Study On Simultaneous Detection Of Three Mycotoxins In Grains And Chinese Medicinal Based On Spherical And Flower-Shaped Gold Nano-Immunochromatographic Test Strips

Mycotoxins are secondary metabolites produced by some filamentous fungi.Among them,zearalenone(ZEN),deoxynivalenol(DON)and ochratoxin A(OTA)are widely present in grains,oils and feeds.It has a relatively large toxic effect on both humans and animals,and poses a major threat to food security.This paper has developed two colloidal gold immunochromatographic test strips that can simultaneously detect ZEN,DON and OTA in cereals and Chinese medicinal materials.The specific research contents and results are as follows:(1)Use the Frens method to prepare Au NSs,control the addition of the reducing agent trisodium citrate to investigate the size and morphology of the nano-gold,and select the particle size to be 26 nm(the addition of trisodium citrate is 1.4 m L)is the best immunolabeling material.By optimizing the process parameters of the test strip,The GICA based on Au NSs that can detect ZEN,DON and OTA at the same time has been developed.The sensitivity of the test strip for detecting ZEN is 6 ng/m L,the sensitivity for detecting DON is 20 ng/m L,and the sensitivity for detecting OTA is 1ng/m L.(2)The Au NFs was prepared by the gold seed-mediated growth method,and the amount of chloroauric acid,gold seeds and hydroquinone were controlled toinvestigate the particle size and morphology of the Au NFs.Finally,gold nanoparticles with many branches and long spikes on the surface were selected(0.35 m Lchloroauric acid solution,0.35 m L gold seed solution,0.1 m L sodium citrate solution and 0.5 m L hydroquinone solution)are the best immunolabeling materials,and the process parameters of the test strips are optimized.The GICA based on Au NFs that can detect ZEN,DON and OTA at the same time.The sensitivity of the test strip for detecting ZEN is 3 ng/m L,and the sensitivity for detecting DON is 10 ng/m L.thesensitivity for detecting OTA is 0.5 ng/m L,the detection sensitivity has been doubled.(3)The GICA based on Au NSs and Au NFs developed in this article have undergone an experimental evaluation of specificity and stability(environmental acceleration test).The results show that the test strip has good stability and does not cross-react with the other three common mycotoxins(AFB₁?FB₁?T2).(4)The GICA based on Au NSs and Au NFs are applied to the detection of ZEN,DON and OTA in grains and Chinese medicinal materials.Procured 35 grain samples(25 wheat,10 corn)and 25 traditional Chinese medicine samples(11 barley,14scutellaria)from local markets and e-commerce platforms,After the sample is processed,it is applied to the test strip test,and the test is verified by HPLC.Experiments show that the detection results of the two are in good agreement,so the GICA based on Au NSs and Au NFs developed in this article can be applied to thepreliminary screening of large-scale samples on site.