Label-Free and Ultrasensitive Electrochemical DNA Biosensor based on Urchinlike Carbon Nanotube-Gold Nanoparticle Nanoclusters

Author

Shuo Han
Wenyan Liu, Missouri University of Science and TechnologyFollow
Ming Zheng
Risheng Wang, Missouri University of Science and TechnologyFollow

Abstract

Nanomaterials have been extensively utilized in biosensing systems for highly sensitive and selective detection of a variety of biotargets. In this work, a facile, label-free, and ultrasensitive electrochemical DNA biosensor has been developed, based on "urchinlike"carbon nanotube-gold nanoparticle (CNT-AuNP) nanoclusters, for signal amplification. Specifically, electrochemical polymerization of dopamine (DA) was employed to modify a gold electrode for immobilization of DNA probes through the Schiff base reaction. Upon sensing the target nucleic acid, the dual-DNA (reporter and linker) functionalized AuNPs were introduced into the sensing system via DNA hybridization. Afterward, the end-modified single-wall carbon nanotubes with DNA (SWCNT-DNA) were attached to the surface of the AuNPs through linker-DNA hybridization that formed 3D radial nanoclusters, which generated a remarkable electrochemical response. Because of the larger contact surface area and super electronic conductivity of CNT-AuNP clusters, this novel designed 3D radial nanostructure exhibits an ultrasensitive detection of DNA, with a detection limit of 5.2 fM (a linear range of from 0.1 pM to 10 nM), as well as a high selectivity that discriminates single-mismatched DNA from fully matched target DNA under optimal conditions. This biosensor, which combines the synergistic properties of both CNTs and AuNPs, represents a promising signal amplification strategy for achieving a sensitive biosensor for DNA detection and diagnostic applications.

Recommended Citation

S. Han et al., "Label-Free and Ultrasensitive Electrochemical DNA Biosensor based on Urchinlike Carbon Nanotube-Gold Nanoparticle Nanoclusters," Analytical Chemistry, vol. 92, no. 7, pp. 4780 - 4787, American Chemical Society (ACS), Apr 2020.

The definitive version is available at https://doi.org/10.1021/acs.analchem.9b03520

Department(s)

Chemistry

Comments

National Science Foundation, Grant CCF-1814797

International Standard Serial Number (ISSN)

0003-2700; 1520-6882

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2020 American Chemical Society (ACS), All rights reserved.

Publication Date

07 Apr 2020