A multiple target chemosensor for the sequential fluorescence detection of Zn and S and the colorimetric detection of Fe in aqueous media and living cells

A novel multiple target sensor, ( E )-5-((4-(diethylamino)-2-hydroxybenzyldene)amino)-1 H -imidazole-4-carboxamide ( DHIC ), was synthesized for fluorescence detection of Zn 2+ and S 2− and colorimetric detection of Fe 3+/2+ in aqueous media. DHIC can operate as a turn "on-off" sequential fluorescent sensor for Zn 2+ and S 2− . Detection limits (1.59 μM and 8.03 μM) for Zn 2+ and S 2− are below the WHO standards (76.0 μM and 14.7 μM). The DHIC -Zn 2+ complex could be reversibly reused with ethylenediaminetetraacetic acid. Importantly, DHIC could image sequentially Zn 2+ and S 2− in living cells. Moreover, DHIC displayed a discriminatory color change from pale yellow to orange yellow to Fe 3+/2+ . The detection limit of DHIC for Fe 3+/2+ (0.73 μM and 1.11 μM) is far below the EPA drinking water standard (5.37 μM). The sensor DHIC could be applied to analyze Fe 3+ in real samples. A novel multiple target sensor DHIC was developed for the fluorescence detection of Zn 2+ and S 2− and colorimetric detection of Fe 3+/2+ . Moreover, DHIC could image sequentially Zn 2+ and S 2− in living cells.