Triazole Cycloaddition as a General Route for Functionalization of Au Nanoparticles

Triazole formation by 1,3-dipolar cycloaddition reactions, “click” chemistry, has been used to functionalize the surfaces of Au nanoparticles. Au particle samples were first synthesized through standard procedures, the methyl-terminated chains partially exchanged with ω-bromo-functionalized thiol, and the Br termini converted to azides by reaction with NaN3. These particles were then reacted with a series of alkynyl derivatized small molecules in nonpolar solutions, which led to their attachment through the formation of a 1,2,3-triazole ring, confirmed through NMR and IR spectroscopies. Click reactions were used to impart chemical functionality to the Au particles, which is assessed using fluorescence spectroscopy and cyclic voltammetry.