Photovoltaic Activity of Photosystem I-Based Self-Assembled Monolayer

Abstract

The photoelectronic nature of a dried photosystem I protein attached to a metal surface is studied using various spectroscopic techniques. The proteins are found to be optically active after the chemical adsorption. In addition, energy-resolved photoelectronic measurements indicate that the interaction of photosystem I with the metal surface leads to new molecule/substrate states, yielding energy states different from those of the individual components. Such interactions increase the spectral-response range beyond the absorption spectrum of photosystem I and are expected to improve the energy-conversion efficiency of devices based on this system.

Spatial modulation of light transmission through a single microcavity by coupling of photosynthetic complex excitations to surface plasmons

“…The PS I used in this study, derived from cyanobacterial membrane, is a nanosize protein-chlorophyll complex, which integrates 96 chlorophyll and 22 carotenoid pigment molecules in a helical protein membrane complex. It harvests photons with a quantum efficiency of B1, and was found to be stable and photoactive when adsorbed in a dry environment 19,[26][27][28] . Selfassembled mono and multilayers of PS I were fabricated by formation of a direct sulfide bond between unique cysteine mutants in PS I and the patterned Au surface (see Fig.…”

“…2a,b, Supplementary Fig. 1 and Methods section) 19 . The advantage of this technique compared with spin coating, in which the entire hole is covered with the thick organic layer, is that here the surface of the metal and the slit circumference are fully coated with only a thin (few tenths of nanometre) organized organic layer, leaving the majority of the slit void (Fig.…”

“…Of a special interest is the photosynthetic light harvesting complex, photosystem I (PS I) [18][19][20][21][22] . Photosynthetic complexes are evolutionary tuned to efficiently capture solar light.…”

Functional Nanohybrid Materials from Photosynthetic Reaction Center Proteins

“…6 nm inside the protein and creates approximately 1 V surface potential difference [48]. From this value, one can estimate about 1 V/ 6 nm = 1.6 ⋅ 10 8 V/m electric field [49,50]. This value is commeasurable with the membrane potential created by the work of active membrane pumps.…”

“…For this purpose, PS I is a very promising material because of its relatively large structural stability and larger absorption cross section (compared to PS II core); also, it is easier to handle in laboratory investigations [49,81]. PS I can be attached to carrier surfaces either in dry monolayer form through specific chemical binding [49] or through self-assembled mono-or multilayer structures [50]. After the binding, the functional integrity, orientation, and the efficient electronic junction with the carrier matrices are secured.…”