Send to

Choose Destination
Biosens Bioelectron. 2013 May 15;43:372-8. doi: 10.1016/j.bios.2012.12.051. Epub 2012 Dec 31.

Multilayer hemin/G-quadruplex wrapped gold nanoparticles as tag for ultrasensitive multiplex immunoassay by chemiluminescence imaging.

Author information

State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093, PR China.


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.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center