▎ 摘　　要

NOVELTY - A gadolinum-diethylenetriamine pentaacetic-graphene oxide (GO-Gd-DTPA) complex, formed by an ester bond of graphene oxide (GO) and gadopentetic acid (Gd-DTPA), is new. USE - For forming MRI contrast agent composition (claimed). ADVANTAGE - The GO-Gd-DTPA complex is useful as MRI contrast agent as it does not cause cellular toxicity and stably exists in body, due to high dispersibility in aqueous solution compared to conventional MRI contrast agents. In order to prepare complex which does not cause cellular toxicity and can be stably dispersed in body, GO is bonded to Gd-DTPA i.e. commonly-used gadolinium complex, where GO is water soluble and has low toxicity. Further, graphene oxide is advantageous in that it can be produced in large quantities in environment-friendly method. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for method for preparing the GO-Gd-DTPA complex.