A chromone-based colorimetric fluorescence sensor for selective detection of Cu2+ions, and its application for in-situ imaging

Abstract

A chromone-based chemosensor Probe 1 was synthesized, and characterized by FTIR, UV-vis, 1H NMR, 13C NMR, and mass spectrometric studies. Probe 1 exhibited high selectivity and sensitivity for the Cu2+ions over various metal ions (Al3+, Cr3+, Co2+, Cd2+, Mn2+, Fe3+, Ni2+, Zn2+) that was investigated by colorimetric, absorption, and fluorescence titrations. The binding mode of Probe 1 with the Cu2+ ion was derived from Job's plot measurements, and it showed 2:1 stoichiometry. Probe 1 revealed an association constant value of 8.48 × 108 M−2 as determined by employing non-linear least square fit data. The detection limit of Probe 1 for the Cu2+ion was found to be 0.273 × 10−6 mol L−1. Furthermore, Probe 1 was implemented to detect Cu2+ ions in different tissues of the liver fluke, infected and non-infected bovine liver. DFT studies were performed to support the sensing mechanism. The results of these experiments demonstrate that Probe 1 could be a promising chemosensor for the instant naked eye and fluorescence detection of Cu2+ ions in different biological samples.