Photo-controlled Zn(2+) release system with dual binding-sites and turn-on fluorescence

A phototriggered Zn-release system with dual binding-sites and turn-on fluorescence has been developed by employing a molecule with two Schiff base units as a ligand. It is found that the ligand with two Schiff base units can bind with two Zn(2+), and the bound Zn(2+) can be released completely when the Schiff base is converted into bi-benzoxazole when phototriggered. During the conversion of the Schiff base into benzoxazole, the turn-on fluorescence was detected, which provides a convenient method to monitor the process of phototrigger release. Besides, it is also found that the amount of released Zn(2+) depends on the exposure or irradiation time, which enables the possibility to manipulate the amount of Zn(2+)-release via controlling irradiation time.