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).
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)
