A quinoline appended naphthalene derivative based AIE active 'turn-on' fluorescent probe for the selective recognition of Al3+ and colourimetric sensor for Cu2+: Experimental and computational studies

摘要

A naphthalene quinoline based sensor L is being designed with hydrazine moeity acting as a bridge capable of displaying aggregation induced emission (AIE) properties. L can detect Cu2+ in CH3OH/aqueous HEPES buffer medium through sharp colorimetric responses. The ligand (L) shows an excellent selectivity toward Al3+ ion among the other fourteen metal ions studied. The addition of the metal Al3+ to the solution of L generates a noticeable fluorescence enhancement accompanied with obvious colour change detected by the naked eye under UV light with high binding constant of 6.22 x 10(6) M-1. The sensitivity of the fluorescent based sensor L (3.10 mu M) for Al3+ is far below the limit in the World Health Organization (WHO) guidelines for drinking water (7.41 mu M). The binding of the ligand L with Al3+ was investigated through ESI-Mass and Job's plot analysis. The Density Functional Theory and TDDFT calculations were performed in order to demonstrate the structure of ligand and complexes and its electronic properties. Moreover the ligand response towards Al3+ ion remains convincing through the solid phase study carried out by mortar pestle. Therefore, sensor L could be useful for detection of Al3+ as a laboratory indicator in real sample. (C) 2016 Published by Elsevier B.V.