Static Disorder has Dynamic Impact on Energy Transport in Biomimetic Light-Harvesting Complexes

Area of Science:

• Biophysics
• Photosynthesis research
• Biomimetic systems

Background:

• Photosynthetic light-harvesting complexes exhibit high energy transport efficiency.
• Synthetic control over structural and energetic factors in natural systems is limited.
• Understanding these factors is key to artificial photosynthesis and energy technologies.

Purpose of the Study:

• To create and investigate a biomimetic light-harvesting complex for studying energy transfer.
• To identify critical factors influencing long-range energy transfer efficiency.
• To establish a controllable model system for fundamental research.

Main Methods:

• Constructed a circular array of identical chromophores on a tobacco mosaic virus coat protein scaffold.
• Utilized transient absorption anisotropy measurements to confirm energy transport.
• Employed time-resolved emission spectroscopy to observe spectral dynamics.
• Performed kinetic Monte Carlo simulations to model energy transfer pathways.

Main Results:

• Confirmed energy transport via ultrafast depolarization and spectral redshifting.
• Kinetic Monte Carlo simulations accurately reproduced anisotropy decay data.
• Identified an inter-site hopping rate of up to 1.6 ps^-1.
• Disorder in orientation, site energy, and coupling are critical for long-range transfer.

Conclusions:

• The biomimetic system effectively mimics energy transfer processes.
• Static disorder is a key parameter to control for optimizing energy transport.
• This system serves as a valuable bottom-up model for light-harvesting research.