A Simple and Rapid “Turn-On” Fluorescent Probe Based on Binuclear Schiff Base for Zn<sup>2+</sup> and Its Application in Cell Imaging and Test Strips
A series of colorful binuclear Schiff bases derived from the different diamine bridges including 1,2- ethylenediamine (bis-Et-SA, bis-Et-4-NEt<sub>2</sub>, bis-Et-5-NO<sub>2</sub>, bis-Et-Naph), 1,2-phenylenediamine (bis-Ph-SA, bis-Ph-4-NEt<sub>2</sub>, bis-Ph-5-N...
Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2024-12-01
|
| Series: | Molecules |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1420-3049/29/24/5850 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | A series of colorful binuclear Schiff bases derived from the different diamine bridges including 1,2- ethylenediamine (bis-Et-SA, bis-Et-4-NEt<sub>2</sub>, bis-Et-5-NO<sub>2</sub>, bis-Et-Naph), 1,2-phenylenediamine (bis-Ph-SA, bis-Ph-4-NEt<sub>2</sub>, bis-Ph-5-NO<sub>2</sub>, bis-Ph-Naph), dicyano-1,2-ethenediamine (bis-CN-SA, bis-CN-4-NEt<sub>2</sub>, bis-CN-5-NO<sub>2</sub>, bis-CN-Naph) have been designed and prepared. The optical properties of these binuclear Schiff base ligands were fully determined by UV–Vis absorption spectroscopy, fluorescence emission spectroscopy, and time-dependent-density functional theory (TD-DFT) calculations. The inclusion of D-A systems and/or π-extended systems in these binuclear Schiff base ligands not only enables adjustable RGB light absorption and emission spectra (300~700 nm) but also yields high fluorescence quantum efficiencies of up to 0.84 in MeCN solution. Then, with the ESIPT (excited-state intramolecular proton transfer) property, fluorescence analysis showed that the probe bis-Et-SA and bis-Ph-SA could recognize Zn<sup>2+</sup> via the “turn on” mode in the MeCN solution. During the detection process, bis-Et-SA and bis-Ph-SA demonstrate rapid response and high selectivity upon the addition of Zn<sup>2+</sup>. The coordination of Zn<sup>2+</sup> with the oxygen atom and Schiff base nitrogen atom in a tetrahedral geometry is confirmed by Job’s plot, FT-IR, and <sup>1</sup>H NMR spectroscopy. In addition, the paper test and Hela cells were successfully carried out to detect Zn<sup>2+</sup>. Moreover, the sensitivity of bis-Et-SA and bis-Ph-SA is much better than that of those Schiff base ligands containing only one chelating unit [O^N^N^O]. |
|---|---|
| ISSN: | 1420-3049 |