Fluorescence Lifetime Selectivity in Multifrequency Phase-Resolved Fluorescence Spectroscopy

Abstract

Theoretical aspects of the implementation of fluorescence lifetime selectivity in multifrequency phase-resolved fluorescence spectroscopy (PRFS) are discussed. The dependence of phase-resolved fluorescence intensities on the dynamic instrumental parameters of excitation modulation frequency and detector phase angle, as well as on fluorescence lifetime, is described. The different types of fluorescence lifetime “filtering” that can be effectively achieved include longpass, shortpass, and bandpass functions. The ability to continuously scan both modulation frequency and detector phase angle greatly increases the potential of PRFS for fluorimetric analysis.