Novel Schiff Base Synthesis of E-N-(1-(1H-phenothiazin-2yl)-ethylidene)-3-((E)-(2-phenylhydrazono) Methyl) Aniline “Turn-On” Fluorescent Chemosensor for Sensitivity and Selectivity of Detection of Cr3+ and Pb2+ Ions

The Synthesized E N (1-(1H phenothiazin-2yl)-ethylidene)-3-((E)-(2-phenylhydrazono)methyl)aniline (AT) was characterized by FT-IR, MS, H-1, and C-13 spectroscopy instruments. The chemosensor demonstrates fluorescent performance with high sensitivity and selectivity detection of CP3+ and Pb2+ over other coexistent metal ions in 100% aqueous solution, and even with a visual fluorescence change from light yellow to light blue. The probe shows "turn-on" fluorescence intensity at 428 nm (excitation wavelength 290) in HEPES buffer solution in EtOH: H2O (1:4, v/v, pH = 7.0). Significantly, the fluorescence enhancement was attributed to photoinduced electron transfer (PET). The Job plot for showed CP3+ and Pb2+ complex formation for both metal ions with 1:1 stoichiometry and was predicted at 0.6 mu M concentration. Additionally the binding constant was found to be 2.13 x 10(4) M (1)(R-2 = 0.9991) and 2.37 x 10(4) M (1)(R-2 = 0.9996) according to Benesi-Hildebrand equation and detection limit at 8.63 x 10 (7) M (R-2 = 0.9992) and 7.42 x 10 (7) M (R-2 = 0.9990) and WHO (World Health Organization) allowed (7.4 mu M) for drinking water. The pH experiments range from 4 to 10 in sensing application and reversible and irreversible due to EDTA + Cr-3(+) and EDTA + Pb2+ added into AT solution. The theoretical calculation was performed by B3LYP/6-31*G in Gaussian 09 program. The CYGD has strong cytotoxic in-vitro activity against cell line HepG2. We believe that our protocol receptor would be a valuable addition in academia for its optical properties and also excellent practical applications in biomedical industries. (C) 2020 Elsevier Ltd. All rights reserved.