Fig. 2. (a) The fluorescent spectra changes of ICTAD-1 (10 μM) in DMF under the irradiation of daylight lamp for 120 min; (b) the fluorescent spectra of ICTAD-1 (10 μM) in different pH aqueous solutions (1% DMF); (c) the linear relationship between the polarity of solvent and the maximum emission wavelength; (d) the fluorescence spectra of ICTAD-1 (10 μM) in solvents of different viscosity, EG: ethylene glycol.