The excellent photoluminescent properties of Fe₃O₄-graphene quantum dots (Fe₃O₄/GQD) nanoparticles prepared at 30 and 90 °C have made them as promising optical probes for imaging. Herein, the cytotoxicity of GQD and Fe₃O₄/GQD nanoparticles in L929 cells was investigated using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium Bromide] assay. The cellular apoptosis or necrosis was then evaluated by flow cytometry analysis. The Fe₃O₄/GQD nanoparticles were characterized by transmission electron microscopy (TEM), Raman spectroscopy (Raman), Fourier-transform infrared spectroscopy (FT-IR), photoluminescence (PL). Characterization results obtained, clearly show that Fe₃O₄/GQD nanoparticles at 30 and 90 °C has been successfully prepared. Water solubility and excellent photostability along with low cytotoxicity of Fe₃O₄/GQD nanoparticles prepared at 30 and 90 °C were manifested as a remarkable bioimaging material.

在30和90°C下制备的Fe ₃ O _4-石墨烯量子点（Fe ₃ O ₄ / GQD）纳米粒子具有出色的光致发光性能，使其成为有希望的成像光学探针。在本文中，使用MTT [3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四唑溴化物]测定法研究了G929和Fe ₃ O ₄ / GQD纳米颗粒在L929细胞中的细胞毒性。然后通过流式细胞术分析评估细胞凋亡或坏死。铁₃ O ₄/ GQD纳米粒子通过透射电子显微镜（TEM），拉曼光谱（Raman），傅里叶变换红外光谱（FT-IR），光致发光（PL）进行表征。获得的表征结果清楚地表明，已成功制备了在30和90°C下的Fe ₃ O ₄ / GQD纳米颗粒。在30和90°C下制备的Fe ₃ O ₄ / GQD纳米颗粒的水溶性和优异的光稳定性以及低的细胞毒性被证明是一种出色的生物成像材料。