NitroxylFluor: A Thiol-Based Fluorescent Probe for Live-Cell Imaging of Nitroxyl

Area of Science:

• Chemical Biology
• Biomedical Engineering
• Organic Chemistry

Background:

• Nitroxyl (HNO) is a crucial reactive nitrogen species, but its detection is challenging due to rapid reactions with biological thiols.
• Existing methods struggle with selectivity and sensitivity in biological settings, especially in the presence of high thiol concentrations.

Purpose of the Study:

• To develop a novel, highly selective, and sensitive fluorescent probe for detecting nitroxyl (HNO) in biological systems.
• To overcome the challenge of HNO's high reactivity with biological thiols.

Main Methods:

• Designed a thiol-based HNO-responsive trigger incorporating the alpha-effect and Thorpe-Ingold effect for rapid cyclization.
• Synthesized NitroxylFluor, a fluorescent probe utilizing this trigger mechanism.
• Evaluated probe performance using HNO donors, assessing selectivity against various reactive species and efficacy in thiol-rich environments.

Main Results:

• NitroxylFluor exhibits a significant 16-fold fluorescence turn-on in response to HNO.
• The probe demonstrates excellent selectivity over reactive nitrogen, oxygen, and sulfur species.
• Effective HNO detection was achieved in the presence of mM concentrations of glutathione.
• Successful live cell imaging of HNO was performed using NitroxylFluor.

Conclusions:

• NitroxylFluor is a robust and selective fluorescent probe for detecting nitroxyl (HNO).
• The probe's design overcomes the challenge of biological thiol interference, enabling sensitive HNO detection.
• NitroxylFluor is suitable for live cell imaging, advancing the study of HNO in biological systems.