Mercuric ion-induced signaling by a dual turn-off/on switching of a quinoline-based fluorescent sensor

Kahraman U., Güney O.

JOURNAL OF LUMINESCENCE, vol.170, pp.155-160, 2016 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 170
  • Publication Date: 2016
  • Doi Number: 10.1016/j.jlumin.2015.10.046
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.155-160
  • Istanbul Technical University Affiliated: Yes


Quinoline-based fluoroprobe, 3-isocyanatopropyl triethoxysilane grafted 3-aminoquinoline (AqI) has been designed and synthesized for detection of Hg2+ in aqueous solution. Fluorescent molecule, AqI was characterized by FTIR and NMR spectroscopy, and photophysical properties in solvents with different polarities were elucidated by UV-vis and fluorescence measurements. Quantum yield of AqI was calculated (Phi(F) = 0.15) and acid dissociation constant (pK(a) = 4.14 +/- 0.15) was determined using data of integrated emission intensity versus pH. AqI shows emission quenching followed by fluorescence turn-on upon coordination-mediated complexation of Hg2+ ions. The fluorescence turn-on emission distinguishes Hg2+ ion from interfering metal ions and AqI is found to be selective for Hg2+ ion in buffered aqueous-ethanol solution (4:1, v/v) at pH 6.0. Equilibrium constant for the formation of complex between AqI and Hg2+ ions was calculated as K = 3.08 x 10(6) M-2/3 applying by spectrofluorometric titration and stoichiometry of complex was determined as AqI(2)Hg(3)(2+) (2:3). (C) 2015 Elsevier B.V. All rights reserved.