New Frequency-Domain Fluorometer for the Rapid Determination of Picosecond Rotational Correlation Times

摘要

A new instrument is described which uses the harmonic content of a mode-locked argon ion laser for the determination of picosecond rotational-correlation times. The new instrument is very rapid, and can detect in about 8ms all frequencies between dc and 750 MHz. The signal averaging capabilities of the instrument, the time dependent fluorescence polarization of rhodamine 6G was studied as a function of solvent viscosity; a second chemical system investigated was fluorescein in 1,3-propanediol. Both these systems were chosen because they have been shown to exhibit a single rotational-correlation time. Results are in good agreement with those previously reported. Keywords: Reprints; Time resolved fluorimetry; Molecular rotation; Sensors.