Visible-Light Photocatalyzed Cross-Linking of Diacetylene Ligands by Quantum Dots to Improve Their Aqueous Colloidal Stability
Document Type
Article - Abstract Only
Publication Date
2014
Keywords
Quantum dots, Electromagnetic radiation, Ligands, Fluorescence, Nucleic acid structure
Abstract
Ligand cross-linking is known to improve the colloidal stability of nanoparticles, particularly in aqueous solutions. However, most cross-linking is performed chemically, in which it is difficult to limit interparticle cross-linking, unless performed at low concentrations. Photochemical cross-linking is a promising approach but usually requires ultraviolet (UV) light to initiate. Using such high-energy photons can be harmful to systems in which the ligand–nanoparticle bond is fairly weak, as is the case for the commonly used semiconductor quantum dots (QDs). Here, we introduce a novel approach to cross-link thiolated ligands on QDs by utilizing the photocatalytic activity of QDs upon absorbing visible light. We show that using visible light leads to better ligand cross-linking by avoiding the problem of ligand dissociation that occurs upon UV light exposure. Once cross-linked, the ligands significantly enhance the colloidal stability of those same QDs that facilitated cross-linking.
Citation
Götz, M. G., Takeuchi, H., Goldfogel, M. J., Warren, J. M., Fennel, B. D., & Heyes, C. D. (2014). Visible-Light Photocatalyzed Cross-Linking of Diacetylene Ligands by Quantum Dots to Improve Their Aqueous Colloidal Stability. Journal of Physical Chemistry, 118 (49), 14103-14109. https://doi.org/10.1021/jp505340c
Comments
Principal Investigator: Colin Heyes
Acknowledgements: C.D.H. would like to thank the NSF (CHE-1255440), NIH (R21 EB009802-01 and COBRE P30 GM103450), and the Arkansas Biosciences Institute for financial support. M.G.G. would like to thank the NSF (CHE-MRI-0922775) for financial support.