3D Confined Assembly of Polymer-Tethered Gold Nanoparticles into Size-Segregated Structures

Abstract

We demonstrate a co-assembly of polystyrene (PS)-tethered gold nanoparticles (GNPs) with different sizes under 3D confinement. Interestingly, core-shell assemblies with particle size segregation were obtained, and location/arrangement of GNPs can be effectively tuned by tailoring chain length of PS ligands. Typically, short PS-tethered GNPs locate at outer layers while long PS-tethered GNPs accumulate in the interior because of hydrophilicity difference between them. Binary GNPs-based core-shell structures were clearly confirmed by transmission electron microscopy tomography and the formation mechanism was intensively explored. This fabrication approach is applicable to NPs with different sizes, shapes and types. Moreover, both UV-Vis absorption spectra and photothermal conversion efficiencies of the GNP assemblies can be effectively regulated by adjusting PS chain length and content ratio, thus facilitating their biomedical applications in osteosarcoma therapy.