The direct chemical vapour deposition (CVD) of freestanding graphene gyroids with controlled sub-60 nm unit cell sizes is demonstrated. Three-dimensional (3D) nickel templates were fabricated through electrodeposition into a selectively voided triblock terpolymer. The high temperature instability of sub-micron unit cell structures was effectively addressed through the early introduction of carbon precursor, which stabilizes the metallized gyroidal templates. The as-grown graphene gyroids are self-supporting and can be transferred onto a variety of substrates. Furthermore they represent the smallest free standing graphene 3D structures yet produced with a pore size of tens of nm, as analysed by electron microscopy and optical spectroscopy. We discuss the generality of our methodology for the synthesis of other types of nanoscale, 3D graphene assemblies and the transferability of this approach to other 2D materials.

The macroscopic elastic modulus and yield strength of solid-wall nickel gyroids and hollow-wall graphene gyroids of cell size 60 nm are deduced from indentation tests on a thin coating of the gyroids, with suitable interpretation by finite element simulations. The solid-wall nickel gyroids are fabricated by the self-assembly of a triblock copolymer, followed by the chemical vapour deposition of a graphene film onto this catalytic template. The nano-indentation response of the gyroid-based coatings was measured using a Berkovich indenter. In order to interpret the indentation response, two sets of finite element simulations were performed: periodic cell calculations in order to deduce the effective macroscopic properties in terms of the relative density and cell wall properties of the lattice, and then indentation simulations of a continuum with the effective properties of the gyroid. Despite the knockdown in modulus and strength of the graphene gyroid lattice due to waviness of the layered cell walls, the structure remains remarkably strong due to nanoscale size effects.

with different (from 0 to 6) combinations of truncated and full-length sequences. Formation of concatemers was assessed by the use of singlemolecule photobleaching and protein cross-linking. Whole-cell recordings from concatenated PANX1 constructs suggest that at least four intact C-termini are required to inhibit channel activity. In addition, as the number of intact C-termini increased, there was a progressive decrease in single channel conductance, suggesting that individual C-termini may act within the multimeric channel to inhibit channel conductance. These results provide further mechanistic insights into the regulation of PANX1 channels by the C-terminal autoinhibitory domains.