▎ 摘　　要

In this study synthesis of graphene oxide-poly citric acid/MnCe0.5Fe1.5O4 nanoferrofluid with a simple method and its ability for enhancing the contrast of magnetic resonance images was reported. The co-precipitation method has been used for the production of MnCe0.5Fe1.5O4 nanoparticles with a size distribution of 25-40 nm, which has shown a very good superparamagnetic property with saturation magnetization (M-s) 53.6 emu g(-1). Graphene oxide (GO) was prepared by a modified Hummers method and polymerized with citric acid to produce GO-PCA. The nanoparticles were loaded on the GO-PCA surface to produce nanoferrofluid that showed excellent colloidal stability, extra dispersibility, and good magnetic properties with M-s equal to 47.8 emu g(-1). This nanoferrofluid has an increased effect on the contrast of T-2 and T-2(*)-weighted images, with the values 109.15 and 180.23 mM(-1) s(-1) for r(2) and r(2)(*), respectively at 3.0 T. The cellular uptake evaluation revealed adequate uptake for HeLa cell lines.