Light-Harvesting in Biophotonic Optofluidic Microcavities via Whispering-Gallery Modes

Area of Science:

• Biophysics
• Bioenergy
• Materials Science

Background:

• Phycobiliproteins from cyanobacteria and microalgae are natural light-harvesting proteins.
• There is a growing demand for eco-friendly and renewable energy devices.
• Efficient conversion of biological energy into electricity remains a significant challenge.

Purpose of the Study:

• To develop a novel method for enhancing biological light-harvesting using phycobiliproteins.
• To investigate the role of light-matter interactions at the biointerface of whispering-gallery modes (WGMs).
• To improve bio-photoelectricity generation from light-harvesting biomaterials.

Main Methods:

• Utilized microdroplets as carriers for phycobiliproteins, acting as active gain materials.
• Exploited whispering-gallery modes (WGMs) to enhance light-matter interactions.
• Investigated cascade energy transfer in a biomimetic system with phycobiliprotein assemblies.

Main Results:

• Achieved significantly enhanced bio-photoelectricity through strong local electric field enhancement and photon confinement.
• Observed threshold-like behavior in photocurrent enhancement and WGM-modulated fluorescence.
• Demonstrated the impact of cavity quality factor, geometry, and refractive indices on photoelectricity and optical resonance.

Conclusions:

• Optical cavities play a critical role in enhancing light-harvesting efficiency in biological systems.
• The developed WGM-based approach offers a promising pathway for efficient bio-photoelectricity generation.
• Findings provide insights into light energy coupling mechanisms within biomaterials for sustainable energy applications.