| During the growth of crops,pesticides are often used to prevent and control pests and weeds.The use of pesticides increases the yield of crops greatly,but excessive or other inappropriate use of pesticides resulted in the residual pesticides flowed into the water,the soil,and volatile into the atmosphere,then tract into the human body through the respiratory eventually,which will affect human and other biologies,health seriously.Most of the detection technology is dependent on large-scale equipment at present,which are expensive and need the complex pretreatment to the sample,meanwhile,the analysis often need long time and must be operated by the professional.Therefore,the development of rapid analytical technology to detect pesticides which didn,t dependent on large instruments is of great significance.In this paper,the new methods of rapid detection of the pesticide residues were established by colorimetric method and immunoassay method.The new methods have been applied to the determination of real samples with satisfactory results.The specific research contents are as follows:1.A new colorimetric assay to detect cartap in water was developed in which the para-aminobenzoic acid decorated gold nanoparticles worked as a nanoprobe.Owing to the hydrogen-bond interaction between cartap and the carboxyl group of para-aminobenzoic acid,it was found that modified AuNPs can easily aggregate in the presence of cartap,resulting in the color change from wine red to blue with a blue-shift in ultraviolet-visible absorption spectrum,which can be monitored by an ultraviolet-visible spectrophotometer or the naked eyes.The limit of detection is 0.15mg/L by the naked eyes and 0.02 mg/L by UV-Vis spectroscopy with the linear range from 0.08 to 0.7 mg/L.The proposed method was applied to the detection of cartap in environment water samples with spiked recoveries of 101%~107% and relative standard deviation(RSD)of 2.1%~4.7 %,respectively.2.Functional gold nanoparticles which was modified by the p-aminobenzamide(AMIDE)was used to detect amitrole.It was found that the amino group of p-aminobenzamide modified on the surface of gold nanoparticles could form hydrogen bonds with the amitrole,then we can observed the spectral changes and accompanied the solution changed from wine red to blue due to the aggregation ofgold nanoparticles.The visualization method to detect amitrole was established.The aggregation degree of gold nanoparticles changed by the increase of the concentration of amitrole.The detection limit of this method to amitrole was 0.023 mg/L,and the detection limit was 0.10 mg/L by naked eye.There was a good linear relationship in the range of 0.10 to 0.95mg/L.3.Friedel-Crafts reaction was used to reform the structure of forchlorfenuron(CPPU)to synthesize a novel and effective artificial antigen of forchlorfenuron.The hapten was coupling with bovine serum albumin(BSA)and ovalbumin(OVA)respectively by carbon diimine(EDC)method,to obtain forchlorfenuron immunogen and coating antigen.The molecular structural formula of forchlorfenuron hapten was identified by elemental analysis,mass spectrometer(MS)and nuclear magnetic resonance spectroscopy(1H-NMR);The artificial antigen were identified by UV spectroscopy and high performance matrix assisted laser desorption ionization time of flight mass spectroscopy(MALDI-TOF MS).The results showed the artificial antigen of forchlorfenuron had been synthesised successfully and the immune antigen was used to immunize the white rabbits of New Zealand.The results showed that the immune antigen could stimulate the white rabbits to produce specific anti-forchlorfenuron polyclonal antibody,then the indirect competitive ELISA method was established based on the polyclonal antibody to detect the forchlorfenuron of orange.The IC50 was 48 ng/mL,the detection range was between 1and 5000ng/mL,the lowest detection limit was 1 ng/mL. |
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