Toward Fast and Quantitative Modification of Large Gold Nanoparticles by Thiolated DNA: Scaling of Nanoscale Forces, Kinetics, and the Need for Thiol Reduction

This document is the Accepted Manuscript version of a Published Work that appeared in final form in The Journal of Physical Chemistry copyright © American Chemical Society after peer review and technical editing by publisher. To access the final edited and published work see Zhang, X., Gouriye, T., Göeken, K., Servos, M. R., Gill, R., & Liu, J. (2013). Toward Fast and Quantitative Modification of Large Gold Nanoparticles by Thiolated DNA: Scaling of Nanoscale Forces, Kinetics, and the Need for Thiol Reduction. The Journal of Physical Chemistry C, 117(30), 15677–15684. https://doi.org/10.1021/jp403946xWe have recently reported on the fast and quantitative adsorption of DNA to 13 nm gold nanoparticles (AuNPs) at pH 3. This is in contrast to most traditional methods at neutral pH, where the adsorption is both slow and requires high excess of DNA. Direct application of our protocol to large particles in many cases did not result in particles that are stable at high (0.3 M) salt, and high excess of DNA was still required for the formation of stable particles. In this work, we investigate the reasons for this limitation on the basis of kinetics and colloidal stability. On the basis of our investigation, fast and quantitative modification of large AuNPs is still possible, either by working at high particle concentration, or by using sonication. As we have shown that fast quantitative modification of large particles is possible, the preparation step of reduction and purification of the thiolated DNA becomes the rate limiting step in the whole AuNP-DNA conjugate protocol. However, we show that this step is unnecessary when using our current protocol.University of Waterloo || Canadian Foundation for Innovation || Natural Sciences and Engineering Research Council || Canadian Institutes of Health Research || Ontario Ministry of Research and Innovation || Netherlands Technology Foundation || STW-project no. 1181