DNA-Mediated Size-Selective Nanoparticle Assembly for Multiplexed Surface Encoding.

Multiplexed surface encoding is achieved by positioning two different sizes of gold nanocubes on gold surfaces with precisely defined locations for each particle via template-confined, DNA-mediated nanoparticle assembly. As a proof-of-concept demonstration, cubes with 86 and 63 nm edge lengths are assembled into arrangements that physically and spectrally encrypt two sets of patterns in the same location. These patterns can be decrypted by mapping the absorption intensity of the substrate at λ = 773 and 687 nm, respectively. This multiplexed encoding platform dramatically increases the sophistication and density of codes that can be written using colloidal nanoparticles, which may enable high-security, high-resolution encoding applications.