A spectroscopic study to assess the photogeneration of singlet oxygen by graphene oxide

[EN] The photogeneration of singlet oxygen (O-1(2) ) during short irradiation times of graphene oxide (GO) is assessed under visible light with soft irradiation conditions either directly monitoring the phosphorescence emission of O-1(2) at ca. 1275 nm, or indirectly by means of the fluorescent probe 9, 10-anthracene diyl-bis(methylene)dimalonic acid (ABDA). Results obtained using both methodologies lead to the conclusion that O-1(2) generation is negligible under our experimental conditions. In the case of using ABDA very small emission changes were recorded, which could be attributed to other side reactions. Special care should be taken when using this spectroscopic probe to assess the generation of O-1(2), since ABDA and related probes based on the reactivity of the anthracene fluorophore can also detect electron transfer processes. This kind of approaches have been less explored in the field of Materials Science at the nanoscale, and we believe that the knowledge on the lack of generation of O-1(2) by irradiated GO is informative and useful, especially for the assessment of the environmental and biological toxicity of nanomaterials based on GO. (C) 2019 Elsevier B.V. All rights reserved.Ministerio de Economia y Competitividad of Spain (grant CTQ2015-71004-R) and Universitat Jaume I (grant P1.1B2015-76) are thanked for their financial support. C.F-L. thanks the Ministerio de Economia y Competitividad of Spain for a FPI fellowship. Technical support from SCIC of University Jaume I is acknowledged. The Instituto de Tecnologia Quimica (ITQ) thanks the support of the Severo Ochoa Program (SEV-2016-0683), and Consejo Superior de Investigaciones Cientificas (I-Link1063). We would like to thank Dr. Francisco Bosca for his technical assistance with the singlet oxygen emission measurements at the ITQ.Felip-León, C.; Puche Panadero, M.; Miravet, JF.; Galindo, F.; Feliz Rodriguez, M. (2019). A spectroscopic study to assess the photogeneration of singlet oxygen by graphene oxide. Materials Letters. 251:45-51. https://doi.org/10.1016/j.matlet.2019.05.001S455125