Study On Immunochromatogriphic Assay For Simultaneous Detection Fumonisin B₁ And DON In Grains And Chinese Medicine

Mycotoxin is a type of toxic secondary metabolite.Fumonisin B₁?FB₁?and deoxynivalenol?DON?are two water-soluble toxins in several common mycotoxins.At present,they mainly contaminate cereals and feed stuffs,which can cause irreversible damage to human and animals.In recent years,the contamination of Chinese medicinal by FB₁ and DON has been attracted widespread attention.In this paper,two methods of immunochromatographic assay?ICA?,which were spherical gold nanoparticles?AuNSs?and flower-like gold nanoparticles?AuNFs?,were used to qualitatively detect the levels of FB₁ and DON in grains and Chinese medicine whether exceeded the limit of 1 mg/kg.Firstly,the AuNSs prepared by trisodium citrate reduction method were used as immune-markers to develop an immunochromatographic strip for simultaneous detection of FB₁ and DON.To investigate the effects of trisodium citrate addition on the particle size and strip sensitivity of the AuNSs:The amount of trisodium citrate was inversely proportional to the particle size of the AuNSs.And the size change of AuNSs had no significant effect on the sensitivity of the strip,when the particle size of the AuNSs ranged from 20 to 30 nm.After optimizing the experimental conditions,the optimal AuNSs prepared by adding 1.4 mL of trisodium citrate was used to develop an immunochromatographic strip?ICS?for simultaneous detection of FB₁and DON.The sensitivity of ICS based on AuNSs for FB₁ and DON was 20 ng/mL.Secondly,AuNFs prepared by gold seed-mediated growth method were used as immune-markers to develop ICS for simultaneous detection of FB₁ and DON.To investigate the effects of the amount addition of chloroauric acid,gold seed solution and hydroquinone on the particle size and strip sensitivity of the AuNFs:The addition of chloroauric acid and seed solution were inversely proportional to the particle size of the AuNFs and the addition of hydroquinone was directly proportional to the particle size of the AuNFs.The larger specific surface area of AuNFs is more conducive to improve the sensitivity of ICS,when the branch in the surface of AuNFs is obvious.After optimizing the experimental conditions,the optimal AuNFs prepared by adding 0.25 mL chloroauric acid,300 mL seed solution and 0.5 mL hydroquinone was used to develop ICS for simultaneous detection of FB₁and DON.The sensitivity of ICS based on AuNFs for FB₁ and DON was 5.0 ng/mL,which indicated that the sensitivity of ICS based on AuNFs compared with ICS based on AuNSs increased four times.Finally,the ICS based on AuNSs and AuNFs for simultaneous detection of FB₁and DON were applied to the detection of FB₁ and DON in grains and Chinese medicine.A total of 116 samples?51 wheat samples,18 maize samples and 47Chinese medicine samples?were purchased in local markets,online sales and other places.Compared with HPLC and ELISA,the result of strips had good consistency.Therefore,the two kinds of ICS developed in this paper are suitable for screening large quantities of samples in the field.