Spectrofluorimetric measurements were performed using a PerkinElmer LS-55 luminescence spectrometer equipped with a Xenon discharge lamp, Monk-Gillieson type monochromators, and a gated photomultiplier. The acquisition of data was performed using the FL Winlab v4.00.03 software supplied by PerkinElmer.
In all cases, quartz cells with planar walls of 100 µL were used. A 5-nm slit width was used in excitation and 7 nm in emission monochromators; a 650 V detector voltage and a scan speed of 600 nm.min−1 were set. Emission spectra were recorded from 290 to 500 nm in 1-nm steps with excitation at 275 nm. The Trp emission spectra, employed as a positive control, were recorded from 310 to 500 nm in 1-nm steps with excitation at 295 nm.
In all cases, quartz cells with planar walls of 100 µL were used. A 5-nm slit width was used in excitation and 7 nm in emission monochromators; a 650 V detector voltage and a scan speed of 600 nm.min−1 were set. Emission spectra were recorded from 290 to 500 nm in 1-nm steps with excitation at 275 nm. The Trp emission spectra, employed as a positive control, were recorded from 310 to 500 nm in 1-nm steps with excitation at 295 nm.