Ciotta Erica, Paoloni Stefano, Richetta Maria, Prosposito Paolo, Tagliatesta Pietro, Lorecchio Chiara, Venditti Iole, Fratoddi Ilaria, Casciardi Stefano, Pizzoferrato Roberto
Department of Industrial Engineering, University of Rome Tor Vergata, 00133 Rome, Italy.
Department of Industrial Engineering INSTM and CiMER, University of Rome Tor Vergata, 00133 Rome, Italy.
Sensors (Basel). 2017 Nov 14;17(11):2614. doi: 10.3390/s17112614.
A novel type of graphene-like quantum dots, synthesized by oxidation and cage-opening of C buckminsterfullerene, has been studied as a fluorescent and absorptive probe for heavy-metal ions. The lattice structure of such unfolded fullerene quantum dots (UFQDs) is distinct from that of graphene since it includes both carbon hexagons and pentagons. The basic optical properties, however, are similar to those of regular graphene oxide quantum dots. On the other hand, UFQDs behave quite differently in the presence of heavy-metal ions, in that multiple sensitivity to Cu, Pb and As(III) was observed through comparable quenching of the fluorescent emission and different variations of the transmittance spectrum. By dynamic light scattering measurements and transmission electron microscope (TEM) images we confirmed, for the first time in metal sensing, that this response is due to multiple complexation and subsequent aggregation of UFQDs. Nonetheless, the explanation of the distinct behaviour of transmittance in the presence of As(III) and the formation of precipitate with Pb require further studies. These differences, however, also make it possible to discriminate between the three metal ions in view of the implementation of a selective multiple sensor.
一种通过对C60富勒烯进行氧化和开笼反应合成的新型类石墨烯量子点，已被作为一种用于重金属离子的荧光和吸收探针进行了研究。这种展开式富勒烯量子点（UFQDs）的晶格结构与石墨烯不同，因为它同时包含碳六边形和五边形。然而，其基本光学性质与普通氧化石墨烯量子点相似。另一方面，UFQDs在重金属离子存在下表现出截然不同的行为，即通过荧光发射的可比猝灭和透射光谱的不同变化，观察到对铜、铅和砷（III）具有多重敏感性。通过动态光散射测量和透射电子显微镜（TEM）图像，我们首次在金属传感中证实，这种响应是由于UFQDs的多重络合和随后的聚集。尽管如此，对于在砷（III）存在下透射率的独特行为以及与铅形成沉淀的解释仍需要进一步研究。然而，这些差异也使得鉴于选择性多重传感器的实现，能够区分这三种金属离子。
