The Fabrication Of Aptasosensor Based On Nano Materials Modified Electrode

This research was studied on the aptasensor based on different nano materials. Thebasic modification and the analysis method of the aptasensor through fabricating theaptasensor for dopamine detection had been mastered. The aptasensor had beensuccessfully used for the tetracycline residue detection in th milk. The researches could besummarized as follows:1. An aptasensor had been proposed for the dopamine (DA) detection by usingmulti-walled carbon nanotubes-chitosan (MWCNTs-CS) and graphene-thionine-goldnanoparticles (GR-Thi-AuNPs). I had learnt the basic principle of the aptasensor, and Imastered the modification and fixed method of the aptamer in the process of experimentthrough fabricating the aptasensor for dopamine detection. The characterization ofelectrochemical and the scanning electron microscopy indicated that the aptasensor couldbe used for the dopamine detection, demonstrating that aptasensor could be used for thepossibility of tetracycline residue detection.2. A novel and sensitive electrochemical aptasensor for detecting tetracycline (TET)with Prussian blue (PB) as the label-free signal was fabricated. Based on the research ofthe aptasensor for dopamine detection, I applied the principle of aptasensor built a sensorfor tetracycline detection, in which PB-chitosan-glutaraldehyde (PB-CS-GA) system actingas the signal indicator was developed to improve the sensitivity of the electrochemicalaptasensor. Under the best controlled environment, the proposed aptasensor indicated a lowdetection limit of3.2×10-10M in the wide range of10-9-10-2M, but the linear relationshipis not very good.3. An aptasensor was developed based on the multi-walled carbon nanotubes-chitosan(MWCNTs-CS) and chitosan-prussian blue-graphene (CS-PB-GR) nanoparticles. Faced tothe disadvantage of linear relationship is not good appeared in experiment two, the goodconductive properties of multi-walled carbon nanotubes and graphene were used toimprove the sensitivity of the aptasensor. The MWCNTs-CS combined with CS-PB-GRshowed good performance in the aspect of increasing the sensitivity and stability of theelectrode. The proposed aptasensor showed detection range from1×10-10M to1×10-3Mand LOD1.43×10-11M, by comparison with the results showed that had achieved the goal of the experimental optimization. Further, the contructed aptasensor was able to detect TETin milk and recoveries were satisfactory, which indicated that it could be used as apre-scanning method in TET determination for the analysis of livestock products.