Orientation of photosystem I on graphene through cytochrome c₅₅₃ leads to improvement in photocurrent generation

Abstract

Orienting photosystem I on single-layer graphene improves photocurrent generation.

Photosystem I Multilayers within Porous Indium Tin Oxide Cathodes Enhance Mediated Electron Transfer

“…Within the meso‐ITO, the ITO nanoparticles pack randomly and densely, forming pore sizes between 20 and 100 nm (Figures A and 2B). These mesopores are on the scale of the crystallographic PSI protein complex unit cell dimensions, approximately 12×13×19 nm . The meso‐ITO electrodes have a thickness of 4.6±1.3 μm via profilometry (Figure S3A), and the dense porous structure extends uniformly to the substrate surface, as shown in the cross‐sectional SEM (Figure C).…”

“…ITO nanoparticles were utilized to produce two different three‐dimensional electrode morphologies, mesoporous and macroporous ITO (meso‐ITO and macro‐ITO). The meso‐ITO electrodes bear cavities of approximately 20–100 nm, which is slightly larger than the crystallographic dimensions of the PSI protein complex and is hypothesized to increase the PSI‐ITO contact area . Macro‐ITO prepared via an ITO‐coated polystyrene templating procedure (Figure S1) provided much larger pore sizes (∼5 μm) and a hierarchical pore structure where the macropore walls are also mesoporous due to their composition of sintered ITO nanoparticles.…”

“…[6][7][8] To enable DET, monolayers of PSI protein complexes have been coupled with various linking molecules and proteins, which help minimize the electrodeprotein separation distance and also provide an energetically favorable pathway for electron transfer. [7,[14][15][16][17][18][19][20][21][22][23][24] Most notably, the cytochrome complex (cyt c) has been used to attach PSI onto a variety of electrode materials. [7,[14][15][16][17][18][19][20][21][22][23][24] Alternatively, significant improvements in mediated photocurrent generation have been achieved by drop-casting thick multilayer films of PSI onto silicon, gold, and graphene electrodes.…”

“…[7,[14][15][16][17][18][19][20][21][22][23][24] Most notably, the cytochrome complex (cyt c) has been used to attach PSI onto a variety of electrode materials. [7,[14][15][16][17][18][19][20][21][22][23][24] Alternatively, significant improvements in mediated photocurrent generation have been achieved by drop-casting thick multilayer films of PSI onto silicon, gold, and graphene electrodes. [5,[25][26][27] Applying thicker films of PSI improves overall light absorption by providing a higher areal protein loading and increasing the total amount of converted mediator.…”

“…The meso-ITO electrodes bear cavities of approximately 20-100 nm, which is slightly larger than the crystallographic dimensions of the PSI protein complex and is hypothesized to increase the PSI-ITO contact area. [16] Macro-ITO prepared via an ITO-coated polystyrene templating procedure ( Figure S1) provided much larger pore sizes (~5 μm) and a hierarchical pore structure where the macropore walls are also mesoporous due to their composition of sintered ITO nanoparticles. The electrochemically active surface area of both electrode morphologies was determined via cyclic voltammetry (CV).…”