Double signal amplification sandwich-structured immunosensor based on TiO2 nanoparticles enhanced CdSe@ZnS QDs electrochemiluminescence and the dramatic quenching effect of Au@polydopamine nanoparticles

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• 作者：Qi-Le Li ; Shou-Nian Ding
• 刊名：Chinese Science Bulletin
• 出版年：2016
• 出版时间：June 2016
• 年：2016
• 卷：61
• 期：12
• 页码：931-938
• 全文大小：1,481 KB
• 刊物主题：Science, general; Life Sciences, general; Physics, general; Chemistry/Food Science, general; Earth Sciences, general; Engineering, general;
• 出版者：Springer Berlin Heidelberg
• ISSN：1861-9541
• 卷排序：61

文摘

In this work, a double signal amplified immunosensor 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 (Ab₁) 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).KeywordsElectrochemiluminescenceCdSe@ZnS QDsTiO₂ NPsAu@PDA nanoparticlesImmunosensor