Emission spectra and fluorescence decay curves of the PCP complexes. (a) Emission spectra of the PCP complexes deposited on (red) and off (black) silica nanoparticles. (b) Fluorescence decay curves of PCP deposited on (red) and off (black) silica nanoparticles. The excitation wavelength for both experiments was 480 nm. The transients are normalized, and the one measured for the PCP complexes off the silica nanoparticles was shifted vertically (multiplied by 10) for clarity.