137279.fig.002
Figure 2: Fluorescence spectra of (A, B) GFX (500 ng/mL) in acetate buffer, pH 5.5/SDS system; (A′, B′) GFX (500 ng/mL) in acetate buffer, pH 3.5, where (A, A′) are the excitation spectra and (B, B′) are the emission spectra.