Energy transfer from surface

Figure 27 NIR luminescence from gold nanoparticles is enhanced if excitation occours via energy transfer from surface-bound fluorophores. (Reproduced with permission from Ref. 52. 2007, American Chemical Society.)...

Montalti M, Zaccheroni N, Prodi L, O Reilly N, James SL (2007) Enhanched sensitized NIR luminescence from gold nanoparticles via energy transfer from surface-bound fluorophores. J Am Chem Soc 129 2418-2419... 

Fig. 4.1.17 Graphic illustration of Forster-type resonance energy transfer from aequorin to Aequorea GFP. In the vessel at left, a solution contains the molecules of aequorin and GFP randomly distributed in a low ionic strength buffer. The vessel at right contains a solution identical with the left, except that it contains some particles of DEAE cellulose. In the solution at right, the molecules of aequorin and GFP are coadsorbed on the surface of DEAE particles. Upon an addition of Ca2+, the solution at left emits blue light from aequorin (Xmax 465 nm), and the solution at right emits green light from GFP (Xmax 509 nm).

HTAC cationic micelles also markedly enhance the CL intensity of fluorescein (FL) in the oxidation of hydrogen peroxide catalyzed by horseradish peroxidase (HRP) [39], However, no CL enhancement was observed when anionic micelles of sodium dodecyl sulphate (SDS) or nonionic micelles of polyoxyethylene (23) dodecanol (Brij-35) were used (Fig. 9). CL enhancement is attributed to the electrostatic interaction of the anionic fluorescein with the HTAC micelles. The local concentration of fluorescein on the surface of the micelle increases the efficiency of the energy transferred from the singlet oxygen (which is produced in the peroxidation catalyzed by the HRP) to fluorescein. This chemiluminescent enhancement was applied to the determination of traces of hydrogen peroxide. The detection limit was three times smaller than that obtained in aqueous solution. 

Fluorescence lifetime measurements on the aggregate have shown that the rate constant of the intermolecular energy transfer from the zinc porphyrin unit to the free-base porphyrin unit has been evaluated to be 3.0 x 109 s-1. This value is reasonable from a model in which dendritic donor 6b and acceptor 5a contact each other directly at their exterior surfaces (Scheme 2). Therefore, electrostatic assembly of positively and negatively charged dendrimers provides a promising supramolecular approach to construct photofunctional materials with nanometric precision. 

The optimal enhancement effect is observed when the localized surface plasmon resonance is tuned to the emission wavelength of a locally situated fluorophore [86]. This is consistent with the model suggesting a greatly increased efficiency for energy transfer from fluorophores to surface plasmons [78]. Since resonance energy transfer is involved, the important factors affecting the intensity of fluorescence emission must also be the orientation of the dye dipole moments relative to the... 

Kometani etal.(93) used a theory for energy transfer from a donor to acceptors in a plane to determine the location of the retinal chromophore relative to the membrane surface. Another similar study on the location of the active site of chloroplast ATPase relative to the membrane surface has also been carried out.(94)... 

W. H. Weber and C. F. Eagen, Energy transfer from an excited dye molecule to the surface plasmons of an adjacent metal, Opt. Lett. 4, 236-238 (1979). 

Brenner and Garrison introduced a potential which was derived by rewriting a valence force expression so that proper dissociation behavior is attained . Because the equations were extended from a set of terms which provided an excellent fit to the vibrational properties of silicon, this potential is well suited for studying processes which depend on dynamic properties of crystalline silicon. For example, Agrawal et al. have studied energy transfer from adsorbed hydrogen atoms into the surface using this potential . 

The heat transferred through the barrel wall over the channel, Ej, is given by Eq. 7.83. A heat transfer expression could also be written for energy transferred from the molten polymer to the barrel over the flight iand and also from the melt to the screw surface. 

Figure 27 Sensitized solar cell based on dye-loaded zeolite L antenna systems. The antenna systems absorb light and transport their energy mainly along the c axis of the crystals to the semiconductor surface. Electron-hole pairs are formed in the semiconductor by energy transfer from the antenna system to the conduction band of the semiconductor.

B12), and by Gazley (Gl), using air-water. It was shown that when a gas-liquid interface is smooth, energy transfer from gas to liquid is entirely dissipated in surface friction, but when a liquid surface is hydrodynamically rough, energy transfer from gas to liquid may amount to twice that to be expected on the basis of interfacial friction (Gl). Presumably this excess energy is dissipated in the formation and maintenance of surface waves. 

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