Nanoplatinum-enclosed gold nanocores as catalytically promoted nanolabels for sensitive electrochemical immunoassay

详细信息    查看全文

• 作者：Jun Zhou ; Dianping Tang ; Li Hou ; Yuling Cui ; Huafeng Chen ; Guonan Chen
• 关键词：Electrochemical immunosensor ; Nanoplatinum-enclosed gold nanocores ; Nanolabels ; Carcinoembryonic antigen ; Carbon nanospheres-graphene hybrid nanostructures
• 刊名：Analytica Chimica Acta
• 出版年：2012
• 出版时间：2 November, 2012
• 年：2012
• 卷：751
• 期：Complete
• 页码：52-58
• 全文大小：1035 K

文摘

Here we designed a new electrochemical immunoassay protocol for determination of carcinoembryonic antigen (CEA) using nanoplatinum-enclosed gold nanocores (Pt@Au) as catalytically promoted nanolabels on the carbon nanospheres and graphene-modified immunosensor. The Pt@Au nanolabels were synthesized and functionalized with monoclonal anti-CEA antibodies and glucose oxidase (GOx). Using the functional Pt@Au nanolabels as molecular tags, the assay was implemented relative to glucose-hydroquinone system with a sandwich-type immunoassay. Initially, the added glucose was oxidized to gluconolactone and H₂O₂ by the labeled GOx, and then the generated H₂O₂ was reduced with the help of platinum nanoparticles, leading to the production of oxygen. The self-produced oxygen could promote the re-oxidation of the glucose, thus resulting in the dual amplification of the electrochemical signal. Several nanolabels, such as multiarmed star-like platinum nanowires, hollow platinum nanospheres and Pt@Au nanostructures, were investigated for CEA detection and improved analytical features were obtained with the Pt@Au nanostructures. Under optimal conditions, the Pt@Au-based immunoassay displayed a wide working range from 0.001 to 120 ng mL^?1 with a low detection limit of 0.5 pg mL^?1 CEA at 3s_B. Intra- and inter-assay coefficients of variation were <10.9 % . The system was evaluated with 10 clinical serum samples, receiving good accordance with results from enzyme-linked immunosorbent assay method.