Monofunctionat gold nanopartictes prepared via a noncovalent-interaction-based solid-phase modification approach

The solid-phase preparation of monofunctionalized gold nanoparticles using noncovalent interaction was presented. The solid support used in this preparation was amino-group functionalized silica gel. The bifunctional ligands, 11-mercaptoundecanoic acid (MUA), were then loaded onto the support directly as a result of the electrostatic interaction of the positively charged amino groups from the silica gel with the negatively charged carboxylic acid groups from the MUA ligands. The nanoparticle was purified by washing with petroleum ether, followed by gel permeation chromatography to give 60-90 % yield of monocarboxyl gold nanoparticles. In addition to amino-group-functionalized silica gel, Rink resin, an amino-group-functionalized resin consisting of a lightly crosslinked polystyrene matrix, was also used for the surface functionalization of the gold nanoparticles. The most reliable method of determining the relative purity of the monofunctional nanoparticle product is by conducting a dimine-coupling reaction with the solid-phase-modified nanoparticles and using TEM to analyze the coupled product.