Structurally Characterized Zn 2+ Selective Ratiometric Fluorescence Probe in 100 % Water for HeLa Cell Imaging: Experimental and Computational Studies

Fluorescence recognition of Zn 2+ in 100 % aqueous medium using 2-((1, 3 dihydroxy-2-(hydroxymethyl)propan-2 ylimino) methyl) phenol (SALTM) as ratiometric probe is reported. Moreover, SALTM can discriminate Zn 2+ from Cd 2+ very effectively. The binding constant and detection limit of the probe for Zn 2+ is 2.2 × 10 4 M -1/2 and 2.79 × 10 −8 M respectively. Interestingly, corresponding naphthalene derivative (HNTM) having less water solubility fails to be a ratiometric sensor. SALTM can detect intracellular Zn 2+ in HeLa cervical cancer cells under fluorescence microscope. Moreover, DFT and TD-DFT studies support experimental findings.