Fabrication and near-infrared optical responses of 2D periodical Au/ITO nanocomposite arrays

Two-dimensional(2D) periodical Au and indium tin oxide(ITO) nanocomposite arrays have been fabricated based on a self-assembled nanosphere lithography technique. A button-shaped Au nanoparticle was formed on each hollow hemisphere-shaped ITO shell. Importantly, the underlying formation mechanism during the thermal treatment has been thoroughly explored by comparing structures resulting from different deposition conditions in detail. Compared to the Au nanoparticle arrays without ITO shells, the Au/ITO nanocomposite arrays showed a stronger localized surface plasmon resonance effect and higher absorption in the near-infrared(NIR) region, benefiting from the free-electron interaction enhancement between Au and ITO. The nonlinear optical properties were investigated using a modified femtosecond intensity-scan system, and the results demonstrated Au/ITO nanocomposite arrays with a remarkable two-photon absorption saturation effect for femtosecond pulses at 1030 nm. The versatile NIR optical responses indicate the great potential of the elaborately prepared 2D periodical Au/ITO nanocomposite arrays in many applications such as solar cells, photocatalysis,and novel nano optoelectronic devices.

Generic synthesis and versatile applications of molecularly organic-inorganic hybrid mesoporous organosilica nanoparticles with asymmetric Janus topologies and structures

Precise control over the morphology,nanostructure,composition,and particle size of molecularly organic-inorganic hybrid mesoporous organosilica nanoparticles （MONs） still remains a major challenge,which severely restricts their broad applications.In this work an efficient bridged organic group-determined growth strategy has been proposed for the facile synthesis of highly dispersed and uniform MONs with multifarious Janus morphologies,nanostructures,organic-inorganic hybrid compositions,and particle sizes,which can be easily controlled simply by varying the bridged organic groups and the concentration of bis-silylated organosilica precursors used in the synthesis.In addition,the formation mechanism of Janus MONs determined by the bridged organic group has been discussed.Based on the specific structures,compositions,and asymmetric morphologies,all the synthesized Janus MONs with hollow structures （JHMONs） demonstrate excellent performances in nanomedicine as desirable drug carriers with high drug-loading efficiencies/capacities,pH-responsive drug releasing,and enhanced therapeutic efficiencies,as attractive contrastenhanced contrast agents for ultrasound imaging,and as excellent bilirubin adsorbents with noticeably high adsorption capacities and high blood compatibilities.The developed versatile synthetic strategy and the obtained JHMONs are extremely important in the development and applications of MONs,particularly in the areas of nanoscience and nanotechnology.