A facile accessible acylhydrazone as Al3+ sensor with excellent sensitivity and selectivity

Abstract As Al3+ is detrimental both to human and other organisms, a simple sensor, acylhydrazone AhzF, is synthesized in one step and its structure is confirmed by single crystal X-ray diffraction. AhzF shows specific fluorescence turn-on response for Al3+ over other metal ions at UV 365 nm, observed by naked-eyes. Its detection limit can reach to 1.11 × 10−9 M in ethanol. Meanwhile, AhzF at low concentration can detect Al3+ with excellent interference resistance to typical disturbing metal ions including Cu2+ and Fe3+. For the first time, concentration influence of Fe3+ during AhzF detecting Al3+ has been explored and it has been found that the fluorescence of AhzF-Al3+ is partly quenched by Fe3+ while with no influence by Cu2+ at high concentration (above 10−6 M), indicating its good low concentration advantage during Al3+ detection. The binding mode exhibits a 1:1 M ratio between AhzF and Al3+, which are confirmed by titration test, Job’s plot, 1H NMR spectra and mass spectrum. It also exhibits good reusability by alternate addition of Al3+ and EDTA to the AhzF solution. The pH effect tests suggest its good sensitivity from pH 4 to pH 10 and AhzF can recognize labeled Al3+ in tap water directly by naked eyes, which makes it possible for the application in real environment.