title: Two Photon Induced Luminescence of BSA Protected Gold Clusters.
abstract: In this short letter, we have synthesized the BSA protected Au25nanoclusters and studied their two photon luminescence behavior. We demonstrate that BSA Au25nanoclusters can be used as a probe with two photon excitation capability. Our results show a quadratic relation between excitation power and emission intensity whereas with one photon excitation shows a linear dependence. The emission spectrum of BSA Au25nanoclusters with one photon and two photon excitation shows no appreciable change. Due to its long wavelength emission (650 nm) and two photon excitation, BSA Au25can be potentially used as a probe for deep tissue imaging.
authors.affiliation: Center for Commercialization of Fluorescence Technologies, University of North Texas Health Science Center, 3500 Camp Bowie Blvd. Fort Worth, Texas, USA, 76107.
authors.forename: Sangram L
authors.initials: SL
authors.lastname: Raut
authors.affiliation: Department of Physics. Texas Christian University, 2800 S. University Dr., Fort Worth, Texas, USA, 76129.
authors.forename: Dmytro
authors.initials: D
authors.lastname: Shumilov
authors.affiliation: Center for Commercialization of Fluorescence Technologies, University of North Texas Health Science Center, 3500 Camp Bowie Blvd. Fort Worth, Texas, USA, 76107.
authors.forename: Rahul
authors.initials: R
authors.lastname: Chib
authors.affiliation: Center for Commercialization of Fluorescence Technologies, University of North Texas Health Science Center, 3500 Camp Bowie Blvd. Fort Worth, Texas, USA, 76107.
authors.forename: Ryan
authors.initials: R
authors.lastname: Rich
authors.affiliation: Center for Commercialization of Fluorescence Technologies, University of North Texas Health Science Center, 3500 Camp Bowie Blvd. Fort Worth, Texas, USA, 76107 ; Department of Physics. Texas Christian University, 2800 S. University Dr., Fort Worth, Texas, USA, 76129.
authors.forename: Zygmunt
authors.initials: Z
authors.lastname: Gryczynski
authors.affiliation: Center for Commercialization of Fluorescence Technologies, University of North Texas Health Science Center, 3500 Camp Bowie Blvd. Fort Worth, Texas, USA, 76107 ; Department of Cell Biology and Anatomy, University of North Texas Health Science Center. 3500 Camp Bowie Blvd. Fort Worth, Texas, USA, 76107.
authors.forename: Ignacy
authors.initials: I
authors.lastname: Gryczynski
keywords: BSA; Gold clusters; Luminescence; One and two photon excitation