Orthogonally dual-clickable Janus nanoparticles via a cyclic templating strategy.

Synthetic asymmetrical systems, Janus particles and patchy particles, are capable of undergoing hierarchical assembly processes that mimic those of Nature, to serve as switchable devices, optical probes, phase-transfer catalysts, and multifunctional drug carriers, each of which benefits from opposing surface patterns that behave differently. Production of nanometer-sized Janus particles that are equipped with efficient chemistries remains a challenge. A robust Janus-faced polymer nanoparticle framework that presents two orthogonally click-reactive surface chemistries has been generated by a recyclable strategy that involves reactive functional group transfer by templating against gold nanoparticle substrates. This anisotropic functionalization approach is compatible with a wide range of soft materials, providing Janus nanoparticles for the construction of dual-functionalized devices by accurately controlling chemical functionality at the nanoscopic level.