The PL decay curves of the solution and gel were
measured with picosecond-pulsed laser excitation at 405 nm (10.0 MHz,
90 ps full width at half-maximum) under an inverted confocal microscope
(Olympus, IX-71). The beam was reflected by a dichroic mirror (Semrock,
Di01-R405) and then focused to the sample in a quartz cuvette on a
sample stage by an objective lens (Olympus, 20×, NA 0.4), and
the PL photons emitted from the sample were collected by the same
objective lens and passed through a confocal pinhole (100 μm)
and a longpass filter (Semrock, LP02-442RU) to remove the excitation
laser. The photons were detected by an avalanche photodiode (APD)
single-photon counting module (PerkinElmer, SPCM-AQR-14). The signal
from the APD was connected to a time-correlated single-photon counting
PC board (Becker & Hickl, SPC630) to determine the PL lifetime.
The time resolution of the lifetime measurement (IRF) was approximately
0.3 ns. All measurements were performed at room temperature under
ambient conditions.
measured with picosecond-pulsed laser excitation at 405 nm (10.0 MHz,
90 ps full width at half-maximum) under an inverted confocal microscope
(Olympus, IX-71). The beam was reflected by a dichroic mirror (Semrock,
Di01-R405) and then focused to the sample in a quartz cuvette on a
sample stage by an objective lens (Olympus, 20×, NA 0.4), and
the PL photons emitted from the sample were collected by the same
objective lens and passed through a confocal pinhole (100 μm)
and a longpass filter (Semrock, LP02-442RU) to remove the excitation
laser. The photons were detected by an avalanche photodiode (APD)
single-photon counting module (PerkinElmer, SPCM-AQR-14). The signal
from the APD was connected to a time-correlated single-photon counting
PC board (Becker & Hickl, SPC630) to determine the PL lifetime.
The time resolution of the lifetime measurement (IRF) was approximately
0.3 ns. All measurements were performed at room temperature under
ambient conditions.