Triple signal amplification using gold nanoparticles, bienzyme and platinum nanoparticles functionalized graphene as enhancers for simultaneous multiple electrochemical immunoassay

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• 作者：Xinle Jia ; Xia Chen ; Jingman Han ; Jie Ma ; Zhanfang Ma
• 关键词：Graphene ; Signal amplification ; Simultaneous multianalyte detection ; Electrochemical immunoassay ; Tumor markers
• 刊名：Biosensors and Bioelectronics
• 出版年：15 March, 2014
• 年：2014
• 卷：53
• 期：Complete
• 页码：65-70
• 全文大小：2114 K

文摘

Here we demonstrated an ultrasensitive electrochemical immunoassay employing graphene, platinum nanoparticles (PtNPs), glucose oxidase (GOD) and horseradish peroxidase (HRP) as enhancers to simultaneously detect carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP). This immunosensor is based on the observation that multiple-labeled antibodies (thionine-labeled anti-CEA and ferrocene-labeled anti-AFP) recognition event yielded a distinct voltammetric peak through 鈥渟andwich鈥?immunoreaction, whose position and size reflected the identity and level of the corresponding antigen. Greatly enhanced sensitivity for cancer markers is based on a triple signal amplification strategy. Experimental results revealed that the immunoassay enabled simultaneous determination of CEA and AFP in a single run with wide working ranges of 0.01-100 ng mL^鈭?. The detection limits reached 1.64 pg mL^鈭? for CEA and 1.33 pg mL^鈭? for AFP. No obvious cross-talk was observed during the experiment. In addition, through the analysis of clinical serum samples, the proposed method received a good correlation with ELISA as a reference. The signal amplification strategy could be easily modified and extended to detect other multiple targets.