Abstract

The determination of fluorescence lifetime requires only relative intensity measurements and so is especially useful for biomedical samples in which the heterogeneous nature of tissue and autofluorescence present significant problems Since fluorescence lifetime is dependent upon both radiative and non-radiative decay rates, it may be used to distinguish between different fluorophore molecules (with different radiative decay rates) and to monitor local environmental perturbations that affect the non-radiative decay rate. Fluorescence lifetime probes have been demonstrated for many biologically significant analytes including [O₂], [Ca²⁺] and pH.¹ Fluorescence lifetime imaging (FLIM) can be applied to almost any optical imaging modatity, including microscopy and potentially to non-invasive optical biopsy².

© 2000 IEEE