A novel solvent-dependently bifunctional NIR absorptive and fluorescent ratiometric probe for detecting Fe3+/Cu2+ and its application in bioimaging

Abstract A novel rhodamine-cyanine based probe LS1 was designed and synthesized, which can act as a bifunctional NIR ratiometric colorimetric and fluorescent probe for detecting Fe 3+ and Cu 2+ in solvent of MeOH/H 2 O and MeCN/H 2 O respectively. As expected, it exhibited high selectivity and sensitivity for detecting Fe 3+ and Cu 2+ over other commonly coexistent metal ions in their respective systems with a broad pH span. The detection limit was measured to be 0.737 μM for Fe 3+ and 1.019 μM for Cu 2+ . Furthermore, fluorescence imaging experiments of Cu 2+ ions in living SH-SY5Y109 cells demonstrated its value of practical application in biological systems.