Key Laboratory of Radiological Protection and Nuclear Emergency, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, Beijing 100088, China; Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Beijing Institute of Metrology, Beijing 100029, China.
Talanta. 2018 Sep 1;187:308-313. doi: 10.1016/j.talanta.2018.05.012. Epub 2018 May 3.
To develop a simple and sensitive sensor for gamma radiation is of great importance not only for public safety, but also for rational utilization of ionizing radiation. In this study, a simple and sensitive method for colorimetric detection of low dose gamma radiation has been developed based on the single-strand DNA modified AuNPs (ssDNA-AuNPs), which were synthesized by immobilizing the sulfhydryl ssDNA on the surface of AuNPs. After the gamma radiation, the colors of ssDNA-AuNPs changed from wine-red to blue-purple gradually, and this can be easily distinguished by the naked eyes. Over a range from 0 to 30 Gy, a good linear relationship between the ratio of absorbance at 625 nm to that at 521 nm (A/A) in the UV-vis spectrum and radiation dose was obtained. The detection limit was as low as 0.5 Gy. The colorimetric mechanism was ascribed to the generation of hydroxyl radical during the gamma radiation. As a result, ssDNA was cut off and released from the AuNPs. Then the salt effect caused the aggregation leading to the distinct color change. The capability of the method has also been demonstrated for anti-radiation efficiency comparison of different radioprotectors. In addition, lymphocytes irradiation expriment indicated that the ssDNA-AuNPs prepared in this work can be successfully used for an indicator during blood irradiation to avoid transfusion associated graft vs. host disease (TA-GVHD).
开发用于伽马辐射的简单且灵敏的传感器不仅对公共安全很重要，而且对电离辐射的合理利用也很重要。在本研究中，基于单链 DNA 修饰的金纳米粒子（ssDNA-AuNPs），我们开发了一种简单且灵敏的用于低剂量伽马辐射比色检测的方法。ssDNA-AuNPs 是通过将巯基 ssDNA 固定在 AuNPs 表面而合成的。经过伽马辐射后，ssDNA-AuNPs 的颜色逐渐从酒红色变为蓝紫色，这可以通过肉眼轻松区分。在 0 到 30Gy 的范围内，紫外可见光谱中 625nm 处吸光度与 521nm 处吸光度的比值（A/A）与辐射剂量之间呈现良好的线性关系。检测限低至 0.5Gy。比色机理归因于伽马辐射过程中羟基自由基的产生。结果，ssDNA 被切断并从 AuNPs 上释放出来。然后，盐效应导致聚集，从而导致明显的颜色变化。该方法的性能还已被证明可用于比较不同辐射防护剂的抗辐射效率。此外，淋巴细胞照射实验表明，本工作中制备的 ssDNA-AuNPs 可成功用于血液照射的指示剂，以避免输血相关移植物抗宿主病（TA-GVHD）。
