PNA-directed solution- and surface-assembly of shell crosslinked (SCK) nanoparticle conjugates

The conjugation of complementary peptide nucleic acid (PNA) sequences to well defined shell crosslinked (SCK) nanoparticles is reported as a mechanism by which to direct their self assembly into higher order structures via selective and tunable binding interactions. Base-pairing-driven aggregation of the SCK's occurred for mixtures of SCK's that presented complementary sequences in aqueous sodium chloride solutions and upon mica substrates. The assembly processes were monitored by dynamic light scattering and atomic force microscopy as a function of salt concentration, and by UV-vis spectroscopy as a function of salt concentration and temperature. Moreover, the stoichiometries of the PNA sequences conjugated per SCK nanoparticle and the stoichiometric ratios in the production of mixtures of SCK's bearing complementary PNA sequences were each altered to tune the hierarchical assemblies.