Issue 22, 2014

Surfactant-free nanoparticle–DNA complexes with ultrahigh stability against salt for environmental and biological sensing

Abstract

We report the development of surfactant free-gold nanoparticle (AuNP)–DNA complexes that remained stable in solutions with extremely high ionic strength, using seawater as a model solution. Although the stability of AuNPs can be increased to a certain degree by functionalizing negatively charged DNA strands on their surfaces, they still have limited stability in highly concentrated salt solutions. However, we found that AuNPs functionalized with poly-T bases have exceptional stability in high ionic strength solutions. For example, AuNPs functionalized with a 5T spacer remained highly stable in seawater, with no color change and no red-shift in absorbance spectra for up to 9 days. Using this surprising property of poly-T spacers, we prepared highly stable AuNP–DNA complexes containing random sequences by introducing 5T spacers on the random sequenced DNA strand. The random sequenced AuNP–DNA complexes remained stable in seawater, several molar concentrations of monovalent metal ion solutions (6.1 M Na+ or 4.8 M K+), and millimolar concentrations of diverse divalent metal ions. In addition, the highly stable AuNP–DNA complex maintained biological activity in seawater, which was demonstrated by complementary reaction and aptamer based biosensing. These results provide important insight into NP use for various applications under harsh biological and environmental conditions.

Graphical abstract: Surfactant-free nanoparticle–DNA complexes with ultrahigh stability against salt for environmental and biological sensing

Supplementary files

Article information

Article type
Paper
Submitted
15 Jul 2014
Accepted
01 Sep 2014
First published
01 Sep 2014

Analyst, 2014,139, 5936-5944

Author version available

Surfactant-free nanoparticle–DNA complexes with ultrahigh stability against salt for environmental and biological sensing

J. H. Heo, H. H. Cho and J. H. Lee, Analyst, 2014, 139, 5936 DOI: 10.1039/C4AN01271B

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements