Frequency-domain fluorescence spectroscopy using 280-nm and 300-nm light-emitting diodes: measurement of proteins and protein-related fluorophores.

In the past few decades, Xuorescence methods havebecome extremely important in many areas of scienceand technology including analytical chemistry, biophys-ics, cell biology, clinical chemistry, and biotechnology, toname but a few. Determinations of the excited-state life-times of Xuorescent molecules are often critical for quan-titative evaluation of the processes or reactions ofinterest. Fluorescence lifetime measurements have tradi-tionally been realized using either the