Design and synthesis of a new selective fluorescent chemical sensor for Cu2+ based on a Pyrrole moiety and a Fluorescein conjugate

Abstract

A new fluorescein derivative, namely, (E)-2-(((1H-pyrrol-2-yl) methylene)amino)-3′,6′-dihydroxyspiro[isoindoline-1,9′-xanthen]-3-one (FLPY), was designed, synthesized, and structurally characterized to develop a chemosensor. The interactions of FLPY with different metal ions have been studied over UV–vis absorption spectra and fluorescent spectra. The results show that FLPY exhibits high sensitivity and selectivity toward Cu2+ among many other metal cations in a DMSO/HEPES (3:1, v/v, 1mM, pH 7.2) solution. The binding association constant (Ka) of FLPY for Cu2+ based on a 1:1 stoichiometry was estimated to be 1.29×104M−1 in the solution. The detection limit of Cu2+ by FLPY was further determined to be 0.296μM.