Surface Plasmon Resonance in Nanocrystalline Gold–Copper Alloy Films

Abstract

Nanocrystalline Au(x)Cu(1-x) films were synthesized by depositing Cu/Au/Cu multilayer in nanocrystalline thin film form with requisite thickness of individual layers onto fused silica substrates by high pressure sputtering technique. The absorbance spectra showed only one surface plasmon peak for all the compositions with the exception that the peak position did not indicate gradual shift as gold concentration was increased. Peak position for the two compositions corresponding to the two superlattice structures, AuCu3 and AuCu, deviated significantly from linear variation. The experimental results have been discussed in light of the existing Mie theory and the Core-shell model.

Targeting the Bcl-2 family for cancer therapy

“…Additionally, Schwickart et al demonstrated that in hematologic malignancies 51 , the expression of deubiquitinase USP9X expression correlates with that of Mcl-1, and USP9X binds to Mcl-1, stabilizes it and thereby promotes Mcl-1 overexpression and cell survival. Recent studies showed that in B-cell malignancies, patients treated with the anti-CD20 antibody rituximab exhibited an increased level of Mcl-1 52 . Mcl-1 downregulation using RNA interference sensitized these cells to rituximab treatment 52 , underscoring the importance of Mcl-1 as a mediator of chemotherapy resistance.…”

“…Recent studies showed that in B-cell malignancies, patients treated with the anti-CD20 antibody rituximab exhibited an increased level of Mcl-1 52 . Mcl-1 downregulation using RNA interference sensitized these cells to rituximab treatment 52 , underscoring the importance of Mcl-1 as a mediator of chemotherapy resistance.…”

Plasmonics for Improved Photovoltaic Devices

“…In recent years, it has been indicated [15][16][17][18][19][20][21][22] that both shape and size of metal nano particles are key factors determining the coupling efficiency. Moreover, the plasmon energy can be efficiently collected and transferred to an underlying waveguide as part of a solar cell.…”

“…The plasmons can be considered as a sort of proxy for the light, except at a shorter wavelength. A flurry of experimental and theoretical activities over the past few decades [15][16][17][18][19][20][21][22][23][24][25][26] was devoted towards the understanding of the size and shape effects, broadening, effect of surrounding matrix, etc., on the surface plasmon band of gold, silver and its nano composites. The surface plasmon resonance largely depend on the particle size, shape, and of course the metallic material and its surrounding environment.…”

“…Although metal doping in another exotic dielectric medium, diamond like carbon (DLC) films, prepared by chemical/ physical vapour deposition techniques had been the issue of obtaining a new class of materials [15][16][17][18][19][20][21][22][23][24][25][26] but the difficulty of dispersing the metal particles homogeneously in the DLC matrix by the techniques used by the researchers was found to be difficult. Since DLC is a large band gap material, metal inclusion in nanocrystalline form should also reveal interesting optical properties like surface plasmon resonance in these classes of composite materials which have not been explored yet systematically.…”