Physics & Astronomy Faculty Publications
Document Type
Article
Publication Date
9-24-2025
Abstract
We report a rapid aqueous method for synthesizing monodisperse gold nanoparticles (AuNPs), employing 2-propynylamine as both an intrinsic reducing agent and a surface-stabilizing ligand. This self-mediated process—achieved in a single step—yields spherical AuNPs with an average diameter of 4.0 ± 1.0 nm and a well-defined localized surface plasmon resonance band centered at 520 nm. Acting as a bifunctional molecule, 2-propynylamine simultaneously reduces HAuCl4·3H2O to elemental gold and passivates the nanoparticle surface through coordination via the amine group, while preserving a terminal alkyne (–C≡CH) functionality. This reactive moiety remains exposed and chemically accessible, enabling post-synthetic modification through Cu(I)-catalyzed azide–alkyne cycloaddition. Control experiments using alternate milling times and vial composition confirmed the essential role of 2-propynylamine in mediating both reduction and surface functionalization. The resulting alkyne-functionalized AuNPs serve as versatile “click-ready” platforms for bioconjugation, sensing, and advanced material assembly. Overall, this scalable, green approach eliminates the need for external reducing or capping agents and provides a modular route to chemically addressable nanomaterials with tunable surface reactivity.
Recommended Citation
Garcia, Amber L., Brian S. Mitchell, Amanda Reusch, Mark J. Fink, Juan P. Hinestroza, Yelin Ko, and Julie P. Vanegas. "Click-Ready Gold Nanoparticles from Aqueous Mechanochemistry: 2-Propynylamine as a Reducing Agent and Surface Ligand." Materials 18, no. 19 (2025): 4470. https://doi.org/10.3390/ma18194470
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Publication Title
Materials
DOI
10.3390/ma18194470
Included in
Astrophysics and Astronomy Commons, Nanoscience and Nanotechnology Commons, Physics Commons
Comments
© 2025 by the authors.
Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).