The Study On Established Of Immunesensor For Ochratoxin A In Food

Ochratoxin A(OTA),weidly distributed in crops, which has caused a great harm to public health for its extremely toxic.OTA is not easy degradated in the metabolism of human body, and can accumlate in the body. Give the huge harm of the OTA, most countries generally strengthen the regulation of it. At present,there is a diversity of analysis methods, including enzyme-linked immunosorbent assay(ELISA) and high-performance liquid chromatography(HPLC), but these methods have certain insufficiency. For example low sensitivity, test cost is higher, time consuming,determination result reliability is much worse.This research through the Hummer method preparation GO, r GO/Au decorated GCE fabricated by one-step eletrodeposition Au NPs/r GO co-decorated glassy carbon electrode. Gold nanoparticles insert in lamellar structure of graphene, effectively increase the complex surface area.1 Based on the research of OTA McAb-immune sensor1.1 Using the Hummer method preparation GO, its thickness is about 1 nm, by one-step eletrodeposition Au NPs/r GO co-decorated glassy carbon electrode.Optimization of experiment conditions, the concentration of GO and chloroauric acid respectively are 0.5 mg/m L and 1.0 m M, modified laps are five laps.1.2 Through a facile one-step deposition process by cyclic voltammetry from-1.6V to 0.6V. The immunosensor was constructed by covalently immobilizing anti-OTA Mc Ab, detection of linear equation is y=224x+546.5, the determination liner range of0.5-20 ng/m L, the limit of detection is the 0.35 ng/m L, OTA spiked real corn samples were analyzed and the average recoveries are in the range of 75%-101%.2 Based on the research of OTA Nb-immune sensor2.1The immunosensor was constructed by covalently immobilizing anti-OTA Nb via EDC/NHS activation of the carboxyl groups on the r GO/Au NPs film, through the optimization experiment, the concentration ratio of EDC/NHS is 8:1, its reaction time is 50 min. The immunesensor detected OTA for 60 min.2.2 The Nb-immunesensor,which detection of linear equation is y=224x+546.5,the determination liner range of 0.01-1 ng/m L, the limit of detection is the 0.005ng/m L, OTA spiked real corn samples were analyzed and the average recoveries are in the range of 92%-99%. While ZEN ? DON ? AFB1 and FB1 has less than 5% cross-reactivity with the immunosensor. Including the expermental results, the immunsensor has a higher sensitivity which is immobilized by nanobody.2.3 The developed method was applied to the determination of OTA in beer samples,and the results well agreed with those obtained by enzyme-linked immunosorbent assays method.It is prepared for the promotion of rapid detection technology in the future.