Mechanisms of photochemistry and reactive oxygen production by fullerene suspensions in water.

Published

Journal Article

Buckminsterfullerene (C60) is a known photosensitizer that produces reactive oxygen species (ROS) in the presence of light; however, its properties in aqueous environments are still not well understood or modeled. In this study, production of both singlet oxygen and superoxide by UV photosensitization of colloidal aggregates of C60 in water was measured by two distinct methods: electron paramagnetic resonance (EPR) with a spin trapping compound, and spectrophotometric detection of the reduced form of the tetrazolium compound XTT. Both singlet oxygen and superoxide were generated by fullerol suspensions while neither was detected in the aqu/nC60 suspensions. A mechanistic framework for photosensitization that takes into account differences in C60 aggregate structure in water is proposed to explain these results. While theory developed for single molecules suggests that alterations to the C60 cage should reduce the quantum yield for the triplet state and associated ROS production, the failure to detect ROS production by aqu/nC60 is explained in part by a more dense aggregate structure compared with the hydroxylated C60.

Full Text

Duke Authors

Cited Authors

  • Hotze, EM; Labille, J; Alvarez, P; Wiesner, MR

Published Date

  • June 2008

Published In

Volume / Issue

  • 42 / 11

Start / End Page

  • 4175 - 4180

PubMed ID

  • 18589984

Pubmed Central ID

  • 18589984

Electronic International Standard Serial Number (EISSN)

  • 1520-5851

International Standard Serial Number (ISSN)

  • 0013-936X

Digital Object Identifier (DOI)

  • 10.1021/es702172w

Language

  • eng