A Sensitive Near-Infrared Fluorescent Sensor for Mitochondrial Hydrogen Sulfide

Area of Science:

• Biochemistry
• Cell Biology
• Chemical Biology

Background:

• Hydrogen sulfide (H₂S) acts as a crucial gasotransmitter in cellular processes.
• Mitochondria play a key role in H₂S metabolism and function, but specific detection methods are limited.
• Existing fluorescent probes for H₂S often lack mitochondrial specificity.

Purpose of the Study:

• To develop a novel, highly sensitive fluorescent probe for detecting mitochondrial hydrogen sulfide.
• To enable real-time imaging and quantification of H₂S in live mammalian cells.
• To investigate the role of H₂S in mitochondrial function and pathways.

Main Methods:

• Synthesis of a new near-infrared fluorescent probe, nimazide, incorporating a sulfonyl azide moiety.
• Utilizing a QSY-21 dark quencher core structure for probe design.
• Testing nimazide's response to H₂S in vitro and in live cells, including specificity and kinetic studies.

Main Results:

• Nimazide demonstrated rapid and specific fluorescence turn-off responses to H₂S.
• The probe successfully detected nanomolar concentrations of extracellular H₂S in live cells.
• Mitochondrial H₂S generated biologically was successfully imaged in live mammalian cells using nimazide.

Conclusions:

• Nimazide is a highly sensitive and specific fluorescent probe for detecting mitochondrial H₂S.
• This probe facilitates advanced imaging of H₂S dynamics in live cells.
• Nimazide offers a valuable tool for studying H₂S roles in mitochondrial biology and metabolism.