Forster resonance energy transfer states

Forster, Th 211, 278, 282, 285 Forster resonance energy transfer, 282 Forster singlet energy transfer, 378 Franck-Condon factors, 23 Franck-Condon principle, 5 Franck-Condon transition, 5 French, C. S., 555 Friedman, G., 353 Fritzsche, J., 37 Frosch, R. P 252, 267, 269 Fumaronitrile, photodimerization in solid state, 478... 

The lifetime of the excited state of fluorophores may be altered by physical and biochemical properties of its environment. Fluorescence lifetime imaging microscopy (FLIM) is thus a powerful analytical tool for the quantitative mapping of fluorescent molecules that reports, for instance, on local ion concentration, pH, and viscosity, the fluorescence lifetime of a donor fluorophore, Forster resonance energy transfer can be also imaged by FLIM. This provides a robust method for mapping protein-protein interactions and for probing the complexity of molecular interaction networks. 

Fluorescence (or Forster) resonance energy transfer (FRET) is a process by which energy is transferred nonradiatively from an excited donor to a nearby ground state acceptor. This process arises due to dipole-dipole interactions and is... 

We have developed the splinted RNA ligation procedure outlined in this chapter to generate site-specifically dye-labeled telomerase RNA constructs. These modified telomerase RNA constructs may be used to characterize dynamic RNA structural properties using Forster resonance energy transfer (FRET) (Stone et al., 2007). Our laboratory specializes in single molecule FRET measurements, which facilitates the direct observation of transient RNA structural states. The details of single molecule FRET... 

It is useful in discussion of weak coupling between nanostructures to remember the nonradiative mechanism of Forster resonant energy transfer from an excited molecule (a donor) to some other molecule (an acceptor) which can be in the ground or in an excited state. The probability of such a transfer is determined by the Coulomb nonretarded (instantaneous) dipole-dipole interaction between molecules and is proportional to Rp/R6 where Rp is the Forster radius and R is the distance between molecules. For organic materials the Forster radius is usually about several nanometers and strongly depends on the overlapping... 

Forster s theory is also behind the FRET method (Forster resonance energy transfer or fluorescence resonance energy transfer). In this case, excitation takes place with a narrow laser pulse, corresponding to the lowest excited state of a chromo-phore. The rate of EET is determined by time-resolved fluorescence. 

Mor GK, Basham J, Paulose M, Kim S, Varghese OK, Vaish A, Yoriya S, Grimes CA (2010) High-efficiency Forster resonance energy transfer in solid-state dye sensitized solar cells. Nano Lett 10(7) 2387-2394... 

Forster (1968) points out that R0 is independent of donor radiative lifetime it only depends on the quantum efficiency of its emission. Thus, transfer from the donor triplet state is not forbidden. The slow rate of transfer is partially offset by its long lifetime. The importance of Eq. (4.4) is that it allows calculation in terms of experimentally measured quantities. For a large class of donor-acceptor pairs in inert solvents, Forster reports Rg values in the range 50-100 A. On the other hand, for scintillators such as PPO (diphenyl-2,5-oxazole), pT (p-terphenyl), and DPH (diphenyl hexatriene) in the solvents benzene, toluene, and p-xylene, Voltz et al. (1966) have reported Rg values in the range 15-20 A. Whatever the value of R0 is, it is clear that a moderate red shift of the acceptor spectrum with respect to that of the donor is favorable for resonant energy transfer. 

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