Study On New Techniques For Determination Of Zearalenone Contamination In Grain Or Feed

Zearalenone?ZEN?is a mycotoxin produced by several species such as Fusarium graminearum and Fusarium culmorum.ZEN is one of the most widely contaminated mycotoxins,which can contaminate water sources and food crops in various ways.Because of its estrogen-like activity and genetic toxicity,ZEN can cause serious functional damage to human reproductive system,central nervous system and other systems,inducing a serious of health effects on humans.ZEN has aroused people's attention and appropriate methods are needed to sensitively detect this contaminant in food.In recent years,with the rapid development of nanotechnology,electrochemical sensors show the advantages of high sensitivity,good specificity and simple operation,which have potential in the fields of medical,environmental and food safety monitoring,and also provide a new idea for the sensitive detection of Zen.Aptamers are oligonucleotides with high specificity and target-binding affinity,which are especially suitable for the recognition and detection of low molecular weight substances.Therefore,aptamers are widely used in the field of electrochemical biosensors.Based on these,this study intends to use new nano materials,nano sensing technology and aptamers to constructe a novel electrochemical aptasensor to achieve sensitive detection of ZEN.Firstly,we herein demonstrate a facile chelated method that allows the combination of copper?II?ions and L-glutamic acid?L-Glu?to synthesize a brand-new type of nanocarriers-3D sakura-shaped Cu@L-Glu metal–organic coordination polymers?MOCPs?.The Cu@L-Glu MOCPs synthesized in this experiment not only have large specific surface area,good biocompatibility synthesized in this experiment and it surface contains rich amino groups that can be used for further modification.Palladium-platinum nanoparticles?Pd-PtNPs?can synergistically catalyze the hydrogenperoxide?H₂O₂?,promote electron transfer and further improve biocompatibility.In view of the advantages of Cu@L-Glu MOCPs and Pd-PtNPs,we modified the surface of Cu@L-Glu MOCPs with Pd-PtNPs to prepare a new type of signal label Cu@L-Glu/Pd-PtNPs.Using its excellent electrocatalytic activity,the signal was amplified and the sensitivity of the sensor was improved.Then,spherical Au-PANI-Au nanocomposites were prepared by one-step method for the first time,which not only have large specific surface area and good electron transfer ability,but also can use the strong interaction between gold nanoparticles?AuNPs?and amino groups to immobilize a large number of aptamers labeled by amino groups,thus further improving the sensitivity of the sensor.Finally,a novel electrochemical aptasensor for ultrasensitive detection of ZEN was constructed based on ZEN aptamer,new signal label Cu@L-Glu/Pd-PtNPs and the electrode modification material spherical Au-PANI-Au nanocomposite.Under the optimal conditions,the electrochemical aptasensor exhibited desirable sensitive detection of ZEN with a wide linearity ranging from 1 fg/mL to 100 ng/mL and a relatively low detection limit of 0.45 fg/mL?S/N=3?,indicating the proposed electrochemical aptasensor has potential application for ZEN detection in food samples.