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Polarity Control for Nonthiolated DNA Adsorption onto Gold Nanoparticles

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Liu_Juewen(23)-s.pdf (1007.5 KB)

Date

2013-05-21

Authors

Zhang, Xu
Liu, Biwu
Servos, Mark R.
Liu, Juewen

Journal Title

Journal ISSN

Volume Title

Publisher

American Chemical Society

Abstract

Gold nanoparticles (AuNPs) functionalized with thiolated DNA have enabled many studies in nanoscience. The strong thiol/gold affinity and the nanoscale curvature of AuNPs allow the attached DNA to adapt an upright conformation favorable for hybridization. Recently, it has been shown that nonthiolated DNA can also be attached via DNA base adsorption. Without a thiol label, both ends of the DNA and even internal bases could be adsorbed, decreasing the specificity of subsequent molecular recognition reactions. In this work, we employed a modular sequence design approach to systematically study the effect of DNA sequence on adsorption polarity. A block of poly adenine (poly-A) could be used to achieve a high density of DNA attachment. When the poly-A block length is short (e.g., below 5–7), the loading was independent of the block length, and the conjugate cannot hybridize to its cDNA effectively, suggesting a random attachment controlled by adsorption kinetics. Increasing the block length leads to reduced capacity but improved hybridization, suggesting that more DNA with the desired conformation was adsorbed due to the thermodynamic effects of poly-A binding. The design can be further improved by including capping sequences rich in T or G. Finally, a more general double-stranded DNA approach was described to be suitable for DNA that cannot satisfy the above-mentioned design requirements.

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 Zhang, X., Liu, B., Servos, M. R., & Liu, J. (2013). Polarity Control for Nonthiolated DNA Adsorption onto Gold Nanoparticles. Langmuir, 29(20), 6091–6098. https://doi.org/10.1021/la400617u

Keywords

DNA, gold nanoparticles, adsorption

LC Keywords

Citation

URI

http://dx.doi.org/10.1021/la400617u
 http://hdl.handle.net/10012/11385

Collections

Waterloo Research
Chemistry
Waterloo Institute for Nanotechnology