A simple salicylaldehyde-bearing pyrazine as a turn-on fluorescent chemosensor for Al <sup>3+</sup> and Zn <sup>2+</sup> recognition and its applications
Yucun Liu, Miao Wu, Jihan Zhao, Yuan Wang, Yongling Zhang
Abstract
Abstract A simple fluorescent chemosensor, 5-(diethylamino)-2-((2-(pyrazin-2-yl) hydrazono)methyl)phenol, has been synthesized by Schiff-base condensation reaction. The chemosensor exhibited highly selective and sensitive “off-on” fluorescent responses toward Al 3+ and Zn 2+ but the signal of fluorescence emission varies. The detection limits were found to be 2.33 × 10 −7 M for Al 3+ and 1.68 × 10 −7 M for Zn 2+ , respectively. The binding mechanisms between chemosensor and Al 3+ or Zn 2+ ions were supported by Job′s, 1 H NMR, Fourier transform infrared spectra, and MS experiments. The sensing behavior was also studied with molecular logic functions of OR, AND, and NOT gates. In addition, the chemosensor was able to detect Al 3+ and Zn 2+ by producing distinct color changes observed by the naked eye on sensor-coated swabs. Moreover, the chemosensor was successfully applied to effectively detect Al 3+ and Zn 2+ in actual water and drug samples.