title: Two-photon excitation studies of m-THPC photosensitizer and photodynamic activity in an epithelial cell line.
abstract: A femtosecond laser delivering pulses of wavelength 800nm and 124fs duration at rates of 1kHz has been used to investigate the two-photon excited fluorescence in the photosensitizer m-THPC. The scaling of fluorescence amplitude with laser power and fluorescence sidelight imaging are found to support a predominantly two-photon excitation mechanism. A value for the two-photon cross-section of δ=1.8×10(-57)m(4)s is derived by comparing the fluorescence signals excited by wavelengths of 800 and 400nm. Preliminary results demonstrating the two-photon induced PDT activity of m-THPC in an epithelial cell line are also reported.
authors.affiliation: Department of Physics, University of Hull, Hull HU6 7RX, UK; Department of Physics and Applied Mathematics, Pakistan Institute of Engineering and Applied Sciences, Islamabad, Pakistan.
authors.forename: M
authors.initials: M
authors.lastname: Atif
authors.affiliation: Department of Physics, University of Hull, Hull HU6 7RX, UK.
authors.forename: P E
authors.initials: PE
authors.lastname: Dyer
authors.affiliation: Department of Biology, University of Hull, Hull HU6 7RX, UK.
authors.forename: T A
authors.initials: TA
authors.lastname: Paget
authors.affiliation: Department of Physics, University of Hull, Hull HU6 7RX, UK.
authors.forename: H V
authors.initials: HV
authors.lastname: Snelling
authors.affiliation: Institute of Microwaves and Photonics, University of Leeds, UK.
authors.forename: M R
authors.initials: MR
authors.lastname: Stringer