Selective and sensitive solid sensory substrates for detecting Al(III) in pure
water are reported. The material is a flexible polymer film that can be handled and exhibits gel
behavior and membrane performance. The film features a chemically anchored salicylaldehyde
benzoylhydrazone derivative as an aluminum ion fluorescence sensor. A novel procedure for
measuring Al(III) at the ppb level using a single solution drop in 20 min was developed. In this
procedure, a drop was allowed to enter the hydrophilic material for 15 min before a 5 min
drying period. The process forced the Al(III) to interact with the sensory motifs within the
membrane before measuring the fluorescence of the system. The limit of detection of Al(III)
was 22 ppm. Furthermore, a water-soluble sensory polymer containing the same sensory
motifs was developed with a limit of detection of Al(III) of 1.5 ppb, which was significantly
lower than the Environmental Protection Agency recommendations for drinking water.
