Localizable and photoactivatable fluorophore for spatiotemporal two-photon bioimaging

Area of Science:

• Chemical Biology
• Microscopy
• Biotechnology

Background:

• Photoactivatable probes are crucial for spatiotemporal bioimaging.
• Existing probes often suffer from poor spatial resolution due to diffusion of water-soluble fluorophores.
• Hydroxyphenylquinazolinone (HPQ) exhibits solid-state emission but not in solution.

Purpose of the Study:

• To develop a novel photoactivatable two-photon probe for high-resolution bioimaging.
• To overcome the spatial resolution limitations of current photoactivatable probes.
• To utilize the unique properties of HPQ for localized fluorescence imaging.

Main Methods:

• Design and synthesis of a photoactivatable probe (PHPQ) using HPQ as a precursor.
• Photocleavage of PHPQ to release the HPQ fluorophore.
• Evaluation of one-photon and two-photon excited fluorescence properties.
• Assessment of spatial resolution in bioimaging applications.

Main Results:

• PHPQ successfully releases a precipitating HPQ fluorophore upon photocleavage.
• The released HPQ exhibits yellow-green fluorescence under both one-photon and two-photon excitation.
• A significant fluorescence enhancement of over 200-fold (one-photon) and 150-fold (two-photon) was observed.
• The precipitating nature of HPQ ensures localized fluorescence signals, leading to high spatial resolution.

Conclusions:

• PHPQ is an effective photoactivatable probe for spatiotemporal bioimaging.
• The probe enables high spatial resolution imaging by generating localized fluorescence signals.
• PHPQ offers significant fluorescence enhancement, improving imaging sensitivity and clarity.