Plasmonic Switches Fabricated via DNA Origami for Reconfigurable Logic Architectures

This paper reports the fabrication of DNA origami-directed plasmonic logic gates based on the site-specific assembly of silver nanoparticles (AgNPs) to nanoscale optical computing, providing a path to high-performance and reliable computing. The colloidal stability is shown by size-controlled formation of AgNPs, giving a mean diameter of 24.5[Formula: see text]nm ± 4.2[Formula: see text]nm and a plasmonic resonance peak at 412[Formula: see text]nm. Using the caDNAno designer, such DNA origami scaffolds had [Formula: see text]95 folding efficiency, produced relatively well-defined 90[Formula: see text]nm (length) by 60[Formula: see text]nm (width) rectangular structures, as visualized by AFM and confirmed by gel electrophoresis. Thiol-DNA hybridization allowed anchoring the AgNPs on defined capture surfaces of the origami with nanometric accuracy (in the range of 2[Formula: see text]nm) and high anchor efficiency (88.3% ± 3.4%). The implementation of four logic gate configurations, namely AND, OR, NOT and XOR, was carried out. The largest shift of 15.2[Formula: see text]nm ± 1.1[Formula: see text]nm was observed in the AND gate after being activated by dual input, and selective single-input activation of 13.6[Formula: see text]nm ± 1.2[Formula: see text]nm was seen in XOR gates. All the gates produced [Formula: see text]% output fidelity and maintained switching time of 5.8–8.4[Formula: see text]s using high signal-to-noise ratios ([Formula: see text]20:1). Crosstalk ([Formula: see text]3[Formula: see text]nm) and error rates (4.2 ± 0.8) were low under stress when large origami patterns were multigate integrated. These results open a sustainable and scale-up platform of photonic logic functions at the molecular scale.