Zhou, Jingfang Sedev, Rossen Beattie, David Ralston, John Light-Induced Aggregation of Colloidal Gold Nanoparticles Capped by Thymine Derivatives The colloid stability of thymine-coated gold nanoparticles under light irradiation as a function of particle size, surface charge, and exposure time was investigated in alkaline, aqueous solutions as well as in a 0.5 vol % of DMF in H<sub>2</sub>O mixture. With increasing exposure to light irradiation at 280 nm, more and more particles coagulated. Light-induced aggregation of colloidal gold nanoparticles was attributed to reorientation of thymine terminal groups tethered on gold particle surfaces. A smaller particle size and negatively charged surface reduced the rate of photodimerization or even inhibited the photoreaction. UV−vis and FTIR spectroscopy confirmed the photodimerization of terminal thymine molecules under 280 nm light irradiation. The reaction kinetics of thymine photodimerization appears to be a combination of first-order reactions, each having different rates, reflecting the inhomogeneity and high curvature of the gold nanoparticle surfaces. UV;light irradiation;H 2O mixture;terminal thymine molecules;DMF;gold nanoparticle surfaces;FTIR;thymine terminal groups;photodimerization;particle size;gold particle surfaces;exposure;Thymine DerivativesThe colloid stability;280 nm light irradiation;Colloidal Gold Nanoparticles Capped 2008-05-06
    https://acs.figshare.com/articles/journal_contribution/Light_Induced_Aggregation_of_Colloidal_Gold_Nanoparticles_Capped_by_Thymine_Derivatives/2940634
10.1021/la703746w.s006