(253f) Functionalizing Gold Nanoparticles with Short Alkylamine Ligands Via Phase Transfer

Aqueous citrate-stabilized gold nanoparticles (Au NPs) cannot be directly transferred from water to an immiscible organic solution using short alkane ligands. In this study, we show an effective method to modify Au NP surfaces with short alkylamines based on an indirect phase transfer protocol. Briefly, hexane, alkylamine, and acetone were added to aqueous citrate-stabilized Au NPs to form a film at the system interfaces. The liquid phases were readily removed and then Au NPs were able to redisperse into tetrahydrofuran (THF). Au NP surfaces were successfully modified with alkylamines, as can be proven by Fourier transform infrared - attenuated total reflectance spectroscopy (FTIR-ATR). The size and shape of the transferred Au NPs were characterized by transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS). In addition, the short amine-protected Au NPs in THF can stay stable for at least 27 days. This approach provides a convenient and practical method to modify the Au NP surfaces with short alkyl ligands easily, rapidly, and efficiently, thus having a great potential in facilitating the fabrication of printed flexible electronics, electrical relays, and coupled electronic/photonic computing devices.