Real-time detection of singlet-oxygen signatures using a single-photon avalanche diode detector

Area of Science:

• Biomedical Engineering
• Photochemistry
• Medical Physics

Background:

• Singlet-oxygen (O₂) is a crucial cytotoxic agent in photodynamic therapy (PDT).
• Effective PDT requires precise control over singlet-oxygen production.
• Current methods may lack the speed for real-time monitoring and adjustment.

Purpose of the Study:

• To develop a highly light-sensitive system for real-time detection of singlet-oxygen luminescence.
• To enable rapid quantification of singlet-oxygen dynamics in photosensitized reactions.
• To facilitate immediate feedback for optimizing PDT treatment parameters.

Main Methods:

• Utilized a single-photon avalanche diode (SPAD) detector.
• Employed time-correlated single-photon counting (TCPSC) techniques.
• Investigated singlet-oxygen generation from organic nitrobenzoselenadiazole photosensitizers.

Main Results:

• Achieved real-time detection of singlet-oxygen luminescence signatures.
• Extracted singlet-oxygen dynamics with acquisition times as short as 1 second.
• Demonstrated the system's sensitivity for detecting photosensitized singlet-oxygen.

Conclusions:

• The developed SPAD-based system offers rapid, real-time detection of singlet-oxygen.
• Short acquisition times are feasible for monitoring singlet-oxygen production.
• This technology can potentially enhance clinical PDT by allowing real-time light dose adjustments for improved treatment outcomes.