Figure 3
From: An activatable NIR turn-on fluorescent probe for copper (II) ion and live cell imaging

Fluorescence titration of MB-M (10 μM) with Cu2+ ions (0–6 equiv.) in 4:6 (v/v) MeCN-Tris. HCl buffer (10 mM), pH 7.4. The excitation and emission slits are 5 nm and λex = 620 nm.