A Fluorescent Sensor for Al(III) and Colorimetric Sensor for Fe(III) and Fe(II) Based on a Novel 8-Hydroxyquinoline Derivative

A novel 8-hydroxyquinoline-based fluorescent and colorimetric chemosensor was designed, synthesized and fully characterized. The sensor showed high selectivity and sensitivity toward Al3+ over other tested cations in EtOH/H2O (1:99, v/v) medium. The increase in fluorescence intensity was linearly proportional to the concentration of Al3+ with a detection limit of 7.38 x 10(-6) M. Moreover, the sensor exhibited an obvious color change from yellow to black in the presence of Fe2+ and Fe3+ in EtOH/THF (99:1, v/v) solution. The absorbance changes showed a linear response to iron ions with the detection limits of 4.24 x 10(-7) M and 5.60 x 10(-7) M for Fe2+ and Fe3+, respectively. Thus, this chemosensor provides a novel approach for selectively recognition of Al3+, Fe3+ and Fe2+ among environmentally relevant metal ions.