Multivariate Detection Of Mycotoxins Based On Surface-enhanced Raman Spectroscopy Photonic Crystal Microsphere Biochip

Mycotoxins have always restricted the development of global crops and are extremely harmful to humans.It is especially important to develop a fast,sensitive,efficient and cost-effective detection method.Surface enhanced Raman spectroscopy(SERS)technology combined with photonic crystals,the SERS has the characteristics of high sensitivity,simple pretreatment and strong stability.It can be used for the detection of mycotoxins,which can achieve high sensitivity and high accuracy.In this paper,photonic crystal microspheres with uniform size and structurally stable Raman labels were prepared.The immune competition reaction was used to optimize the concentrations of AFB1-Ab and AFB1-BSA,and the detection method of AFB1 was established.The optimal concentration of AFB1-Ab was 60 ?g/mL,the concentration of AFB1-BSA was 20 ?g/mL,the linear range of AFB1 was 10-3-10 ng/mL,the linear equation was y=-7816.007461ogx+198.80679,R2=0.998,and the detection limit was 7.779 pg/mL.Specific analysis of AFB1 using AFG1 toxin showed that the method had good specificity and there was no cross-reactivity between the two.In the spiked recovery of cereal samples,the method compared with the ELISA method showed that the recovery rates of both were almost 80-120%,indicating that the method established in this paper can be used to detect mycotoxins in cereals.This method was applied to the detection of OTA and ZEN to optimize the antigen-antibody concentration of OTA and ZEN.The optimal concentrations of OTA-BSA,OTA-Ab,ZEN-BSA and ZEN-Ab were 80 ?g/mL,40 ?g/mL,40 ?g/mL?and 40 ?g/mL,respectively.The standard curves of two mycotoxins were drawn according to the optimized conditions.The detection linear range for OTA is 0.01-1 ng/mL and the linear equation is y=-10112.58051ogx+39217.39061,R2=0.998,with the detection limit at 18 pg/mL.The detection linear range for ZEN is 0.01-10 ng/mL and the linear equation is y=-10198.1161ogx+19882.29574,R2=0.999,with the detection limit at 0.503 pg/mL.Finally,a method for simultaneous detection of multiple mycotoxins was established.The results showed that the detection linear range for AFB]is between 10-3-0.1 ng/mL,and the linear equation is y=-18210.558361ogx+13100.95808,R2=0.987,and the detection limit is 34.755 pg/mL.The detection linear range for OTA is between 0.01-10 ng/mL,linear equation is y=-10455.753781ogx+23448.94951,R2=0.995,and the detection limit is 47.089 pg/mL.The detection linear range for ZEN is between 10-3-0.1 ng/mL,and the linear equation is y=-5285.633561ogx+31937.25143,R2=0.991,and the detection limit is 0.042 pg/mL.The specificity analysis of the detection system showed a good specificity for multiplex mycotoxins.The recovery rates of the three mixed toxins in the actual samples were detected with this developed method and ELISA.The results showed that the recovery rates for multiplex mycotoxins were agreement between the two methods.This indicates that the established method for detecting multiple mycotoxins is feasible.