Novel fluorescent sensor for Al3+ based on a bis-tetraphenylimidazole Schiff base

Although some detection methods for Al 3+ have been presented, the rapid, simple and in-situ detection on Al 3+ with high selectivity and sensitivity was still anticipated. In this work, a “turn-on” and color-changed fluorescence sensor for Al 3+ was reported with the high selectivity and low detection limitation. A bis-tetraphenylimidazole Schiff base ( bis-TPMS ) was prepared by simple “1 + 2” condensation in 80 % yield. It displayed the strong “turn-on” purple fluorescence on sensing Al 3+ selectively among various metallic ions and anions. The detection limitation was as low as 1.56 × 10 -8 M. The sensing mechanism was deduced as Al 3+ was located in the opening cavity composed of HC = N, OH and NH groups. This sensing ability of bis-TPMS for Al 3+ was successfully used in test paper, on-site detection for real samples of gastric tablets, indicating the good application prospect in the simple, rapid and in-situ detection for Al 3+ in real samples.