Figure 6.

(A) Fluorescence emission spectra of CQDs in the presence of different concentrations of Hg²⁺. (B) The plot of I/I₀ versus the concentration of Hg²⁺, the inset is the linear section of the plot (performed in pH 5.0, 50 mM NaAc-HAc buffer; I₀ and I correspond to the fluorescence intensity of CQDs at 415 nm in the absence and presence of tap water, respectively; excitation wavelength is 330 nm).