Homemade Nanoparticles Carrier Combining With Label-free Aptamer Sensor Chemiluminescence Detection Application

The content of contaminants in food affects human health and life safety.It is necessary to monitor it directly or indirectly.In order to study a convenience,sensitive,high-speed detection technology,two kinds of nanoparticles are prepared.Then,label-free aptamer sensors based on homemade nanoparticles are designed and detection conditions are optimized.ATP?Adenosine triphosphate?,chloramphenicol and Ochratoxin A?OTA?are detected by chemiluminescence,which are closely related to food safety.The main contents are as follows:?1?Aptamer based on homemade Fe₃O₄ nanoparticles is used to detect ATP.Fe₃O₄ nanoparticles are prepared by coprecipitation method.The composition and particle size of Fe₃O₄ nanoparticles are characterized by X-ray diffraction,Fourier transform infrared spectroscopy,magnetic absorption,UV-Vis absorption spectroscopy and transmission electron microscopy.Finally,The results show that the homemade Fe₃O₄ particles have uniform particle size,good magnetic properties,good stability,good amino modification.The detection limit of ATP is 6.80 × 10-7 mol/L,and 3.98×10-8 moL ATP is detected out in 1mL yogurt.?2?Aptamer based on homemade SiO₂ nanoparticles is used to detect chloramphenicol.Firstly,SiO₂ nanoparticles are prepared by sol-gel method.Then,the aptamer sensor for chloramphenicol is prepared using the homemade SiO₂ nanoparticles.The results show that the detection limit of chloramphenicol is 3.26×10-9 mol/L,while the one based on commercialized magnetic microspheres is 3.57×10-9 mol/L,and applying to the detect chloramphenicol in spiked milk samples,the detection rate are between 94.1% 103.0%.?3?Separated by magnetic effect,ATP is detected by the aptamer based on homemade SiO₂ nanoparticles,OTA is detected by the aptamer based on homemade Fe₃O₄ nanoparticles.The results show that the detection limits of ATP and OTA are 1.43×10-7 mol/L and 8.32×10-8 mol/L,and applying to the detect ATP and OTA in spiked beer samples,the detection rate are between 94.2 %¹01.0 %.