Double signal amplification sandwich-structured immunosensor based on TiO_2 nanoparticles enhanced CdSe@ZnS QDs electrochemiluminescence and the dramatic quenching effect of Au@polydopamine nanoparticles  

作　　者：Qi-Le Li Shou-Nian Ding 

机构地区：[1]School of Chemistry and Chemical Engineering, Southeast University

出　　处：《Science Bulletin》2016年第12期931-938,共8页科学通报（英文版）

基　　金：supported by the National Natural Science Foundation of China (21575022, 21535003);the National High Technology Research and Development Program of China (2015AA020502);the Open Research Fund of Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University;the Fundamental Research Funds for the Central Universities (KYLX15-0127)

摘　　要：In this work, a double signal amplified immunosen- sor based on the enhanced CdSe@ZnS quantum dots （QDs） electrochemiluminescence （ECL） via TiO2 nanoparticles （TiO2 NPs） and the outstanding quencher of polydopamine （PDA） decorated Au nanoparticles （Au@PDA NPs） for ultrasensitive detection of carcinoembryonic antigen （CEA） has been successfully achieved. The ECL of CdSe@ZnS QDs with different sizes has been investigated carefully, especially cooperation with TiO2 NPs. Au@PDA NPs have been synthesized and characterized by transmission electron microscopy （TEM） and UV-Vis spectrum, which acted as ECL quenchers to label the secondary antibody （Ab2） of CEA to form Ab2/Au@PDA NPs conjugates. The sandwich-structured immunosensor was formed between capture antibody （Abl） on CdSe@ZnS QDs/TiO2 NPs/glassy carbon electrode, CEA and Ab2/Au@PDA NPs conjugates, resulting in a proportional ECL quenching signal relevant to the CEA concentration. Thus, CEA as a model biomarker has been detected in the linear range from 0.001 to 100 ng mL^-1 with a limit of detection of 0.35 pg mL^-1 （S/N = 3）.In this work, a double signal amplified immunosensor based on the enhanced CdSe@ZnS quantum dots(QDs)electrochemiluminescence(ECL) via TiO_2 nanoparticles(TiO_2 NPs) and the outstanding quencher of polydopamine(PDA) decorated Au nanoparticles(Au@PDA NPs) for ultrasensitive detection of carcinoembryonic antigen(CEA)has been successfully achieved. The ECL of CdSe@ZnS QDs with different sizes has been investigated carefully, especially cooperation with TiO_2 NPs. Au@PDA NPs have been synthesized and characterized by transmission electron microscopy(TEM) and UV–Vis spectrum, which acted as ECL quenchers to label the secondary antibody(Ab_2) of CEA to form Ab_2/Au@PDA NPs conjugates. The sandwich-structured immunosensor was formed between capture antibody(Ab_1) on CdSe@ZnS QDs/TiO_2 NPs/glassy carbon electrode,CEA and Ab_2/Au@PDA NPs conjugates, resulting in a proportional ECL quenching signal relevant to the CEA concentration. Thus, CEA as a model biomarker has been detected in the linear range from 0.001 to 100 ng mL^(-1) with a limit of detection of 0.35 pg m L^(-1) (S/N = 3).

关 键 词：ELECTROCHEMILUMINESCENCE CdSe@ZnSQDs TiO2 NPs Au@PDA nanoparticles IMMUNOSENSOR 

分 类 号：TB383.1[一般工业技术—材料科学与工程] TP212[自动化与计算机技术—检测技术与自动化装置]