Surface plasmon spectrum

For silver complexed by CN , the surface plasmon spectrum of clusters develops with a maximum close to 395 nm, similar to that of hydrated clusters without ligand, but with a higher extinction coefficient per atom 395 (Ag cn") =... 

To determine if the resonance peak is due to self-organization, optical spectra of disorganized nanocrystals (see TEM pattern inset Fig. 8) are recorded under v- and p-polar-ization. Under v-polarization, the optical spectrum obtained at 0 = 60° (Fig. 8A) shows one resonance peak at 2.7 eV. This is attributed to the surface plasmon parallel to the substrate. 

The final silver cluster diameter increases, at given initial Ag and PVA concentrations, for example from 15 to 50 nm (n 50 times larger), when the part of reduction is increasingly achieved by the donor SPV, rather than by radiolytic radicals [31]. A red shift correlates with the growth in size in the final optical surface plasmon band. Nonirradiated solutions of EDTA silver complex are stable because EDTA does not reduce the ions directly. However, after the appearance of the 400-nm spectrum of silver... 

The same evolution of the absorption spectrum with the dose has been found in a high dose rate for various values of the Ag and Au ion fraction in the initial solution. Clusters Agi. Au are alloyed with the same composition. The maximum wavelength and the extinction coefficient Smax of the alloy depend on x. The experimental spectra are in good agreement with the surface plasmon spectra calculated from the Mie model at x values for which optical data are available (Fig. 12) [102]. Similar calculations were carried out for the alloy Ag Pdi obtained at a moderate dose rate [180]. 

Another example listed in the table is graphite, the Frohlich mode of which is near 5.5 eV (2200 A) the boundaries of the negative e region are about 4 and 6.5 eV. The graphite surface plasmon has been tentatively identified as responsible for a feature in the interstellar extinction spectrum (see Section 14.5). 

Figure 20-23 (a) Surface plasmon resonance spectrum of sensor coated with molecularly imprinted polymer that selectively binds NAD+. (b) Response of sensor to four similar molecules shows largest response to NAD+, which was the template for polymerization. [From O. A. Raitman. V. I. Chegel, a B. Kharitonov. M. Zayats. E. Katz, and I. Winner. Analysis of NAD(P) and NAD(P)H Cofactors by Means of Imprinted Polymers Associated with Au Surfaces A Surface Plasmon Resonance Study. Anal. CNm. Ada 2004,504. 101.]... 

Fig. 13. (A) Schematic representation of the interaction between neighboring residues of the His-tag (6 consecutive Histidine residues) and an NTA-complexed Ni2+ ion. (B) The performance of LHCII immobilization via chelating interaction. SPR kinetic curve of LHCII immobilization and regeneration cycles, monitored with an Nd YAG DPSS laser (X = 473 nm). (C) Surface plasmon field-enhanced fluorescence emission spectrum of surface attached LHCII compared with the fluorescence emission from free LHCII in solution, excited by an Nd YAG DPSS laser (X — 473 nm).

Figure 26. XPS data in the carbon 1 s region for a UHV cleaved graphite reference (HOPG) and a carbon black sample used in the titration experiments of Fig. 25. The arrow marks the position of the graphite surface plasmon. The top section of the modified spectrum in the high-binding energy side reveals several weak peaks for oxygen functional groups after removal of the asymmetric line profile from the main peak.

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