title: Photosensitized Singlet Oxygen Production upon Two-Photon Excitation of Single-Walled Carbon Nanotubes and Their Functionalized Analogs.
abstract: Single-walled carbon nanotubes (SWNTs) functionalized with -COOH (along with some sulphonation and nitration), and/or modified with chitosan were prepared and tested for their singlet oxygen ((1)O(2)) production. The emission from (1)O(2) observed upon SWNT irradiation at 532 nm was due to a two-photon process, while (1)O(2) production via excitation at 355 nm occurred through a conventional one-photon pathway. The relative quantum yield of (1)O(2) production at excitation wavelength of 532 nm was found to be 0.00, 0.07-0.13 and 0.24-0.54 for highly-functionalized, partially-functionalized and non-functionalized SWNT samples respectively. The nanotube-mediated generation of (1)O(2) may find applications in both targeted destruction of tumor cells and selective degradation of drug molecules. Our research provides a practical approach to modulate the production of reactive oxygen species from SWNTs via surface functionalization/modification.
authors.affiliation: Department of Chemistry, Jackson State University, Jackson, Mississippi 39211.
authors.forename: Naveen
authors.initials: N
authors.lastname: Gandra
authors.forename: Pui Lam
authors.initials: PL
authors.lastname: Chiu
authors.forename: Wenbing
authors.initials: W
authors.lastname: Li
authors.forename: Yolanda R
authors.initials: YR
authors.lastname: Anderson
authors.forename: Somenath
authors.initials: S
authors.lastname: Mitra
authors.forename: Huixin
authors.initials: H
authors.lastname: He
authors.forename: Ruomei
authors.initials: R
authors.lastname: Gao