Ultrasensitive electrochemical immunosensor based on Au nanoparticles dotted carbon nanotube-graphene composite and functionalized mesoporous materials

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• 作者：Juanjuan Lu^a ; Shiquan Liu^b ; Shenguang Ge^a ; Mei Yan^a ; Jinghua Yu^a ; ^{ujn.yujh@gmail.com} ; Xiutao Hu^a
• 关键词：Carbon nanotubes ; Mesoporous silica nanoparticles ; Grapheme ; Electrochemical immunosensor ; Human chorionic gonadotrophin
• 刊名：Biosensors and Bioelectronics
• 出版年：2012
• 期刊代码：12_09565663
• 类别：ch
• 出版时间：15 March, 2012
• 卷：33
• 期：1
• 页码：29-35
• 文件大小：1332 K

摘要

A facile and sensitive electrochemical immunosensor for detection of human chorionic gonadotrophin (hCG) was designed by using functionalized mesoporous nanoparticles as bionanolabels. To construct high-performance electrochemical immunosensor, Au nanoparticles (AuNPs) dotted carbon nanotubes (MWCNTs)-graphene composite was immobilized on the working electrode, which can increase the surface area to capture a large amount of primary antibodies (Ab₁) as well as improve the electronic transmission rate. The as-prepared bionanolabels. composed of mesoporous silica nanoparticles (MCM-41) coated with AuNPs through thionine linking, showed good adsorption of horseradish peroxidase-labeled secondary anti-hCG antibody. Interlayer thionine was not only a bridging agent between MCM-41 and AuNPs but also an excellent electron mediator. The approach provided a good linear response range from 0.005 to 500 mIU mL^鈭? with a low detection limit of 0.0026 mIU mL^鈭?. The immunosensor showed good precision, acceptable stability and reproducibility. Satisfactory results were obtained for determination of hCG in human serum samples. The proposed method provides a new promising platform of clinical immunoassay for other biomolecules.