2024/08/17 by Jonathan Rojas, Rojas, Jonathan, Zhe Wang +15
Biochemistry, Genetics and Molecular Biology · Neuroscience · Physics and Astronomy · #Biological Physics (physics.bio-ph) #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Photoreceptor and optogenetics research #Photosynthetic Processes and Mechanisms #Soft Condensed Matter (cond-mat.soft) #Spectroscopy and Quantum Chemical Studies
paper · doi:10.48550/arxiv.2408.09276
openalex publication_date 2024/08/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Photosystem I (PSI) is a photosynthetic protein which evolved to efficiently transfer electrons through the thylakoid membrane. This remarkable process attracted the attention of the biomolecular electronics community, which aims to study and understand the underlying electronic transport through these proteins by contacting ensembles of PSI with solid-state metallic contacts. This paper extends published work of immobilizing monolayers of PSI with a specific orientation, by using organophosphonate self-assembled molecules with hydrophilic heads on ultra-flat titanium nitride. Electrical measurements carried out with eutectic GaIn top contacts showed current rectification ratios of up to ~200. The previously proposed rectification mechanism, relying on the protein's internal electric dipole, was inquired by measuring shifts in the work function. Our straightforward bottom-up fabrication method may allow for further experimental studies on PSI molecules, such as embedding them in solid-state, transparent top contact schemes for optoelectronic measurements.