Nanoparticles surface energy transfer

Fig. 21. In vivo diagnostic application of hyaluronic acid immobilized gold nanoprobes. (A) The fluorescence quenching by nanoparticle surface-energy transfer between Hilyte-647 dye labelled oUgo-HA and gold nanocluster (left) is followed by fluorescence recovery after addition of reactive oxygen species/HAdase which release the dye labeled oUgo-HA fragments. (B) Tail vein injection of GNPs capped with HA conjugates labelled with Hilyte-647 in normal (up) and arthritis (bottom) mice. Adapted from Ref 103. (See Color Plate 43.)...

Griffin, J. Ray, R C. Size- and distance-dependent nanoparticle surface-energy transfer (NSET) method for selective sensing of hepatitis C virus RNA. Chemistry, 2008, 75(2), 342-351. 

Figure 16.12 Dipole-surface energy transfer from a fluorescein moiety (FAM) appended to ds-DNA of length R with a gold nanoparticle (d= 1.4 nm) appended to the other end. The flexible C6-linker causes a cone of uncertainty (SR) for both moieties. Addition of the coRI DNA methyl transferase (M. coRI) bends the ds-DNA at its GAATTC site by 128°, producing a new effective distance R. (Reproduced with permission from C. S. Yun et al., 2005. J. Am. Chem. Soc. 127 3115 3119. Cop5fright 2005 American Chemical Sodely.)...

Figure 16.14 Comparison between (a) Forster energy transfer, surface energy transfer and (b) plasmon resonance, a (1) Forster energy transfer, ro = 5 nm (2) surface energy transfer, to = 5 nm (3) ro = 10nm. b Plasmon resonance, (1) D (diameter of both gold nanoparticles) = 20 nm, (2) D = 40ntn, (3) ) = 60nm, (4) > = 80nm, lti=0.18 k2 = 0.23 (according to Reference 36).

Gold Nanoparticle Based Surface Energy Transfer Probe for Accurate Identification of Biological Agents DNA... 

G. K. Darbha, A. Ray and R C. Ray, Gold nanoparticle-based miniaturized nanomaterial surface energy transfer probe for rapid and ultrasensitive detection of mercury in soil, water, and fish, ACS Nano, 1(3), 208-214 (2007). 

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... 

The PAH polymeric layer played an important role in our fluorescence sensor design. First, its positive charges enabled the deposition of anionic dextran that was labeled with the pH indicator fluorescein on the surface of the nanoparticles. More importantly, the PAH polymeric layer separated between the fluorescein molecules and the metal particle. In fact, the thickness of the polymeric layer was over 10 nm, which is larger than the Forster distance required for efficient energy transfer between the fluorophore and the metallic gold particles. 

Finally, it should be noted that singlet-state lifetimes in [Re(L)(CO)3(bpy)], are long enough to allow for ultrafast electron or energy transfer in supramolecular assemblies, at surfaces or molecule/nanoparticle interfaces, see Sect. 7.3. Indeed, a hot electron injection has been seen with Ti02 nanoparticles [42] or in Re-labeled redox proteins [43],... 

Instrumental application of surface-plasmon-enhanced fluorescence was applied in using a TP scanning tunneling microscope [363], This was employed to probe the TP excited fluorescence from organic nanoparticles adsorbed on a silver surface. A size dependence of fluorescence enhancement and photodecomposition was reported as a result of competition between surface-plasmon-enhanced TP fluorescence and nonradiative energy transfer from the excited dye molecules to the silver surface. The schematic experimental setup is shown in Figure 3.14 [363]. 

The enhancement can be explained also by an excitation transfer from Si nanocrystallites to Eu ions. Other authors [10] have shown similar results by comparing the PL of Eu in silica gel and in silica gel with colloidal cadmium sulfide. They show that CdS nanoparticles enhanced Eu fluorescence due to energy transfer from a surface trap in the CdS particles to Eu ions. 

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