P1DH.1 - A Sensitive Amperometric Immunosensor Based on AuNPs-TiO2-graphene Nanocomposites for the Detection of Carcinoembryonic Antigen

17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
Vienna, Austria
P-1 - Sensors for Diagnostics and Healthcare
L. Luo, L. Zhang, Y. Chen, D. Deng, X. Yan - College of Sciences, Shanghai University, Shanghai (China)
657 - 658


A novel and sensitive sandwiched amperometric immunosensor was fabricated which mainly took advantage of AuNPs-TiO2-graphene nanocomposites as immobilizing enzyme-labeled antibody for the detection of carcino-embryonic antigen (CEA). By strong affinity effect between TiO2 and enediol bond of hematoxylin, nano-sized graphene oxide (GO) sheets which functionally modified by hematoxylin could effectively coat almost totally on the surface of TiO2 spheres. Besides, TiO2 could reduce HAuCl4 solution to produce gold nanoparticles under ultraviolet light irradiation condition. Depending on their synergistic effect, a large number of secondary antibody (Ab2) labeled Horseradish peroxidase was immobilized on the AuNPs-TiO2-graphene nanocomposites. Primary antibody (Ab1) was immobilized on the electrode by the means of the gold nanoparticles which was through electrochemical reduction of HAuCl4 solution on the surface of bare glassy carbon electrode. Under the effect of the specific immunoreaction, on the one hand CEA was connected to Ab1 and on the other hand it was further combined with as-prepared HRP-Ab2 immobilized on the nanocomposites. Under the optimization of determination conditions, a linear current response to CEA was obtained in a wide range from 1 pg/mL to 200 ng/mL (R2= 0.9927). Furthermore, the results suggest that the proposed immunosensor will be a promising alternative tool for the diagnostics application in the detection of CEA.