• Effects of various salts on the spectral properties of merocyanine 540, a fluorescent probe, in aqueous media

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      https://www.ias.ac.in/article/fulltext/jcsc/110/03/0311-0317

    • Keywords

       

      Merocyanine 540; inorganic salts; absorption and fluorescence spectra; fluorescence quenching

    • Abstract

       

      The effects of several biologically-important inorganic salts (NaCl, KCl, MgCl2, MgSO4, CaCl2, EuCl3 and Er(CH3COO)3) on the electronic absorption and fluorescence spectra of merocyanine 540 (MC-540) have been determined in aqueous media. Depending on both the MC-540 concentration and the nature of salt, a new absorption band is obtained, above a threshold of salt concentration. The cations produce two types of fluorescence quenching according to their charge: in the case of monovalent ions (Na+, K+), a nonlinear Stern-Volmer behaviour is observed, while for divalent alkaline-earth (Mg2+, Ca2+) and trivalent lanthanide (Eu3+, Er3+) ions, linear Stern-Volmer relationships are established. Our results, which exclude the presence of protonated MC-540, demonstrate the existence of interactions between the inorganic ions and the MC-540 highly polar zwitterionic structure followed by an ion-induced aggregation of the dye.

    • Author Affiliations

       

      A Adenier1 F Duville1 J J Aaron1

      1. Institut de Topologie et de Dynamique des Systèmes (associé au C N R S-URA 34), Université Paris 7 Denis Diderot, 1 rue Guy de La Brosse, Paris - F-75005, France
    • Dates

       
  • Journal of Chemical Sciences | News

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