The determination of ligand shell composition of bifunctional alkanethiol-capped gold nanoparticles using GC/MS/MS

A methodology for the determination of two-component alkylthiol ligand shell composition of 2 nm gold nanoparticles by GC/MS/MS is presented. Nanoparticles were prepared with ligand shells composed of 1-dodecanethiol and 11-mercapto-1-undecanol with reaction solution ratios of the OH-terminated component of 25, 50 and 75%. The nanoparticles were decomposed in the presence of iodine and the resulting disulphide mixtures were analysed by GC/MS/MS. An efficient calibration strategy is shown to be effective in providing results comparable to an established 1H-NMR analysis method, while minimizing thiol and nanoparticle consumption. The presented method provides an accessible and highly general option for the characterisation mixed monolayer-capped gold nanoparticles containing specialized ligands.