Development of a synthetic strategy for Water soluble tripodal receptors: Two novel fluorescent receptors for highly selective and sensitive detections of Fe3+ and Cu2+ ions and biological evaluation

A general synthetic strategy is developed to synthesize water soluble receptors by employing tripodal system based on a cyclotriphosphaze platform. The developed model is successfully synthesized and characterized by using elemental analysis, FT-IR, MALDI-TOF, H-1 NMR, C-13 NMR and P-31 NMR techniques. The fluorescence sensing performance of prepared water soluble tripodal systems were evaluated by UV/Vis and fluorescence spectroscopies. According to obtained results, two novel water-soluble sensing platforms were selective and sensitive fluorescence receptors for detections of Fe3+ and Cu2+ ions in both the absence and presence of competitive ions. In addition, the iron receptor also displays biological function, therefore, the cytotoxicity and fluorescence microscopy experiments were applied and it was demonstrated that compound 3 was non-cytotoxic, and can be used as fluorescence imaging sensors for Fe3+ in living cells. According to obtained results, proposed synthetic strategy could be applied to develop water soluble receptors for not only iron and/or copper ions but also many different metal ions of interest using a variety of fluoroionophores.