A "Turn-On" fluorescent probe for detection and removal of Zn2+ in aqueous and its application in living cells.

[Display omitted] • 1. A compound L with an acylhydrazones structure was synthesized which can be used for detection and removal of Zn2+ in aqueous solution. • 2. The probe L can specifically recognize Zn2+ in aqeous solution, with a color change from light green to bright yellow, visible to the naked eyes. • 3. The adsorbent material SAL prepared by doping L into sodium alginate (SA) gel can efficiently remove Zn2+ from water, with color change from yellow to bright green clearly observed under UV light. • 4. The probe L exhibited no obvious cytotoxicity against not only tumor cells (A549), but two types of human normal cells (H9C2 and 3 T3) even at high concentration (50 μM). • 5. The probe L can be used as a fluorescent probe for Zn2+ in vitro. Using 3-hydroxy-2-naphthoic acid hydrazine and 4-(diethylamino) salicylaldehyde. as raw materials, compound L with an acylhydrazones structure was synthesized. The structure of compound L was characterized by nuclear magnetic resonance spectroscopy, X-ray single crystal diffraction, Fourier transform infrared spectroscopy, and mass spectrometry. The results show that Compound L can quickly and selectively recognize zinc ions in the H 2 O/DMSO (V:V = 3:7) solvent system. After that, the spectral performance of probe L was studied by fluorescence spectroscopy and UV–vis spectroscopy. The results show that the combination with Zn2+ can significantly enhance the fluorescence intensity of probe L while being almost unaffected by other coexisting ions. After that, Job's curve method, nuclear magnetic titration analysis, and mass spectrometry were used to study the binding mechanism of probe L and Zn2+. The results showed that probe L coordinated with Zn2+ is 1:1. The linear equations of different concentrations of Zn2+ and fluorescence intensity were obtained by fitting, and the detection limit of probe L for Zn2+ was determined to be 6.75 × 10-9 mol/L. The experimental study of standard addition and recovery showed that probe L could be used for the quantitative detection of Zn2+ in natural water samples. After that, we prepared L-doped sodium alginate hydrogel (SAL). The research results show that SAL has obvious adsorption capacity for Zn2+ in solution, and the color change before and after adsorption can be easily distinguished by the naked eye under ultraviolet light. SEM-EDS study showed that the microscopic morphology and composition of SAL changed significantly before and after adsorption. This fluorescent probe can be used for detection and removal of Zn2+ in aqueous solution. Also, probe L is effective for sensing for zinc (II) in living tumor cells. Overall, this work allows us to obtain a great potential to be applied to detect and remove Zn2+. [ABSTRACT FROM AUTHOR]