Quantum Photothermal Self-Monitoring Fiber Probes for In Vivo Photothermal Therapy.

Area of Science:

• Quantum sensing
• Biomedical engineering
• Materials science

Background:

• Diamond nitrogen-vacancy (NV) centers offer photothermal properties for simultaneous fluorescence and heating.
• Conventional systems have low photothermal efficiency (<4°C/mW) and bulky microwave integration.

Purpose of the Study:

• To develop a miniaturized quantum photothermal fiber probe with enhanced efficiency and microwave integration.
• To create a biocompatible quantum sensor with real-time temperature feedback for in vivo applications.

Main Methods:

• Fabrication of a novel composite optoelectronic fiber guiding light and GHz microwaves.
• Integration of a micron-scale diamond at the fiber tip for photothermal conversion.
• Utilizing temperature-dependent zero-field splitting for self-monitoring with 0.2°C resolution.

Main Results:

• Achieved enhanced photothermal conversion (13°C/mW) in the 25°C-120°C range.
• Demonstrated real-time, micrometer-scale temperature self-monitoring.
• Successfully promoted in vivo spinal cord injury repair via controlled thermal stimulation.

Conclusions:

• The developed fiber probe is a new class of mass-producible, biocompatible quantum sensors.
• The platform offers high thermal efficiency and precise temperature feedback for therapeutic applications.
• This technology enables advanced in vivo interventions through controlled localized heating.