Engineering Photosystem I Complexes with Metal Oxide Binding Peptides for Bioelectronic Applications

Area of Science:

• Biophysics
• Materials Science
• Renewable Energy

Background:

• Conventional dye-sensitized solar cells (DSSCs) rely on synthetic organometallic dyes.
• Photosystem I (PSI) is a natural pigment-protein complex with potential for light harvesting.
• Developing efficient bio-hybrid solar cells requires improved integration of biological components with inorganic materials.

Purpose of the Study:

• To replace synthetic dyes in DSSCs with Photosystem I (PSI).
• To engineer PSI with peptide fusions for enhanced binding to metal oxide nanoparticles.
• To investigate the binding efficiency of modified PSI complexes.

Main Methods:

• Recombinant production of ZnO binding peptide (ZOBiP)-fused PSI subunits (ZOBiP-PsaD, ZOBiP-PsaE) and TiO2 binding peptide (TOBiP)-fused ferredoxin (TOBiP-Fd) in E. coli.
• Characterization of MOBiP-fused peptides using western blotting, circular dichroism, MALDI-TOF, and cyclic voltammetry.
• Chemical cross-linking of TOBiP-Fd to PSI and incubation of modified PSI complexes with metal oxide nanoparticles.

Main Results:

• Successfully produced ZOBiP-PSI subunits and TOBiP-Fd recombinantly.
• Engineered PSI complexes (MOBiP-PSI) demonstrated significantly increased binding to metal oxide nanoparticles compared to wild-type PSI.
• Characterization confirmed the integrity and properties of the modified PSI components.

Conclusions:

• Engineered Photosystem I with specific binding peptides offers a promising strategy for creating stable bio-hybrid solar cells.
• Enhanced nanoparticle binding facilitates better integration of biological light harvesters in photovoltaic devices.
• This approach paves the way for utilizing natural pigments in next-generation solar energy technologies.