论文部分内容阅读
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).
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) The ECL of CdSe @ ZnS QDs with different sizes has been investigated carefully, especially 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 linea r range from 0.001 to 100 ng mL -1 with a limit of detection of 0.35 pg m L -1 (S / N = 3).