Corallite-like Magnetic Fe3O4@MnO2@Pt Nanocomposites as Multiple Signal Amplifiers for the Detection of Carcinoembryonic Antigen

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• 作者：Dan Wu ; Hongmin Ma ; Yong Zhang ; Hongying Jia ; Tao Yan ; Qin Wei
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：August 26, 2015
• 年：2015
• 卷：7
• 期：33
• 页码：18786-18793
• 全文大小：437K
• ISSN：1944-8252

文摘

A nonenzymatic sandwich-type electrochemical immunosensor using corallite-like magnetic Fe₃O₄@MnO₂@Pt nanocomposites was developed for the sensitive detection of carcinoembryonic antigen (CEA). First, aminated graphene (GS-NH₂) sheets were synthesized from graphite oxide using the Hummers鈥?method, which was used to immobilize the primary antibody via the active amino groups on the GS-NH₂. Second, corallite-like Fe₃O₄@MnO₂@Pt nanoparticles (NPs) were synthesized and characterized by transmission electron microscope (TEM), scanning electron microscope (SEM), and energy dispersive spectroscopy (EDS). They were used as labels to conjugate with a secondary antibody. The multiple amplification of Fe₃O₄@MnO₂@Pt NPs and the promoted electron transfer of GS-NH₂ lead to a broad linear range from 0.5 pg/mL to 20 ng/mL and a low detection limit with 0.16 pg/mL. In addition, the immunosensor performed with good selectivity and acceptable stability and reproducibility as well. The results are satisfactory when the proposed method has been applied to analyze human serum samples. Thus, there would be a promising future in the early diagnosis of cancer to detect CEA and other tumor markers.