| Autor: |
Baggio AR; Laboratory of Research on Polymers and Nanomaterials, Institute of Chemistry , University of Brasilia , Brasília DF 70904-970 , Brazil., Santos MSC; Institute of Biology , University of Brasília , Brasilia DF 70919-970 , Brazil., Souza FHV; Institute of Biology , University of Brasília , Brasilia DF 70919-970 , Brazil.; College of Ceilândia , University of Brasilia , Brasilia DF 72220-275 , Brazil., Nunes RB; Institute of Physics , University of Brasilia , Brasilia DF 70910-900 , Brazil., Souza PEN; Institute of Physics , University of Brasilia , Brasilia DF 70910-900 , Brazil., Báo SN; Institute of Biology , University of Brasília , Brasilia DF 70919-970 , Brazil., Patrocinio AOT; Laboratory of Photochemistry and Materials Science, Institute of Chemistry , Federal University of Uberlandia , Uberlandia , Brazil.; Institute of Technical Chemistry , Leibniz University Hannover , Hannover , Germany., Bahnemann DW; Institute of Technical Chemistry , Leibniz University Hannover , Hannover , Germany.; Laboratory of 'Photoactive Nanocomposite Materials' , Saint-Petersburg State University , Saint-Petersburg , Russia., Silva LP; Embrapa Genetic Resources and Biotechnology, PBI , Laboratory of Nanobiotechnology (LNANO) , Brasília DF 70770-917 , Brazil., Sales MJA; Laboratory of Research on Polymers and Nanomaterials, Institute of Chemistry , University of Brasilia , Brasília DF 70904-970 , Brazil., Paterno LG; Laboratory of Research on Polymers and Nanomaterials, Institute of Chemistry , University of Brasilia , Brasília DF 70904-970 , Brazil. |
| Abstrakt: |
The photophysical behavior and reactive oxygen species (ROS) generation by chloroaluminum phthalocyanine (AlClPc) are evaluated by steady state absorption/emission, transient emission, and electron paramagnetic resonance spectroscopies in the presence of graphene oxide (GO), reduced graphene oxide (RGO), and carboxylated nanographene oxide (NGO). AlClPc and graphene oxides form a supramolecular structure stabilized by π-π interactions, which quantitatively quenches fluorescence emission and suppresses ROS generation. These effects occur even when graphenes are previously functionalized with Pluronic F-127. A small part of quenching is due to an inner filter effect, in which graphene oxides compete with AlClPc for light absorption. Nonetheless, most of the (static) quenching arises on the formation of a nonemissive ground state complex between AlClPc and graphene oxides. The efficiency of graphene oxides on the fluorescence quenching and ROS generation suppression follows the order: GO < NGO < RGO. |
