Oxalohydrazide‐Based Chemosensor for Detection of Cu2+/Fe3+ Ions and Its Application in Live Cell Imaging

Abstract

AbstractThe N1,N2‐diphenyloxalohydrazide OX(HA)2 chemosensor was synthesized and used as a colorimetric and fluorescent receptor to detect Cu2+ and Fe3+ ions in the presence of other metal ions. A range of physicochemical approaches were utilized to characterize the symmetrical oxalohydrazide‐based receptor, including FT‐IR, 1H and 13C NMR, TGA, and mass spectrometry. According to single crystal X‐ray diffraction investigation, OX(HA)2 crystallizes in monoclinic with space group C2/c. UV‐Vis and fluorescence spectroscopy were used to thoroughly explore OX(HA)2’s sensing capabilities towards diverse cations. Using measurements of fluorescence intensity, the binding constant for OX(HA)2 with Cu2+/Fe3+ ions was calculated to be 2.78×103 M−1 and 1.12×103 M−1 with the lower detection limit of 0.43 μM and 0.2 μM respectively. With a 1 : 1 binding mechanism validated by Job's plot, mass spectral analysis, FT‐IR spectra, and density functional theory, the dual‐sensing receptor exhibits remarkable selectivity and sensitivity towards Cu2+ and Fe3+ ions. The average fluorescence lifetimes of OX(HA)2, OX(HA)2+Cu2+, and OX(HA)2+Fe3+ were calculated to be 2.19 ns, 1.73 ns, and 1.26 ns, respectively. This fluorescence lifetime measurement results strongly support the complexation of Cu2+ and Fe3+. When Cu2+ and Fe3+ ions bind with OX(HA)2, they induce the ‘Turn‐Off’ signal. Then, fluorescence imaging of the OX(HA)2 receptor in MDA‐MB‐231 demonstrated that the receptor holds a lot of promise for usage in bioimaging and their IC50 value for cytotoxicity is 96.96 μg. Furthermore, fluorescence microscopy experiments demonstrate that OX(HA)2 can be utilized as a fluorescent probe for detecting Cu2+ and Fe3+ ions in living cells, making it potentially helpful as an anticancer medication.