Synthesis and spectral analysis of fluorescent probes for Ce4+ and OCl− ions based on fluorescein Schiff base with amino or hydrazine structure: Application in actual water samples and biological imaging

Two Schiff base fluorescein probes (FDA, FDH) based on fluorescein-aldehyde and nitroaniline derivatives were synthesized. The effects of amino and hydrazine substituents in fluorescein backbones were examined via fluorescence and absorbance spectra. In the presence of Ce 4+ , the fluorescence of FDA was quenched due to the ligand to metal charge transfer (LMCT). Hypochloric acid can react with the C N bond, and blocking the photo induced electron transfer (PET) of FDH leads to enhancement of the fluorescence. FDA showed detection limits for Ce 4+ and OCl − as low as 63 nM in concentration range of 0–4 μM. FDH showed detection limits for OCl − as low as 0.8 μM in concentration rang 0–100 μM. Polyvinylidene fluoride (PVDF) membrane containing the probes was prepared for the real-time qualitative detection of Ce 4+ and OCl − in real water samples. The probes were successfully applied to biological imaging in vascular smooth muscle cells (VSMCs) and are expected to find applications in biosensing.