9-Cyano-10-telluriumpyronin Derivatives as Red-light-activatable Raman Probes

Area of Science:

• Chemical Biology
• Spectroscopy
• Materials Science

Background:

• Photoactivatable fluorescence probes offer high spatiotemporal resolution but have limited simultaneous wavelength windows due to broad peaks.
• Raman signals possess narrower peak widths, allowing for greater simultaneous discrimination of multiple targets.

Purpose of the Study:

• To develop novel photoactivatable Raman probes for enhanced biological investigations.
• To overcome the limitations of fluorescence probes by utilizing the spectral advantages of Raman scattering.

Main Methods:

• Synthesis of 9-cyano-10-telluriumpyronin (9CN-TeP) derivatives as photoactivatable Raman probes.
• Photooxidation of the tellurium atom using red light irradiation to enhance stimulated Raman scattering (SRS) intensity.
• Modification of the probe structure to improve the stability of the oxidation product, leading to 9CN-diMeJTeP.

Main Results:

• The tellurium atom in 9CN-TeP derivatives undergoes photooxidation, significantly enhancing SRS intensity.
• A julolidine-like derivative, 9CN-diMeJTeP, was synthesized, yielding a stable oxidation product.
• The oxidation product exhibited strong electronic pre-resonance, causing a bathochromic shift and further increasing SRS intensity.

Conclusions:

• 9CN-TeP derivatives serve as effective photoactivatable Raman probes with enhanced SRS signals.
• The developed probes enable more comprehensive biological studies by overcoming the limitations of fluorescence probes.
• The photooxidation mechanism provides a tunable approach for developing advanced Raman imaging agents.