Development and applications of single particle orientation and rotational tracking in dynamic systems

Three-layer core-shell plasmonic nanorods (Au/Ag/SiO2-NRs), consisting of a gold nanorod core, a thin silver shell, and third, thin silica layer were synthesized and used as optical imaging probes under a differential interference contrast microscope for single particle orientation and rotational tracking. The localized surface plasmon resonance modes were enhanced upon the addition of the silver shell, and the anisotropic optical properties of gold nanorods were maintained. The silica coating enables surface functionalization with silane coupling agents and provides enhanced stability and biocompatibility. Taking advantage of the longitudinal LSPR enhancement, the orientation and rotational information of the hybrid nanorods on synthetic lipid bilayers and on live cell membranes were obtained