Integration of Photosynthetic Protein Molecular Complexes in Solid-State Electronic Devices

Abstract

Plants and photosynthetic bacteria contain protein−molecular complexes that harvest photons with nearly optimum quantum yield and an expected power conversion efficiency exceeding 20%. In this work, we demonstrate the integration of electrically active photosynthetic protein− molecular complexes in solid-state devices, realizing photodetectors and photovoltaic cells with internal quantum efficiencies of approximately 12%. Electronic integration of devices is achieved by self-assembling an oriented monolayer of photosynthetic complexes, stabilizing them with surfactant peptides, and then coating them with a protective organic semiconductor.

Designer short peptide surfactants stabilize G protein-coupled receptor bovine rhodopsin

“…We have found that this class of designed peptide surfactants can stabilize not only the function of GPCR bovine rhodopsin in solution but also multiple subunits of the photosystem I (PSI) protein complex (35) on a dry surface (36,37). These peptide surfactants represent a promising approach to membrane protein crystallization.…”

“…We used green plant PSI (35) to demonstrate that these designer short peptide surfactants can stabilize membrane proteins (36,37). PSI is a chlorophyll-containing membrane protein complex that is the primary reducer of ferredoxin and the electron acceptor of plastocyanin.…”

“…The commonly used membrane proteinstabilizing surfactants, DM and OG, did not stabilize the Ϸ735-nm complex with the Ϸ685-nm spectroscopic shift. However, before drying the sample, addition of the peptide surfactant Ac-AAAAAAK (A 6 K) at an increasing concentration significantly stabilized the PSI complex (36). Moreover, in the presence of the A 6 K peptide surfactant, the PSI complex is stable in a dried form at room temperature for at least 3 weeks (36,37).…”

“…However, before drying the sample, addition of the peptide surfactant Ac-AAAAAAK (A 6 K) at an increasing concentration significantly stabilized the PSI complex (36). Moreover, in the presence of the A 6 K peptide surfactant, the PSI complex is stable in a dried form at room temperature for at least 3 weeks (36,37). Another peptide surfactant, Ac-VVVVVVD (V 6 D), also stabilized the complex, but to a lesser extent.…”

Perspectives for Photobiology in Molecular Solar Fuels

“…A second approach outlined in this paper is artificial photosynthesis, whereby protein scaffolds localise pigments to capture solar energy in artificial photosynthetic reaction centres. The photochemistry of a reaction centre can generate electricity [7] or preferably a molecular fuel with the incorporation of an enzymatic catalyst (Fig. 1).…”