Effect of Dimensionality on RET

Equation (9.29) for Forster kinetics is valid for randomly distributed acceptors in an infinite volume, i.e. in three dimensions. If the dimension is not 3, but 1, or 2, Eq. (9.29) must be rewritten in a more general form  

Only a few studies of RET in one dimension - between dyes intercalated into DNA - have been reported. 

RET in two dimensions has been studied in monolayers, Langmuir-Blodgett films and phospholipid bilayers of vesides. In particular, RET provides a very useful tool for the investigation of biological membranes, as exemplified in Box 9.2. 

In media of fractal structure, non-integer d values have been found (Dewey, 1992). However, it should be emphasized that a good fit of donor fluorescence decay curves with a stretched exponential leading to non-integer d values have been in some cases improperly interpreted in terms of fractal structure. An apparent fractal dimension may not be due to an actual self-similar structure, but to the effect of restricted geometries (see Section 9.3.3). Another cause of non-integer values is a non-random distribution of acceptors. 

---

Hrior to examining experimental data, it is of interest to examine the forms of the dontar decays. The effects of dimensionality on RET are shown using simulated data in Figure 15,6.1 these simulations, the acceptor concentrations were taken aa eqnal to the values of Co, which allows... 

---