A selective fluorescent probe for relay detection of Zn2+ and tartrate: Application to logic circuit and living cell imaging.

A novel fluorescent probe 2-(2'-hydroxyphenyl)-4-(phenylethylamino)methyloxazole (HPO) has been synthesized, which performed highly selective and sensitive detection of Zn2+ ion with a discriminating enhancement over the other metal ions. The binding constant was calculated as 3.07 × 103 M-1 with detection limit of 1.22 × 10-6 M in aqueous solution (CH3CN-Tris v/v, 1/1, Tris, 10 mM, pH = 7.4). Moreover, the HPO-Zn2+ complex could serve as an excellent tartrate anion (TA). The detection mode maybe due to TA detach Zn2+ ion from HPO-Zn2+ complex leading to resulting in the release of the free probe HPO. As a result, a logic circuit has also been constructed on the basis of Zn2+ and TA as chemical inputs. Furthermore, fluorescence imaging experiments showed that probe HPO could be used as an effective fluorescent probe for detecting Zn2+ and TA in living cells.