Time-resolved fluorescence experiments were made using the time-correlated single photon counting technique. The excitation source was a pulse titanium-sapphire laser Tsunami 3950 pumped by a Millena Xs laser, both from Spectra Physics, with 5 ps pulse width at the half height and 8.0 MHz frequency, controlled by the pulse picker 3980 from Spectra Physics. The excitation wavelengths were obtained by the BBO (GWN-23PL from Spectra Physics) crystal. The measurements were made with a FL9000 spectrometer from Edinburgh, adjusted in an ‘L’ configuration with the excitation source. The wavelengths for measurement were selected by a monochromator and the detection was made by a Hamamatsu R3809U photomultiplier. The average time response of the instrument was 100 ps.
The PPh, QD and BSA stock solutions were prepared in phosphate buffer (pH 6.8, 7.5 mM). All experiments were realized at room temperature (24 ± 1) °C.
The experimental data were treated using OriginPro 8 commercial program. All final values were average of three independent experiments.
The PPh, QD and BSA stock solutions were prepared in phosphate buffer (pH 6.8, 7.5 mM). All experiments were realized at room temperature (24 ± 1) °C.
The experimental data were treated using OriginPro 8 commercial program. All final values were average of three independent experiments.