Formación fotoinducida y detección de radicales hidroxilo (•OH) empleando nanomateriales basados en puntos cuánticos de CdSe/ZnS

Abstract

Quantum dots (PCs) of CdSe / ZnS were synthesized by the hot injection method and using oleic acid as binder. The obtained PCs were characterized by UV-vis, fluorescence, FT-IR, DR-X, 1H NMR and XPS determining both their optical properties (λmax absorption = 545 nm and a λmax emission = 557 nm), with high photostability and performance fluorescence quantum ΦF = 59.7% in the green region; as structural, evidencing a core diameter of CdSe of 2.7 nm with 10% formation of the first monolayer of ZnS and a cubic crystal structure of Zinc Blende. The capacity of OH formation of the PCs was evaluated by means of the fluorescence monitoring of the degradation of the luminol, from the photoexcitation with visible light of the PCs. Although the amount of monolayer obtained was small, it should be noted that achieved a 29% degradation of luminol (k = 0.696), also the presence of • OH was verified using mannitol as a • OH scavenger achieving a notable decrease in the process of degradation of luminol (9%, k = 0.092) which evidence and enhances the capacity of • OH formation by the PCs. In contrast, the capacity of the PCs in the detection of • OH was studied through chemiluminescence reactions and in the presence of H2O2, demonstrating its potential application as emitters chemiluminescent The spontaneity of both the training processes and the detection of • OH by the PCs was corroborated by means of cyclic voltammetry, which not only demonstrates the dual capacity of the CdSe / ZnS PCs to carry out the two processes, but also It also encourages the use of its properties, as a novel alternative in environmental processes such as the degradation of pollutants, or health as possible optical sensors.