Enrichment,Purification And Detection Of AFB₁ Using The Photonic Crystal Microsphere

Aflatoxin is a highly toxic and carcinogenic metabolite, is produced predominantly in cereal products. This paper proposes an enrichment, purification and detection of AFB1 with inverse-opaline photonic crystal microsphere and magnetic opal photonic crystal microsphere.First, inverse-opaline photonic crystal microsphere and magnetic opal photonic crystal microsphere were prepared by Stober method. The microspheres show a regular structure and reflection peak. Then the surface of the microspheres was modified with aldehyde,carboxyl and epoxy groups.The several conditions for immunoaffinity-HPLC to enrich and purify AFB1 were optimized with inverse-opaline photonic crystal microsphere and magnetic opal photonic crystal microspheres. The aldehyde group was chosed as the optimal antibody group. The optimal eluent methanol concentration and volume was 100% methanol and 800μL,respectively. 30 μL microspheres immobilized with AFB1 antibody could enrich 50ng AFB1. The elution efficiency of inverse-opaline photonic crystal microsphere was reached to 90%,the recovery rate of AFB1 in rich,wheat,corn were 70.00±7.07～85.15±7.58%,75.00±6.59～88.21±2.31%,88.21±3.07～109.4±5.73%. Yet the relution efficiency of magnetic opal photonic crystal microsphere was reached 80 to 85%, the recovery rate of AFBi in rich,wheat,corn were 65.84±3.50～71.15±7.74%,58.66±1.06～81.66±0.70%,72.95±5.13～87.28±10.13%. Inverse-opaline photonic crystal microsphere as the carrier could achieve optimal effect by analysising the recover rate.The several conditions for the aptamer sensor to detect AFB1 were optimized with inverse-opaline photonic crystal microsphere and magnetic opal photonic crystal microspheres. The aldehyde group was chosed as the optimal group to combine aptamer.The linear range of the standard curve was in 0.01-100ng/mL based on inverse-opaline photonic crystal microsphere, the detection limit was 0.01ng/mL. The recovery rate of AFB1 in rich, wheat,corn was 94.04±10.30～112.4±9.35%,78.17±10.69～88.69±6.94%,88.71±7.23～101.38±8.67%. The linear range of the standard curve was in 0.01-10ng/mL based on magnetic opal photonic crystal microsphere, the detection limit was 0.01ng/mL.The recovery rate of AFB1 in rich, wheat,corn was 64.09±7.88～75.72±4.70%,62.62±4.79～72.50±6.51%,69.60±4.15～81.67±3.56%. The determination of the recovery rate of argricultural products was consistent with the ELISA method, which proved the feasibility of the method. As aptamer sensor, inverse-opaline photonic crystal microsphere as carrier could achieve better effect than magnetic opal photonic crystal microsphere.