Pyrene-based ratiometric and fluorescent sensor for selective Al3+ detection

A pyrene-based sensor, named DBT, was synthesized through a one-step reaction and used as a ratiometric and fluorescent sensor for recognizing Al3+ . The sensor showed high selectivity and sensitivity toward Al(3+ )relative to other competitive metal ions. DBT exhibited very weak fluorescence because of the photo-induced electron transfer process (PET). In the presence of Al3+ the emission of DBT at 451 nm enhanced owing to the coordination between DBT and Al3+ which hindered the PET. The detection of Al3+ by DBT was realized in a wide pH range of 5-12. The detection limits of Al3+ were 0.19 and 0.10 mu M by ratiometric absorption (A(360nm) /A(342nm)) and fluorescent (F-451nm) methods, respectively. Moreover, DBT was also successfully applied to detect Al3+ in practical water samples and solid phase (TLC plate).