Zhao Lin, Wang Yingmin, Li Yan
School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Nanomaterials (Basel). 2019 Nov 29;9(12):1708. doi: 10.3390/nano9121708.
Antioxidants can reduce or inhibit damage such as oxidative decay caused by elevated levels of free radicals. Therefore, pursuing antioxidants with excellent properties has attracted more and more attention. Graphene quantum dots (GQDs) are considered a promising material because of their good free radical scavenging activity, low toxicity, and excellent water solubility. However, their scavenging efficiency, antioxidant mechanism, and effective control methods need to be improved. Herein, in order to further reveal the antioxidant mechanism of GQDs, the role of electrolytes in improving the antioxidant activity of GQDs is explored. In addition, 1,1-diphenyl-2-picrazine (DPPH∙), hydroxyl (∙OH), and superoxide (∙O) free radicals are used to evaluate the antioxidant activity of the as-prepared GQDs. Combined with transmission electron microscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, and cyclic volt-ampere characteristic curves, the effects of an electrolytic environment on the surface functional groups, charge transfer capability, and defect states of GQDs are obtained. The antioxidant mechanism of GQDs and how to improve their antioxidant activity are further elucidated.
抗氧化剂可以减少或抑制诸如由自由基水平升高引起的氧化衰变等损伤。因此，寻找具有优异性能的抗氧化剂越来越受到关注。石墨烯量子点（GQDs）因其良好的自由基清除活性、低毒性和出色的水溶性而被认为是一种很有前景的材料。然而，它们的清除效率、抗氧化机制和有效控制方法仍有待改进。在此，为了进一步揭示GQDs的抗氧化机制，探索了电解质在提高GQDs抗氧化活性中的作用。此外，使用1,1-二苯基-2-苦基肼（DPPH∙）、羟基（∙OH）和超氧阴离子（∙O）自由基来评估所制备的GQDs的抗氧化活性。结合透射电子显微镜、傅里叶变换红外光谱、拉曼光谱和循环伏安特性曲线，获得了电解环境对GQDs表面官能团、电荷转移能力和缺陷状态的影响。进一步阐明了GQDs的抗氧化机制以及如何提高其抗氧化活性。
