were also detected with the LODs of 10-6 M which were under Chinese standard limits.In my works during master career, comparing with previous reports, it was the first time to test and attribute SERS spectra of DON and PAT. The spectra analysis and attribution datas of TM were more detailed than before. Besides the DFT calculations for two kinds of modes of metal nanoparticles improved the value of this experiment.As a perspective, the SERS technology could be developed into an alternatively promising assay for identification, analysis and detection of mycotoxin and pesticide molecules in food.
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