title: Steady State and Time Resolved Fluorescence Studies of Azadioxatriangulenium (ADOTA) Fluorophore in Silica and PVA Thin Films.
abstract: A cationic azadioxatriangulenium (ADOTA) dye was entrapped in silica thin films obtained by the sol-gel process and in poly (vinyl) alcohol (PVA) thin films. Azadioxatriangulenium is a red emitting fluorophore with a long fluorescence lifetime of ~20 ns. The fluorescent properties of azadioxatriangulenium in silica thin films and PVA films were studied by means of steady-state and time resolved fluorescence techniques. We have found that the azadioxatriangulenium entrapped in silica thin film has a wider fluorescence lifetime distribution (Lorentzian distribution), lower fluorescence efficiencies, shorter lifetimes compared to Azadioxatriangulenium in a PVA film. The local environment of azadioxatriangulenium molecules in the silica thin film is rich with water and ethanol, which creates the possibility of forming excited state aggregates due to high concentration of dye within a small confined area. In contrast to the PVA matrices, the porous silica films allow restricted rotations of Azadioxatriangulenium molecules, which result in faster and complex fluorescence anisotropy decays suggesting energy migration among dye molecules.
authors.affiliation: Department of Cell Biology and Immunology, Center for Fluorescence Technologies and Nanomedicine, University of North Texas Health Science Center, Fort Worth, TX 76107,USA.
authors.forename: Rahul
authors.initials: R
authors.lastname: Chib
authors.affiliation: Department of Cell Biology and Immunology, Center for Fluorescence Technologies and Nanomedicine, University of North Texas Health Science Center, Fort Worth, TX 76107,USA. ; Department of Physics and Astronomy, Texas Christian University, Fort Worth, TX, 76129, USA.
authors.forename: Sangram
authors.initials: S
authors.lastname: Raut
authors.affiliation: Department of Cell Biology and Immunology, Center for Fluorescence Technologies and Nanomedicine, University of North Texas Health Science Center, Fort Worth, TX 76107,USA.
authors.forename: Sunil
authors.initials: S
authors.lastname: Shah
authors.affiliation: Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-952 Gdańsk, Poland.
authors.forename: Beata
authors.initials: B
authors.lastname: Grobelna
authors.affiliation: Department of Cell Biology and Immunology, Center for Fluorescence Technologies and Nanomedicine, University of North Texas Health Science Center, Fort Worth, TX 76107,USA.
authors.forename: Irina
authors.initials: I
authors.lastname: Akopova
authors.affiliation: Department of Cell Biology and Immunology, Center for Fluorescence Technologies and Nanomedicine, University of North Texas Health Science Center, Fort Worth, TX 76107,USA.
authors.forename: Ryan
authors.initials: R
authors.lastname: Rich
authors.affiliation: Nano-Science Center and Department of Chemistry University of Copenhagen, Universitetsparken 5, DK2100 København Ø, Denmark.
authors.forename: Thomas Just
authors.initials: TJ
authors.lastname: Sørensen
authors.affiliation: Nano-Science Center and Department of Chemistry University of Copenhagen, Universitetsparken 5, DK2100 København Ø, Denmark.
authors.forename: Bo W
authors.initials: BW
authors.lastname: Laursen
authors.affiliation: Department of Physics and Biophysics, University of Warmia and Mazury in Olsztyn, 10-719, Poland.
authors.forename: Hanna
authors.initials: H
authors.lastname: Grajek
authors.affiliation: Department of Cell Biology and Immunology, Center for Fluorescence Technologies and Nanomedicine, University of North Texas Health Science Center, Fort Worth, TX 76107,USA. ; Department of Physics and Astronomy, Texas Christian University, Fort Worth, TX, 76129, USA.
authors.forename: Zygmunt
authors.initials: Z
authors.lastname: Gryczynski
authors.affiliation: Department of Cell Biology and Immunology, Center for Fluorescence Technologies and Nanomedicine, University of North Texas Health Science Center, Fort Worth, TX 76107,USA.
authors.forename: Ignacy
authors.initials: I
authors.lastname: Gryczynski
keywords: Azadioxatriangulenium; Fluorophore; Lorentzian lifetime distribution; Luminescence; Sol-gel process