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

As Al 3+ 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 Al 3+ 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 Al 3+ with excellent interference resistance to typical disturbing metal ions including Cu 2+ and Fe 3+ . For the first time, concentration influence of Fe 3+ during AhzF detecting Al 3+ has been explored and it has been found that the fluorescence of AhzF-Al 3+ is partly quenched by Fe 3+ while with no influence by Cu 2+ at high concentration (above 10 −6  M), indicating its good low concentration advantage during Al 3+ detection. The binding mode exhibits a 1:1 M ratio between AhzF and Al 3+ , which are confirmed by titration test, Job’s plot, 1 H NMR spectra and mass spectrum . It also exhibits good reusability by alternate addition of Al 3+ 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 Al 3+ in tap water directly by naked eyes, which makes it possible for the application in real environment.