The fluorescent sensor XQN for Zn2+ based on rhodamine-6G have been designed and synthesized. XQN showed fluorescent specific selectivity and high sensitivity for Zn2+ against other metal ions such as Fe3+, Cr3+, Hg2+, Ag+, Ca2+, Cu2+, Pb2+, Cd2+, Ni2+, Co2+ and Mg2+ in CH3CN-PBS(phosphate buffer saline) (10 mM, v/v=7:3, pH = 7.4) solution. The distinct color change and the rapid emergence of fluorescence emission provided naked-eyes detection for Zn2+. The test strip results showed that these sensors could act as a convenient and efficient Zn2+ test kit. The recognition mechanism of the sensor toward Zn2+ was evaluated by IR and the Job’s plots. The detection limits of XQN towards Zn2+ was calculated as 2.39 µM. In addition, XQN-Zn2+ fluorescence lifetime and fluorescence quantum yield were also measured.

Rui Qiao, Hai-Yun Fan, Cui-Bing Bai, Ling Dai, Lin Zhang, Jie Zhang, Shui-Sheng Chen and Hui Miao