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Cation-Size-Dependent DNA Adsorption Kinetics and Packing Density on Gold Nanoparticles: An Opposite Trend

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Liu_Juewen(20)-s.pdf (546.01 KB)

Date

2014-11-11

Authors

Liu, Biwu
Kelly, Erin Y.
Liu, Juewen

Journal Title

Journal ISSN

Volume Title

Publisher

American Chemical Society

Abstract

The property of DNA is strongly influenced by counterions. Packing a dense layer of DNA onto a gold nanoparticle (AuNP) generates an interesting colloidal system with many novel physical properties such as a sharp melting transition, protection of DNA against nucleases, and enhanced complementary DNA binding affinity. In this work, the effect of monovalent cation size is studied. First, for free AuNPs without DNA, larger group 1A cations are more efficient in inducing their aggregation. The same trend is observed with group 2A metals using AuNPs capped by various self-assembled monolayers. After establishing the salt range to maintain AuNP stability, the DNA adsorption kinetics is also found to be faster with the larger Cs+ compared to the smaller Li+. This is attributed to the easier dehydration of Cs+, and dehydrated Cs+ might condense on the AuNP surface to reduce the electrostatic repulsion effectively. However, after a long incubation time with a high salt concentration, Li+ allows ∼30% more DNA packing compared to Cs+. Therefore, Li+ is more effective in reducing the charge repulsion among DNA, and Cs+ is more effective in screening the AuNP surface charge. This work suggests that physicochemical information at the bio/nanointerface can be obtained by using counterions as probes.

Description

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Langmuir, copyright © American Chemical Society after peer review and technical editing by publisher. To access the final edited and published work see Liu, B., Kelly, E. Y., & Liu, J. (2014). Cation-Size-Dependent DNA Adsorption Kinetics and Packing Density on Gold Nanoparticles: An Opposite Trend. Langmuir, 30(44), 13228–13234. https://doi.org/10.1021/la503188h

Keywords

adsorption, DNA, gold nanoparticles

LC Keywords

Citation

URI

http://dx.doi.org/10.1021/la503188h
 http://hdl.handle.net/10012/11372

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Waterloo Research
Chemistry
Waterloo Institute for Nanotechnology