No abstract

Aluminum-doped zinc oxide (AZO) is well known as transparent conducting material for electro-optical devices, but is rarely used as plasmonic material, particularly on the localized surface plasmon resonance (LSPR) behavior of AZO nanostructure and its plasmonic devices. In this study, we systematically investigate the plasmonic behaviors of AZO thin films and patterned AZO nanostructures with various structural dimensions under different annealing treatments. We find that AZO film can possess highly-tunable, metal-like, and low-loss plasmonic property and the LSPR characteristic of AZO nanostructure is observed in the near-infrared (NIR) region under proper annealing conditions. Finally, environmental index sensing is performed to demonstrate the capability of AZO nanostructure for optical sensing application. High index sensitivity of 873 nm per refractive index unit (RIU) variation is obtained in experiment.

We propose a novel mirror-image nanoepsilon (MINE) structure to achieve highly localized and enhanced near field at its gap and systematically investigate its plasmonic behaviors. The MINE can be regarded as a combination of two fundamental plasmonic nanostructures: a nanorod dimer and nanoring. By adapting a nanoring surrounding a nanorod dimer structure, the nanorod is regarded as a bridge pulling the charges from the nanoring to the nanorod, which induces stronger plasmon coupling in the gap to boost local near-field enhancement. Two resonance peaks are identified as the symmetric and anti-symmetric modes according to the symmetries of the charge distributions on the ring and rod dimer in the MINE. The symmetric mode in the MINE structure is preferred because its charge distribution leads to stronger near-field enhancement with a concentrated distribution around the gap. In addition, we investigate the influence of geometry on the optical properties of MINE structures by performing experiments and simulations. These results indicate that the MINE possesses highly tunable optical properties and that significant near-field enhancement at the gap region and rod tips can be realized by the gap and lightning-rod effects. The results improve understanding of such complex systems, and it is expected to guide and facilitate the design of optimum MINE structures for various plasmonic applications.

Platinum(II)-sulindac complexes [{η -C H SN(O)}Pt(DMSO){O(C=O)Sulindac}], [{η -C H SN(O)}PtCl{(S=O)Sulindac}], [{η -C H SN(O)}PtCl{(S=O)Sulindac-succinimide}], and [{η -C H SN(O)}PtCl{(S=O)Sulindac-thymidine}] were synthesized that exhibited IC values of 2.9-4.8 μm against human oral cancer cells OECM1. The poly(lactic-co-glycolic acid) (PLGA) encapsulated [{η -C H SN(O)}PtCl{(S=O)Sulindac}] also showed cytotoxic activity although less potent than the pristine species.