Journal
BIOSENSORS & BIOELECTRONICS
Volume 54, Issue -, Pages 365-371Publisher
ELSEVIER ADVANCED TECHNOLOGY
DOI: 10.1016/j.bios.2013.11.014
Keywords
Impedimetric immunosensor; Catalytic precipitation; DNAzyme; Prostate specific antigen; Triple signal amplification; Gold-palladium hybrid nanostructures
Categories
Funding
- 973 National Basic Research Program of China [2010CB732403]
- NSFC of China [21075019, 41176079]
- NSF of Fujian Province [2011J06003]
- Research Fund for the Doctoral Program of Higher Education of China [20103514120003]
- Program for Changjiang Scholars and Innovative Research Team in University [IRT1116]
Ask authors/readers for more resources
A highly sensitive and selective impedimetric immunosensor with triple signal amplification was designed for ultrasensitive detection of prostate-specific antigen (PSA) by using anti-PSA antibody and DNAzyme-functionalized gold-palladium hybrid nanotags (Ab(2)-AuPd-DNA). The signal was amplified based on the Ab(2)-AuPd-DNA toward the catalytic precipitation of 4-choloro-1-naphthol (4-CN). DNAzyme (as a kind of peroxidase mimic) could catalyze the oxidation of 4-CN, whilst AuPd hybrid nanostructures could not only provide a large surface coverage for immobilization of biomolecules but also promote 4-CN oxidation to some extent. The produced insoluble benzo-4-chlorohexadienone via 4-CN was coated on the electrode surface, and hindered the electron transfer between the solution and the electrode, thereby increasing the Faradaic impedance of the base electrode. Three labeling strategies including Ab(2)-AuNP, Ab(2)-AuPd and Ab(2)-AuPd-DNA were investigated for determination of PSA, and improved analytical features were obtained with the Ab(2)-AuPd-DNA strategy. Under optimal conditions, the dynamic concentration range of the impedimetric immunosensor spanned from 1.0 pg mL(-1) to 50 ng mL(-1) PSA with a detection limit of 0.73 pg mL(-1). Intra- and inter-assay coefficients of variation were below 8.5% and 9.5%, respectively. Importantly, no significant differences at the 0.05 significance level were encountered in the analysis of 6 clinical serum specimens and 6 diluted standards between the impedimetric immunosensor and the commercialized electrochemiluminescent method for PSA detection. (C) 2013 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available