Fig. 1. Three-dimensional fluorescence spectra of (a) Pyrene, (b) 1-Hydroxypyrene, (c) 1-Aminopyrene, (d) 1-Methylpyrene, (e) 1-Pyrenecarboxylic acid and (f) 1-Bromopyrene under different pH conditions

Fig. 2. The relative fluorescence intensity of PAHs under different pH conditions

Fig. 3. The complex structure of (a) 1-Hydroxypyrene, (b) 1-Aminopyrene and (c) 1-Pyrenecarboxylic acid with water