GRAPHENE QUANTUM DOTS-GADOLINIUM ION CHELATE AS MAGNETIC RESONANCE IMAGING CONTRAST AGENT AND PREPARATION METHOD THEREOF

摘要

A graphene quantum dots-gadolinium ion chelate (Gd@GQDs) nanomaterial with hydrophilic groups on the surface has a preparation method that includes: preparing graphene oxide by using a Hummers method; subsequently, subjecting the graphene oxide to heating, oxidation, and purification to obtain pure graphene quantum dots; and finally, chelating the graphene quantum dots with Gd3+ to form stable Gd@GQDs. The Gd@GQDs is easily dispersed in water, phosphate buffered solution (PBS), biological medium and other aqueous system, has good biocompatibility and low cytotoxicity, shows an excellent T1-weighted contrast performance in a 1.5-Tesla magnetic resonance testing system, and has a relaxation rate r1 as high as 72 mM−1s−1, the value of r1 being 20 times higher than that of the current commercial T1-weighted magnetic resonance imaging contrast agent Gd-DTPA.