کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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866867 | 1470988 | 2013 | 7 صفحه PDF | دانلود رایگان |
A multilayer hemin/G-quadruplex DNAzyme wrapped gold nanoparticle (M-DNAzyme/AuNP) tag was designed for ultrasensitive chemiluminescence (CL) imaging. By combining with a disposable protein array, an ultrasensitive and high-throughput multiplex CL immunoassay method was proposed for simultaneous detection of four cancer biomarkers. The M-DNAzyme/AuNP tag was prepared by assembling high ratio of alkylthiol-capped signal DNA containing multiple G-quadruplex sequences to biotinylated DNA on AuNPs and then reacting with hemin to form multilayer hemin/G-quadruplex DNAzyme units. It could be bound to the biotinylated secondary antibody of sandwich immunocomplex by biotin–streptavidin conjugation to catalyze a CL reaction on a protein array, which produced strong CL emission. Under optimal conditions, the CL signals could be simultaneously collected by a charge-coupled device for ultrasensitive multiplex CL imaging of cancer biomarkers. Using α-fetoprotein, human chorionic gonadotrophin-β, carcinoma antigen 125, and carcinoembryonic antigen as model analytes, the proposed immunoassay method showed high sensitivities and wide linear ranges in a simple, cheap and high throughput way. The M-DNAzyme/AuNP as a universal signal tag as well as the protein chip could be suitable for mass production for economical, portable and multianalyte assay, showing a promising potential in application to clinic and other relative fields.
► An ultrasensitive high-throughput immunoassay method is proposed by CL imaging.
► A multilayer DNAzyme wrapped tag is simply prepared for signal amplification.
► The tag can serve as a universal signal label for multiple analytes.
► The method can simultaneously detect four cancer biomarkers down to femtomolar level.
Journal: Biosensors and Bioelectronics - Volume 43, 15 May 2013, Pages 372–378