Fig. 1. TEM images of the CDs

Fig. 2. Viabilities of hepatocytes incubated with different concentrations of CDs by MTT assayin mice

Fig. 3. (a) UV-Vis spectra and Fluorescence spectra of CDs; (b) Fluorescence spectra under different excitation wavelengths
Conditions: 180 ℃, 16 h, λ_ex=532 nm, λ_em=596 nm, concentration of CDs: 20 μg·mL^-1

Fig. 4. FTIR spectra of CDs

Fig. 5. (a) Fluorescent intensities variations of CDs added in differentmetal ions; (b) A plot of the fluorescence intensity against Hg²⁺ concentration in a range of 0~10 μg·mL^-1
Insert shows the linear relationship between the relative fluorescence intensity [(F₀-F₁)/F₀] and Hg²⁺ concentration (0~0.005 μg·mL^-1)