Detection of Lysosomal Hg2+ Using a pH-Independent Naphthalene Monoimide-Based Fluoroprobe

The development of fluorometric detection methods for toxic metal ions in real samples and inside cellular environments using fluorescent dyes has gained tremendous research interest. This work represents the design synthesis a 1,8-naphthalimide-based visible light absorbing fluorescence probe His-NMI-Bu showing an intramolecular charge transfer (ICT) feature. Photophysical properties fluoroprobe are investigated in-depth through combination steady-state, time-resolved spectroscopic techniques, DFT calculation. displays outstanding pH tolerance range 5–10 as evident from UV–Vis. measurements. exhibits chelation with Hg2+-induced attenuation via PET solution, thus acting suitable sensor mercury LOD 0.52 µM. high sensitivity selectivity towards Hg2+ validated titration various ions. Banking on its intriguing solid-state emissive properties, dye-loaded filter paper-based sensing is also developed demonstrating micromolar range. Finally, fluorophore depicts selective localization lysosomal compartment live cells which assists further to monitor presence lysosome similar depletion.