| This article is based on hydrogel photonic beads as the carrier and based on chemiluminescence immunoassay techniques to establish a set of multiplex detection method to detect mycotoxins in agriculture products. The main studies of this paper includes self-assembly of hydrogel photonic beads, characterization of hydrogel photonic beads, chemical modification on the surface of hydrogel photonic beads, the optimization of reaction conditions and establishment of standard curve and detecting recovery rate on single detecting FB1 in agriculture products, the optimization of reaction conditions and establishment of standard curve and detecting recovery rate on multiplex detecting FB1, AFB1 and OTA in agriculture products, using liquid chromatography-tandem mass spectrometry method to detect recovery rate of mycotoxin in agricultural products.We use hydrogel to fill in internal space of SiO2 photonic crystal to get hydrogel photonic beads. We use scanning electron microscopy and fiber optic spectroscopy to characterize hydrogel photonic beads.Then make chemical modification on the surface of hydrogel photonic beads, which can enhance the capacity of its combination with biological molecules.Hydrogel photonic bead not only has the advantages of high surface but also can avoid non-specific adsorption because of its internal solid, which make the detection background signal low, higher sensitivity and smaller signal error. The optimization of reaction conditions on single detecting FB1:coating buffer is pH= 9.6 carbonate buffer, of coating FB1-BSA antigen concentration is 1000 ng/mL, dilution of FB1 monoclonal antibody is 1:30000, dilution HRP-IgG is 1:6000. Then we use these reaction conditions to make linear regression analysis, the curve linear range is 0.0001-lng/mL, the standard curve is y=-4037.89x+927.36, R2=0.997. The specific experiment shows that there is no significant cross-reactivity with FB1 analogues. The recoveries rate from different concentrations of FB1 in agricultural products is:92.30±4.70%-107.59±8.07% in rice, 78.91±11.20%-99.70±0.42% in corn,78.60±0.71%-128.45±6.34% in wheat.During multiplex detection, the linear range is 0.001-10ng/mL for FB1,0.0001-1 ng/mL for AFB1 and OTA, standard curve is y=-2606.027x+3170.360 (R2=0.995)、 y=-2462.584x+1098.877 (R2=0.996)、y=-2839.9661x+2163.278 (R2=0.997), respectively for FB1, AFB1 and OTA. Add different concentrations of FB1, AFB1 and OTA in rice, corn and wheat, then detect the recovery rate:74.96±5.82%-87.89±8.34% for FB1,86.54± 7.42%-95.84±8.31% for AFB1,79.29±4.99%-101.03±7.26% for OTA in rice, 78.95±1.97%-101.41±9.23% for FB1,87.27±5.11%-97.07±8.60% for AFB1, 82.79±4.53%-95.92±8.83% for OTA in corn,88.56±7.64%-104.87±5.77% for FB1,86.53±5.35%-102.80±5.37%% for AFB1,84.59±6.34%-92.84±5.79% for OTA in wheat.Compared this method with liquid chromatography-tandem mass spectrometry method, we get the result that the recovery rate of these two methods almost get the same results, the correlation coefficient and correlation coefficient of the detection results of mycotoxins in 20 grain samples were respectively:FB1 y=1.105x+0.084(R2=0.945), AFB1 y=1.127x-0.037(R2=0.905), OTA y=1.074x-0.089(R2=0.968), which further verify the feasibility of detecting mycotoxins with this method in agricultural products. |
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