An ultrasensitive quenched electrochemiluminescent immunoassay based on the peroxidase-like activity of ZnFe₂O₄@Au nanoparticles

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• 作者：Lei Shen^aAuthor Vitae ; Chengchao Chu^aAuthor Vitae ; Chao Ma^aAuthor Vitae ; Hongmei Yang^aAuthor Vitae ; Shenguang Ge^bAuthor Vitae ; Jinghua Yu^aAuthor Vitae ; Mei Yan^a ; ^{chm_yanm@126.com" class="auth_mail}Author Vitae ; Xianrang Song^cAuthor Vitae
• 关键词：Electrochemiluminescence ; Peroxidase-like activity ; Zinc ferrite ; Immunosensor
• 刊名：Sensors and Actuators B: Chemical
• 出版年：1 October 2014
• 年：2014
• 卷：201
• 期：Complete
• 页码：196-203
• 全文大小：1904 K

文摘

We reported here the synthesis of zinc ferrite (ZnFe₂O₄), which was further fabricated into gold nanoparticles (AuNPs) functionalized ZnFe₂O₄ (ZnFe₂O₄@Au) through a layer-by-layer (LBL) self-assembly method. The prepared ZnFe₂O₄@Au showed excellent catalytic performance to the reduction reaction procedure of hydrogen peroxide (H₂O₂), and the coated AuNPs provided the nanoparticles with good biocompatibility. In addition, the CdTe quantum dots dotted graphene (G–CdTe) was prepared and was found with good electrochemiluminescence (ECL) property. The prepared ZnFe₂O₄@Au and G–CdTe were applied in a simple sandwich-type ECL immunosensor for carcinoembryonic antigen (CEA). In the immunosensor, G–CdTe acted as the solid support for CEA primary antibody and ZnFe₂O₄@Au was employed as the supporter of CEA secondary antibody. The ZnFe₂O₄@Au could quench the ECL signal of the G–CdTe and the quenching ECL intensity could be obtained. The proposed immunosensor enabled CEA concentrations to be determined in the 0.01–50 ng mL⁻¹ concentration range, with a detection limit of 4 pg mL⁻¹.