ABSTRACT
Calculating the time-dependent fluorescence F(t)meas for different modes of measurement, Box 11.1 describes the basic convolution integral that is our starting point for the description of all time-dependent fluorescence experiments. Equation 11.1 simply says that the fluorescence signal at time t depends on all excitation events previous to t (causality), and the fluorescence response is the linear sum (integral) of all the prior excitation events. Equation 11.2 states that if fluorophores are excited instantaneously at time t′, then the fluorescence will decay exponentially as (t – t′) (Clegg and Schneider 1996; Clegg, Schneider, and Jovin 1996). The defining parameters in the fluorescence decay are the amplitudes, F0,i and the lifetimes τi (see Box 11.1). The amplitudes carry information concerning the number of fluorophores that have been excited, and each lifetime provides valuable physical information about all the participating pathways of de-excitation for that particular fluorescence species, as described in Chapter 1.
