Preparation of diazoresin/graphene oxide covalent coated capillary for separation of proteins by capillary electrophoresis

Abstract

Protein adsorption on the inner surface of capillary is the main reason for the poor separation performance of capillary electrophoresis. Currently, many ways have been reported to inhibit protein adsorption, while they have numerous disadvantages, such as complicated, toxic and unstable. Here, by using photosensitive diazoresin (DR) as coupling agents and graphene oxide (GO) as coating, we found a simple, economic and environmental friendly approach to inhibit protein adsorption. Through layer by layer (LBL) self-assembly technique and unique photochemistry reaction of DR, a stable and efficient capillary coating could be obtained. The bare capillary, non-covalently GO coated capillary and covalently GO coated capillary were all characterized. Results indicated that the DR/GO covalently linked capillary coatings showed great separation performance of proteins with excellent stability and repeatability. Compared with bare capillary and non-covalent, better separation efficiency was achieved by covalent GO capillary column.