Figure 3.

(A) Schematic representation of the ratiometric change of fluorescence intensities at 530 nm after excitation at 485 nm and 510 nm (Fluorescence ratio I₄₈₅/I₅₁₀) for conjugates 11–15 incubated in HEPES buffer and measured at 0 h (black columns), HEPES buffer without GSH for 3 h (red columns) and in HEPES buffer with GSH (5 mm) for 3 h at 37 °C (blue columns). (B) Time monitored cleavage of conjugate 13 in medium without GSH (black), after treatment of the HeLa cells (red) or HeLa cells pretreated by 20 mm GSH (blue) with conjugate 13. (C) The microscopy images of the internalization of conjugate 13 inside the HeLa cells before treatment and (D) 2 h after treatment with GSH (20 mm).