Supramolecular Chemistry Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
Supramolecular Chemistry Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
Spectrochim Acta A Mol Biomol Spectrosc. 2019 May 15;215:15-23. doi: 10.1016/j.saa.2019.02.052. Epub 2019 Feb 19.
Novel naked-eye cation-selective chemosensors were developed from derivatives of diaza-18-crown-6 bearing one or two azobenzenes functionalized with o-acetic acid or p-nitro groups. The chromogenic acid and nitro derivatives exhibited solvatochromic effects with a majority of quinone-hydrazone tautomer in DMSO. The study of sensing properties of all molecules towards several metal ions showed that the one and two nitro-bearing N1 and N2 derivatives responded selectively to Cr in MeCN with a color change from pink to colorless. They also showed selectivity for Hg in DMSO with a color change from purple to light yellow. The detection limit of N1 and N2 that render visual difference to the naked eye are 0.21 ppm and 0.31 ppm for Cr in MeCN, and 1.20 ppm and 1.00 ppm for Hg in DMSO, while that obtained from 3σ method are 0.08 ppm and 0.03 ppm for Hg in DMSO. These results demonstrate a potential use of p-nitro azobenzene diaza-18-crown-6 as naked-eye sensors, notably for Cr that brings acute toxic to aquatic life.
新型裸眼阳离子选择性化学传感器是由带有一个或两个偶氮苯官能团的二氮杂-18-冠-6 衍生物开发而成，这些偶氮苯官能团带有邻乙酸基或对硝基。显色酸和硝基衍生物在 DMSO 中表现出溶剂化效应，大部分醌腙互变异构体存在。对所有分子对几种金属离子的传感性能研究表明，带有一个和两个硝基的 N1 和 N2 衍生物在 MeCN 中对 Cr 选择性响应，颜色从粉红色变为无色。它们在 DMSO 中对 Hg 也表现出选择性，颜色从紫色变为浅黄色。N1 和 N2 的检测限为 0.21ppm 和 0.31ppm（在 MeCN 中对 Cr 的视觉差异）和 1.20ppm 和 1.00ppm（在 DMSO 中对 Hg 的视觉差异），而通过 3σ 方法获得的检测限为 0.08ppm 和 0.03ppm（在 DMSO 中对 Hg 的视觉差异）。这些结果表明，p-硝基偶氮苯二氮杂-18-冠-6 可用作裸眼传感器，特别是对水生生物具有急性毒性的 Cr。
