Preparation and evaluation of glutathione modified SiO2 @ Au as stationary phase in capillary liquid chromatography and pressurized capillary electrochromatography

Abstract

In order to improve the contents of -NH2 group on the surface of SiO2, polyethylenimine ( PEI) was introduced on the surface of SiO2 through Schiff Base reaction. Then self-assembled monolayer electroless plating (SAM-electroless plating) method was used to prepare SiO2 @ Au core-shell particles. During this process, two factors were discussed. They were the reaction pH in the SiO2 @ Au seed forming phase and the reaction volume of formaldehyde in the SiO2 @ Au seed growth phase. The scanning electronic microscopy (SEM) showed the coverage of Au was high and the dispersity was uniform after the optimizations. As we know, Au can coordinate with -SH group easily, so glutathione (GSH) can be bound on the surface of Au. In this study, GSH was bound on the surface of Au through the optimization of the reaction pH. The Fourier transform infrared spectrum showed that the GSH was bound on the surface of Au successfully at pH 3. At last, this packing material was packed into capillary column by slurry packing method to prepare SiO2 @ Au-GSH capillary columns, and the capillary liquid chromatography (cLC) mode was used to certify the hydrophilic property of this kind of column. In addition, this kind of column was certified to have a good separation ability of polar compounds in pressurized capillary electrochromatography (pCEC) mode.