Abstract

For the understanding of photophysical and photochemical processes of nucleic adds and their bases in aqueous solutions including in vitro or in vivo, their excited-state studies are essential. Furthermore, the knowledge from these studies may be useful for a DMA sequential analysis without fluorescent probes. However, their very low fluorescence quantum yields (10⁻⁴ – 10⁻⁵) and very short excited-state lifetimes (10⁻¹² – 10⁻¹³ s)¹ have hampered the progress of their studies. In order to solve these problems, we developed a picosecond time-resolved UV emission spectrometer using the nonlinear frequency-conversion UV pulses (270 run, ~ 200 fs) of a femtosecond Ti:sapphire laser and a highly sensitive synchroscan streak camera. We demonstrate for the first time, to our knowledge, that the apparatus enables us to clarify the emission relaxation mechanisms of guanine (G), guanosine (GS) and guanosine monophosphate (GMP) aqueous solutions at room temperature.

© 1996 Optical Society of America