Energy transfer from fluorophore to fluorophore

(Förster-Transfer)

 

Scheme :       D    +        hn₁    -->      D*

                      D*   +        A       -->       A*     +     D

                      A*   -->      A       +         hn₂

 

Transfer rate:

 

k_t = (1/ t) . [R/R_o] ^-6

 

                                  R = distance donor / acceptor

                                  Ro = critical donor / acceptor - distance ( about 1-5 nm)

                                  t =fluorescence life time

 

Interaction energy of 2 dipoles = prop. R^-3

Probability of energy transfer = prop. energy²

 

Transfer efficiency (E_t)

E_t = R_o⁶ / (R⁶ + R_o⁶)