Extended Data Fig. 1: Rational design for the length of PEG linkers to provide an appropriate space in the subsequent Au overgrowth step.
a, AFM image (top) and AFM height scan (bottom) of a PtSNR. The measured height of PtSNR is similar to its thickness as ca. 18 nm, which enables it to be considered as a torus structure. b,c, TEM image of a PtSNR (b) and imaginary position of the other PtSNR that will form pre-interlocked entwined conformation after EDC/sulfo-NHS coupling (c). The cross section of PtSNR is expressed as a circle (dotted line) in the way that the PtSNR can be considered as a split torus structure. The diameter of 15 nm is the average value of the thickness and height. The scale bar indicates 20 nm. d, Cross section of AuNCat and the amide linker between two constituent gold nanorings. 17 nm of carboxylic PEG and amine-PEG should be used to acquire roughly 35 nm of linker that guarantees a proper interparticle distance. e,f, Possible mechanisms of the PtSNR assembly (e) and Au overgrowth-based ring-closing step (f).
