We have used a high-repetition-rate, pulsed, 266nm microchip laser and a low-repetition-rate, frequency doubled, tunable dye laser (266nm) to study the fluorescence lifetime of the line spectra of terbium doped dipicolinate in distilled water. Our results are related to the detection of endospores in the environment.
Terbium-dipicolinic acid can be used to enhance the UV fluorescence detection of selected biological agents and endospore cells. We are using new tunable UV laser near 220nm-280nm to optimize the excitation wavelength and detection sensitivity, and studying the acid solution/buffer mix to optimize the fluorescence yield. Enhancements on the order of a factor of 20 have been observed so far.