Human serum albumin-flavonoid interactions monitored by means of tryptophan kinetics.

A nonextensive model of decay kinetics has been used to describe fluorescence behavior of tryptophan in human serum albumin on binding two flavonoids, quercetin and morin. We demonstrate that this approach, alternative to multiexponential representation of usually complex decays of tryptophan, is more adequate and can be beneficial in noninvasive lifetime sensing based on intrinsic fluorescence.