Implantable Fiber Sensor for Continuous Monitoring of Light-Regulated Ascorbic Acid Dynamics.

Area of Science:

• Plant physiology
• Biomedical engineering
• Nutritional science

Background:

• Ascorbic acid (AA) levels in crops are vital for nutritional quality.
• Understanding light's dynamic regulation of AA *in vivo* is limited by destructive sampling methods.
• Current methods provide only static data, hindering real-time analysis of AA fluctuations.

Purpose of the Study:

• To develop a minimally invasive, long-term sensing method for tracking AA dynamics in living plants.
• To investigate the real-time effects of light on AA regulation *in vivo*.
• To establish a versatile sensing platform for mechanistic insights into crop nutritional improvement.

Main Methods:

• Development of an implantable fiber sensor utilizing a Co-Fe dual-atomic nanozyme (CoFe-DAzyme) and antifouling hydrogel.
• The sensor enables minimally invasive, long-term monitoring of AA in plant bleeding sap.
• Detection limit achieved was 0.081 μM, with sensor functionality maintained for up to 7 days.

Main Results:

• The developed sensor successfully tracked AA levels in lettuce *in vivo* over extended periods.
• Rapid, light-dependent fluctuations in AA concentrations were observed.
• Direct evidence was obtained on how dynamic light environments modulate this key nutritional metabolite.

Conclusions:

• The implantable fiber sensor provides a novel platform for real-time monitoring of AA in plants.
• This technology offers direct mechanistic insights into light-regulated improvements in crop nutritional quality.
• The findings are crucial for strategies aimed at enhancing plant nutritional value through controlled light environments.