Electron transfer (ET) through proteins, a fundamental element of many biochemical reactions, is studied intensively in aqueous solutions. Over the past decade, attempts were made to integrate proteins into solid-state junctions in order to study their electronic conductance properties. Most such studies to date were conducted with one or very few molecules in the junction, using scanning probe techniques. Here we present the high-yield, reproducible preparation of large-area monolayer junctions, assembled on a Si platform, of proteins of three different families: azurin (Az), a blue-copper ET protein, bacteriorhodopsin (bR), a membrane protein-chromophore complex with a proton pumping function, and bovine serum albumin (BSA). We achieve highly reproducible electrical current measurements with these three types of monolayers using appropriate top electrodes. Notably, the current-voltage (I-V) measurements on such junctions show relatively minor differences between Az and bR, even though the latter lacks any known ET function. Electron Transport (ETp) across both Az and bR is much more efficient than across BSA, but even for the latter the measured currents are higher than those through a monolayer of organic, C18 alkyl chains that is about half as wide, therefore suggesting transport mechanism(s) different from the often considered coherent mechanism. Our results show that the employed proteins maintain their conformation under these conditions. The relatively efficient ETp through these proteins opens up possibilities for using such biomolecules as current-carrying elements in solid-state electronic devices.

A model scheme is proposed for obtaining layered compounds consisting of carbon atoms in the sp and sp 2 hybridized states. This model is used to find the possibility of existing the following seven basic structural modifications of graphyne: α , β1 , β2 , β3 , γ1 , γ2 , and γ3 graphyne. Polymorphic modifica tions β3 graphyne and γ3 graphyne are described. The basic structural modifications of graphyne contain diatomic polyyne chains and consist only of carbon atoms in two different crystallographically equivalent states. Other nonbasic structural modifications of graphyne can be formed via the elongation of the carbyne chains that connect three coordinated carbon atoms and via the formation of graphyne layers with a mixed structure consisting of basic layer fragments, such as α-β graphyne, α-γ graphyne, and β-γ graphyne. The semiempirical quantum mechanical MNDO, AM1, and PM3 methods and ab initio STO6 31G basis calcu lations are used to find geometrically optimized structures of the basic graphyne layers, their structural parameters, and energies of their sublimation. The energy of sublimation is found to be maximal for γ2 gra phyne, which should be the most stable structural modification of graphyne.

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Theoretical scheme is proposed for obtaining layered compounds consisting of carbon atoms in the sp-and sp2-hybridized states. This scheme is used to find the possibility of existing the seven basic structural modifications of graphyne: α-, β1-, β2-, β3-, γ1-, γ2-, and γ3-graphyne. The basic structural modifications of graphyne contain diatomic polyyne chains and consist only of carbon atoms in two different crystallographically equivalent states. Other nonbasic structural modifications of graphyne can be formed via the elongation of the carbyne chains and via the formation of graphyne layers with a mixed structure consisting of basic layer fragments. The geometrical optimization of the structure and the calculation of energy characteristics and electronic properties of graphyne layers were performed using ab initio calculations based on the density functional theory in the generalized gradient approximation. The energy of sublimation is found to be maximal for γ graphynes, which should be the most stable structural modifications of graphyne.