title: Rational design principle for modulating fluorescence properties of fluorescein-based probes by photoinduced electron transfer.
abstract: Fluorescence properties of fluorescein-based probes are shown to be finely controlled by the rate of photoinduced electron transfer from the benzoic acid moiety (electron donor) to the singlet excited state of the xanthene moiety (electron acceptor fluorophore). The occurrence of photoinduced electron transfer is clearly evidenced by transient absorption spectra showing bands due to the radical cation of the electron donor moiety and the radical anion of the xanthene moiety, observed in laser flash photolysis experiments. The photoinduced electron transfer rates and the rates of back electron transfer follow the Marcus parabolic dependence of electron transfer rate on the driving force. Such a dependence provides for the first time a quantitative basis for a rational design principle which has high efficiency in modulating fluorescence properties of fluorescein-based probes.
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Miura
authors.forename: Yasuteru
authors.initials: Y
authors.lastname: Urano
authors.forename: Kumi
authors.initials: K
authors.lastname: Tanaka
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Nagano
authors.forename: Kei
authors.initials: K
authors.lastname: Ohkubo
authors.forename: Shunichi
authors.initials: S
authors.lastname: Fukuzumi