A new simple Schiff base functionalized water-soluble polymer (PEGBN) was synthesized by one-step esterification of Schiff base derivative with carboxylated polyethylene glycol. PEGBN exhibited a sensitive and selective turn-on fluorescence response toward Al3+ over other competitive metal ions in 100% aqueous solution. The detection limit of PEGBN for Al3+ was as low as 6.15 x 10(-9) M. PEGBN displayed high selectivity to Al3+ over a wide pH range from 5 to 9. The reusability of PEGBN was demonstrated successfully by multiple cycles of alternate addition of Al3+ and EDTA to PEGBN solution. Furthermore, an INHIBIT logic gate was constructed based on the fluorescence response of PEGBN with Al3+ and EDTA as two input signals.