Research Of Application In Chemiluminescent Aptasensors In Food Contamination Detection

The food contaminants have serious threaten to human health,at the same time,food safety issues have got more and more attention.It is necessary to detect the food contaminants.Finding more sensitive,faster,and more convenient detection methods of food contaminants is an imminent task.We designed the aptasensors for detection of food contaminants by chemiluminescence?CL?.The main detected substance is Ochratoxin A?OTA?which is a mycotoxin in food,Chloramphenicol?CAP?,which is a residual antibiotic in food,and Adenosine triphosphate?ATP?which is in the vivo of contaminated bacteria in food.?1?High Performance Liquid Chromatography with Fluorescence Detector for detecting OTAIn this part,we detected OTA by High Performance Liquid Chromatography with Fluorescence Detector?HPLC-FLD?.First,the standard curve of peak area??V?and OTA concentration was established for OTA standards using HPLC area normalization method.The OTA spiked in pre-treated beer samples has been extracted and purified by C18 solid phase extraction cartridge,and then done recovery experiment.The results showed that peak area and OTA concentration existed a good linear relationship,the limite of detection?LOD?was 0.1 ng/m L,the average recovery rate was 98.3%¹02.1%,the method with good precision and sensitivity.?2?Detection of Ochratoxin A by Hydroxylamine-amplified Gold Nanoparticles ChemiluminescenceWe used gold nanoparticles?AuNPs?to catalyze Luminol chemiluminescence system to enhance the chemiluminescent signal,established a Au NPs-aptamer biosensor,amplifyed effect on biosensor by NH₂OH/HAuCl₄,for indirect quantitative detection of OTA.Under optimized conditions,we established the standard curve of chemiluminescence??CL?and OTA concentrations,examined the specificity of biosensor.Biosensor has been used to detect OTA in spiked beer and corn at last.The results showed that?CL and OTA concentrations existed a good linear relationship,the LOD was 1.58×10^-3 ng/m L,the average recovery rate was 95.9%¹07.7%,the biosensor has strong specificity.Compared to the second chapter of the HPLC detection OTA,this method had better linear range and LOD.At the same time,this method has simple pre-processing steps to save a lot of time and costs.?3?Simultaneous detection of ATP and CAP based on label-free aptasensor by ChemiluminescenceIn this part,we established a ATP/CAP aptasensor by Carboxy magnetic microspheres and carboxyl polystyrene microspheres to detect ATP/CAP mixture.We examined the specificity of ATP/CAP aptasensor.And the ATP/CAP aptasensor has been used to detect ATP and CAP in spiked beer and milk.The results showed that?CL and ATP/CAP concentrations existed a good linear relationship,the LOD of ATP and CAP were 3.76×10^-8 mol/L and 2.48×10^-8 mol/L ng/mL,the average recovery rate was 95.1%¹06.3%,and the method has strong specificity.