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DETECTION OF PORPHYRIN EXCITED STATES IN THE INTACT BOVINE LENS
Author(s) -
Roberts Joan E.,
Atherton Stephen J.,
Dillon James
Publication year - 1991
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1991.tb02102.x
Subject(s) - porphyrin , chemistry , flash photolysis , triplet state , photochemistry , excited state , lens (geology) , fluorescence , spectroscopy , ultrafast laser spectroscopy , kinetics , molecule , reaction rate constant , optics , atomic physics , physics , organic chemistry , quantum mechanics
Previous steady state and time resolved spectroscopic studies on porphyrins have shown that the triplet lifetimes of those sensitizers that bind to lens proteins are lengthened by several orders of magnitude. Presented here is an extension of this experiment to measure these transients in an intact bovine lens. As demonstrated by steady state fluorescence spectroscopy and flash photolysis, mesotetra ( p ‐sulfonatophenyl)porphyrin (TPPS) binds to lens proteins. In air‐saturated aqueous solution, TPPS has a triplet lifetime of 2 μs. In an intact bovine lens the triplet state decayed via biexponential kinetics with lifetimes of 0.16 and 1.6 μs. In addition to a lengthening of the lifetime there was a red shift in the triplet transient spectra of10–20 nm of the porphyrin in the intact lenses.