Fig. 1. The fluorescence spectra of the interaction of GQDs with trypsin

Fig. 2. The CD spectra of the interaction of GQDs with trypsin
c_Tryp=3.33×10^-6 mol·L^-1, [GQDs]:[Tryp]=0, 5, 10, 15, 20

Fig. 3. Three dimensional fluorescence spectra of the interaction of GQDs with trypsin
(a): c_Tryp=4.17×10^-6 mol·L^-1; (b): c_Tryp=4.17×10^-6 mol·L^-1; c_GQDs=4.17×10^-5 mol·L^-1

Fig. 4. The activity of Trypsin in the presence of GQDs
c_Tryp=4.17×10^-6 mol·L^-1, GQDs was added to this solution in the range of 0~8.33×10^-5 mol·L^-1 with an interval of 8.33×10^-6 mol·L^-1, the concentration of BAEE was 1.67×10^-4 mol·L^-1

Fig. 5. The UV-Vis spectra of the interaction of GQDs with trypsin
(a): (1→21): The concetration of Tryp was kept at 1.67×10^-5 mol·L^-1; GQDs was added to this solution in the range of 0~3.33×10^-4 mol·L^-1 with an interval of 1.67×10^-5 mol·L^-1; (b): (1→21): The concetration of GQDs was kept at 1.67×10^-5 mol·L^-1, Tryp was added to this solution in the range of 0~2.22×10^-6 mol·L^-1 with an interval of 1.11×10^-7mol·L^-1

Fig. 6. Recovered UV-Vis spectra (a) and concentration profiles (b) and (c)