Biocompatible 7-nitro-2,1,3-benzoxadiazole-embedded naphthalimide for exploring endogenous H₂S in living cells

Area of Science:

• Biochemistry
• Molecular Biology
• Chemical Biology

Background:

• Hydrogen sulfide (H2S) is a vital biomolecule involved in cellular signaling and antioxidant functions.
• Dysregulated H2S levels are implicated in various pathologies, including cancer, necessitating precise detection methods.
• Existing methods for H2S detection in biological systems often lack selectivity and sensitivity.

Purpose of the Study:

• To develop a biocompatible and activatable fluorescent molecular probe for sensitive and selective detection of H2S in living cells.
• To enable real-time monitoring of endogenous H2S generation.
• To investigate the role of H2S as an antioxidant defense mechanism in oxidatively stressed cells.

Main Methods:

• Synthesis and characterization of a novel naphthalimide-based fluorescent probe (probe 1) incorporating a 7-nitro-2,1,3-benzoxadiazole moiety.
• Evaluation of probe 1's response to H2S, including fluorescence emission wavelength (530 nm) and specificity.
• Assessment of probe 1's biocompatibility, cell permeability, and performance in live HeLa cells under oxidative stress conditions.

Main Results:

• The developed probe 1 specifically detects H2S, producing a distinct fluorescence signal at 530 nm.
• Probe 1 demonstrated high biocompatibility and excellent cell permeability in HeLa cells.
• The probe successfully monitored endogenous H2S fluctuations, correlating with antioxidant defense responses in oxidatively stressed cells.

Conclusions:

• The novel fluorescent probe provides a powerful tool for sensitive and selective detection of H2S in living biological systems.
• This probe facilitates real-time imaging of H2S dynamics, offering insights into its physiological and pathological roles.
• The findings highlight the potential of this probe for advancing research in H2S-related diseases and cellular defense mechanisms.