癌症诊断涉及多个步骤的过程。准确识别肿瘤、癌细胞的分期和发展对于选择最佳治疗方法以尽量减少疾病复发至关重要。量子点（QD）代表了分子检测和靶向肿瘤成像中一类令人兴奋的荧光纳米探针。在这项研究中，石墨烯量子点（GQD）是通过在高温下热解柠檬酸（CA）作为碳前体来合成的。首先使用物理（TEM 和 DLS）和光谱（荧光、FTIR 和 UV-Vis）方法对所得 GQD 的形态进行表征。接下来，在 SnCl2.2H2O 作为还原剂的存在下，在 95 至 100°C 之间制备了 99mTc 标记的 GQD。在动物模型中评估了放射性标记 GQD 作为 C6 胶质瘤肿瘤闪烁扫描新剂的生物分布和肿瘤靶向效率。此外，还测量了器官摄取、人血清白蛋白结合和肿瘤积累。TEM图像显示所制备的GQDs在直径6-9nm范围内呈相对均匀的尺寸分布，呈球形。放射性标记的 GQD 显示放射化学产率 >97% (n = 3)。通过在人血清中孵育，6 小时后几乎 15% 的 99mTc 标记的 GQD 被降解。胶质瘤C6大鼠异种移植模型1小时后的摄取量为每克注射剂量的1.10±0.36%。通过闪烁扫描成像观察肾脏、肠道和神经胶质瘤肿瘤部位。我们的数据表明，99mTc标记的GQD作为一种新的放射性示踪剂，可以有效地积聚在肿瘤部位，可以作为检测神经胶质瘤的放射性示踪剂。

Cancer diagnosis involves a multi-step process. Accurate identification of the tumor, staging and development of cancer cells is crucial for selecting optimal treatments to minimize disease recurrence. Quantum dots (QDs) represent an exciting class of fluorescent nanoprobes in molecular detection and targeted tumor imaging.In this study, graphene quantum dots (GQDs) were synthesized by pyrolysis of citric acid (CA) as a carbon precursor under high temperatures. The morphology of the obtained GQDs was first characterized using physical (TEM and DLS) and spectroscopic (fluorescence, FTIR and UV-Vis) methods. In the following,99mTc-labeled GQDs were prepared in the presence of SnCl2.2H2O as a reducing agent between 95 and 100 °C. The biodistribution and tumor targeting efficiency of radiolabeled GQDs as a novel agent for C6 glioma tumor scintigraphy in an animal model were evaluated. Furthermore, organ uptake, human serum albumin binding and tumor accumulation were measured.The TEM image of the prepared GQDs showed a relatively uniform size distribution in the range of diameter 6-9 nm and spherical shape. Radiolabeled GQDs showed a radiochemical yield of >97% (n = 3). Through incubation in human serum, almost 15% of 99mTc-labeled GQDs degraded after 6 h. The amount of uptake in xenograft models of glioma C6 rats was 1.10 ± 0.36% of injection dose per gram after 1 h. The kidneys, intestinal and glioma tumor sites were observed via scintigraphy imaging.Our data suggest that 99mTc-labeled GQDs, as a new radiotracer, efficiently accumulate in the tumor site and could be included as a radiotracer for detecting glioma tumors.