Sirtuin 1 evaluation with a novel immunoassay approach based on TiO2-Au label and hyperbranched polymer hybrid.
Accurate and highly sensitive evaluation of the sirtuin 1 (SirT1) level is becoming increasingly important for understanding the contribution of SirT1 in metabolism pathways. Here, a novel electrochemical immunoassay of SirT1 based on crosslinked hyperbranched azo-polymer decorated with gold colloids (Au-HAP) as sensing platform and titanium dioxide (TiO2)-Au nanocomposites to immobilize secondary antibody-horseradish peroxidase (Ab2-HRP) as electrochemical labels has been designed. Greatly enhanced sensitivity was achieved by exploiting the excellent conductivity of Au nanoparticle, the amplification effect of Au-HAP and TiO2-Au, and the favorable catalytic ability of HRP. The nanocomposites of Au-HAP and TiO2-Au could attach numerous capture antibodies on the surface for significant immune recognition efficiency. Meanwhile, the TiO2-Au-labeled Ab2-HRP using an HRP-thionine-H2O2 (hydrogen peroxide) detection system could further induce signal readout. Under optimal conditions, the signal intensity was linearly related to the concentration of SirT1 in the range of 1-500 ng ml(-1), and the limit of detection was 0.28 ng ml(-1). The developed biosensor exhibits attractive performance for the analysis of SirT1, with rapid response, high sensitivity, and high accuracy, and could become a promising technique for protein detection.
College of Science, University of Shanghai for Science and Technology, Shanghai 200093, People's Republic of China. Electronic address: anyarui@usst.edu.cn.
Yarui
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An
D000906:Antibodies / Q000737:chemistry / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000737:chemistry / Q000378:metabolism; D055664:Electrochemical Techniques; D006046:Gold / Q000737:chemistry* / Q000378:metabolism; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism; D056564:Sirtuin 1 / Q000032:analysis* / Q000378:metabolism; D014025:Titanium / Q000737:chemistry* / Q000378:metabolism
D000906:Antibodies; D003432:Cross-Linking Reagents; D011108:Polymers; C009495:titanium dioxide; D006046:Gold; D014025:Titanium; D006735:Horseradish Peroxidase; C447939:SIRT1 protein, human; D056564:Sirtuin 1
Electrochemical; Hyperbranched polymer; Immunoassay; SirT1; TiO(2)–Au nanocomposite