Fig. 5: Self-assembly of TC-RNA tiles with built-in RNA broccoli aptamer.

a Schematics of two linear assemblies by TC-RNA tiles with built-in RNA broccoli aptamer. b, c AFM images of Array 1 and Array 2. The scale bar is 200 nm. The inset image size is 100 nm × 100 nm. d The normalized fluorescence intensities of broccoli aptamer control, Array 1 and Array 2. e Schematics of fluorescence on AB arrays self-assembly. Individual tile array assembly (Array 3 or Array 4) cannot yield a fluorescence signal. The fluorescence turns on only after mixing Array 3 and Array 4 together, and the mix is named Array 3 + 4. f Kinetic tracing of the change in fluorescence intensity for the process described in panel (e). Arrays 3 and 4 are mixed at 0 min, and the DFHBI-1T dye is added at approximately 5 min. The excitation wavelength is 470 nm, and the emission wavelength is 505 nm. g–i AFM images of Array 3, Array 4, and Array 3 + 4. The scale bar is 200 nm. j The normalized fluorescence intensity of control, Array 3, Array 4, and Array 3 + 4. For each assembled array, the same amount of RNA strands (0.5 μM) was incubated in 40 mM HEPES (pH 7.4), 100 mM KCl, 1 mM MgCl₂, and 10 μM DFHBI-1T. AFM images were captured after a 2-h annealing process from 90 °C to 25 °C. Fluorescence intensities are presented as means ± SEs from n = 6 experiments (Ex = 470 nm and Em = 505 nm).