A ratiometric fluorescent probe for Zn2+ based on pyrene-appended naphthalimide-dipicolylamine

A pyrene-appended naphthalimide-dipicolylamine was developed as a ratiometric fluorescent probe for Zn2+ ions. This probe displayed a ratiometric change in the fluorescent intensities at 385 and 530 nm corresponding to the emissions of pyrene and naphthalimide units for Zn2+ over other metal ions, allowing for a precise quantitative analysis of the Zn2+ ion. The fluorescent color change was also visualized from blue to green. We demonstrated that probe recognized Zn2+ ions based on a 1:1 stoichiometric binding event and it showed a high sensitivity (limit of detection: 10.5 nM) and a rapid detection time for the Zn2+ ion. In addition, the ratiometric change was found to be highly selective for the Zn2+ ions even in the existence of other competitive metal ions including Cd2+, Pb2+, Hg2+, Ni2+, Co2+ and Cu2+ ions. Moreover, this probe was able to detect Zn2+ ion in a wide pH range of 4-11 and it could be efficiently recycled by treating ethylenediaminetetraacetic acid (EDTA). Furthermore, this probe was successfully utilized for measurement of Zn2+ concentration contained in drug commercially available zinc supplement. (c) 2017 Elsevier B.V. All rights reserved.