Fig. 2: Structures of NP cluster architectures assembled by programmed meshframe and revealed by TEM and cryo-TEM tomography.

a (From top to bottom) Designed DNA meshframes with different valence numbers: two, three, four, five, and six, corresponding to the geometry of dumbbell, triangle, square, TBP and octahedra, respectively. b NPs decorated with DNA are assembled into clusters, whose architecture is determined by the meshframe valence mode. c Representative negative-stained TEM images of assembled NP clusters based on meshframes with different valence modes; scale bar, 100 nm (insets: zoomed-in images; side length, 70 nm). d NP cluster population histograms. e Reconstructed 3D structure of TBP cluster from cryo-TEM based tomography (top). Designed center-to-center distances between NPs (bottom, shadow columns): d₁ = 64.8 nm, d₂ = 56.1 nm, and d₃ = 45.8 nm. Measured distances between NPs of one reconstructed cluster (bottom, solid columns): d₁ = 64.6 nm, d₂ = 55.8 ± 2.7 nm, and d₃ = 46.1 ± 2.1 nm. f Reconstructed 3D structure of octahedral cluster by cryo-TEM tomography (top). Designed NP distances (bottom, shadow columns): d₁ = 64.8 nm and d₃ = 45.8 nm, and measured cryo-TEM tomography distances averaged over two independently reconstructed clusters (bottom, solid columns): d₁ = 66.3 ± 2.0 nm and d₃ = 46.9 ± 3.8 nm. Error bars indicate standard deviation of experimental data.