▎ 摘　　要

In this work, the synthesis of graphene oxide grafted poly citric acid-gamma-Fe2O3 nanocomposite (GO-g-PCA/gamma-Fe2O3) with a simple method and its application as a useful negative contrast agent in magnetic resonance imaging was studied. GO was prepared by Mildly method and polymerized with citric acid to produce GO-g-PCA. gamma-Fe2O3 nano particles were synthesized by co-precipitation method in the size distribution range of 10-25 nm with saturation magnetization (M-s) 21 emu g(-1). The nanoparticles encapsulated on GO-g-PCA to produce nanocomposite that showed excellent stability, extra dispersibility, and good superparamagnetic properties with M-s 14 emu g(-1). This nanocomposite provided significant contrast enhancement effect in T-2 and T-2*-weighted images with r(2) and r(2)* values 125.63 and 280.85 mM(-1) s(-1) respectively at 3.0 T. The cytotoxicity evaluation showed no cell toxicity in HCT-116 cell lines even at a high concentration up to 141 mu g mL(-1) after being treated for 24 h by MIT assay test method. (C) 2019 Elsevier B.V. All rights reserved.