title: Using Pyridinium Styryl Dyes as the Standards of Time-Resolved Instrument Response.
abstract: In this paper, two pyridinium styryl dyes, [2-(4-dimethylamino-phenyl)-vinyl]-1-methylpyridinium iodide (DASPMI), were synthesized and characterized by steady state fluorescence spectroscopy as well as picosecond and femtosecond time-resolved fluorescence spectroscopies. Both dyes exhibit large Stokes shifts and fluorescence decays equivalent to the instrument response function (IRF) standards employed in time-correlated single-photon counting. Due to their styryl and pyridinium moieties, DASPMIs have higher peak fluorescence intensity and shorter excited-state lifetimes than iodide ion-quenched fluorophores. The fluorescence lifetimes of o-DASPMI and p-DASPMI were measured to be 6.6 ps and 12.4 ps, respectively. The fluorescence transients of these DASPMIs were used as the IRFs for iterative reconvolution fitting of the time-resolved fluorescence decay profiles of Rhodamine B (RhB), sulforhodamine B (SRB), and the SRB-SRB2m RNA aptamer complex. The quality of the fits employing the DASPMI-derived IRFs are consistently equivalent to those employing IRFs obtained from light scattering. These results indicate that DASPMI-derived IRFs may be suited for a broad range of applications in time-resolved spectroscopy and fluorescence lifetime imaging microscopy (FLIM), especially in the visible emission range.
authors.affiliation: State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.affiliation: State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China.
authors.forename: Mengfang
authors.initials: M
authors.lastname: Chang
authors.affiliation: State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Yi
authors.affiliation: State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China.
authors.forename: Menghui
authors.initials: M
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China.
authors.forename: Xiaodan
authors.initials: X
authors.lastname: Cao
authors.affiliation: State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China.
authors.forename: Zhongneng
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China sjzhang@phy.ecnu.edu.cn.
authors.forename: Sanjun
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Pan
authors.affiliation: JILA, National Institute of Standards and Technology (NIST), University of Colorado, Boulder, Colorado, USA.
authors.forename: Chun-Wei
authors.initials: CW
authors.lastname: Shih
authors.affiliation: JILA, National Institute of Standards and Technology (NIST), University of Colorado, Boulder, Colorado, USA.
authors.forename: Ralph
authors.initials: R
authors.lastname: Jimenez
authors.affiliation: State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Xu
keywords: Fluorescence quenching; instrument response function (IRF); pyridinium styryl dyes; time-resolved fluorescence