National Hellenic Research Foundation, Theoretical and Physical Chemistry Institute, 48 Vassileos Contantinou Avenue, Athens 11635, Greece.
Chemistry. 2013 Jul 8;19(28):9286-90. doi: 10.1002/chem.201300806. Epub 2013 May 31.
Stable dispersions of exfoliated graphene in aqueous media with the aid of the amphiphilic block copolymer poly(isoprene-b-acrylic acid) (PI-b-PAA), in the form of its anion, were used to electrostatically bind cationic 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphine tetra(p-toluenesulfonate) (H2P(4+)). A new graphene/PI-b-PAA(-)-H2P(4+) ensemble was formed and examined by dynamic light scattering, UV/Vis and fluorescence emission spectroscopy. The efficient fluorescence quenching of H2P(4+) in the graphene/PI-b-PAA(-)-H2P(4+) ensemble was probed by using steady-state and time-resolved photoluminescence, suggesting that electron/energy-transfer phenomena occur within the nanoensemble. Blank experiments validated the concept of electrostatic interactions that govern the formation of graphene/PI-b-PAA(-)-H2P(4+) ensemble, which signified the importance of graphene as an electron acceptor toward the preparation of some new donor-acceptor systems. Finally, kinetic analysis of the lifetime profiles of the fluorescence emission gave information regarding the quenching rate constant and quantum yield of the singlet excited state of H2P(4+) in the graphene/PI-b-PAA(-)-H2P(4+) ensemble.
在两亲嵌段共聚物聚异戊二烯-b-丙烯酸（PI-b-PAA）的帮助下，将剥离的石墨烯在水介质中稳定分散，形成其阴离子，用于静电结合阳离子 5,10,15,20-四（1-甲基-4-吡啶𬭩）卟啉四（对甲苯磺酸盐）（H2P(4+)）。形成了一种新的石墨烯/PI-b-PAA(-)-H2P(4+) 复合物，并通过动态光散射、UV/Vis 和荧光发射光谱进行了检查。通过稳态和时间分辨光致发光研究了 H2P(4+) 在石墨烯/PI-b-PAA(-)-H2P(4+) 复合物中的有效荧光猝灭，表明在纳米复合物内发生了电子/能量转移现象。空白实验验证了控制石墨烯/PI-b-PAA(-)-H2P(4+)复合物形成的静电相互作用的概念，这表明石墨烯作为电子受体在制备一些新的供体-受体系统方面的重要性。最后，荧光发射寿命曲线的动力学分析提供了有关石墨烯/PI-b-PAA(-)-H2P(4+)复合物中 H2P(4+)的单重激发态的猝灭速率常数和量子产率的信息。
