A novel quinoline derivative as dual chemosensor for selective sensing of Al3+ by fluorescent and Fe2+ by colorimetric methods

A simple and novel quinoline derivative (QN), based on quinoline-8-carboxaldehyde and 3-hydroxy-2-naphthoic hydrazide was synthesized. The structure of chemosensor QN was confirmed by X-ray Crystallography. The chemosensor QN as dual chemosensor showed selective fluorescence recognition of Al3+ and colorimetric detection of Fe2+. In the presence of Al3+, the sensor QN generated a noticeable fluorescence enhancement accompanied with obvious color change from colorless to yellowish green. Moreover, QN was successfully used for colorimetric sensing for Fe2+, while the solution color changed from pale yellow to dark green. The detection limit was obtained to be 1.22 x 10(-8) mol L-1 for Al3+ and 1.04 x 10(-7) mol L-1 for Fe2+. The sensing mechanism of sensor QN toward Al3+ and Fe2+ were investigated by H-1 NMR, ESI-MS and IR. Moreover, the coordination modes of QN-Al3+ and QN-Fe2+ were confirmed by theoretical calculations. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

A novel quinoline derivative QN was synthesized for selective fluorescence recognition of Al3+ and colorimetric detection of Fe2+. The sensor showed noticeable fluorescence enhancement and color change in the presence of Al3+ and successfully detected Fe2+ through colorimetric sensing.