An anthracene-based fluorescent sensor for sequential detection of zinc and copper ions

Sequential recognition of Zn^{2 +} and Cu^{2 +} by a new anthracene-containing dipyridylamine-based receptor 1 (N-((anthracen-9-yl) methyl)-N-(pyridin-2-yl)pyridin-2-amine) has been achieved. Receptor 1 exhibited highly selective and sensitive fluorescence "off-on" recognition property to Zn^{2 +} with a 1:1 binding stoichiometry. The resulting 1-Zn^{2 +} complex displayed high selectivity to Cu^{2 +} through the decrease in fluorescence intensity, demonstrating that 1-Zn ^{2 +} could detect Cu^{2 +} via metal displacement. The sequential recognition of Zn^{2 +} and Cu^{2 +} via metal exchange suggests that receptor 1 has a potential utility for Zn^{2 +} and Cu^{2 +} detection.