A water‐applicable hexamethylbenzene (HMB) chemosensor, (E)‐2‐((2‐hydroxy‐3‐methoxybenzylidene)amino)benzamide, displayed a selective colour change from colourless to yellow in the existence of copper ions. The detection limit was computed as 1.57 μmol/L, which is substantially lower than the World Health Organisation guideline (31.5 μmol/L) for copper ions. Probe HMB could also sense and quantify copper ions in real water samples. The coordination mode of HMB to copper ions was demonstrated through Job plot, electrospray ionisation mass spectroscopy and proton nuclear magnetic resonance titration, and was also supported by theoretical studies.

中文翻译：

---

用于选择性检测铜离子的比色化学传感器

水溶性六甲基苯（HMB）化学传感器（E）-2-（（2-羟基-3-甲氧基亚苄基）氨基）苯甲酰胺在存在铜离子的情况下显示出从无色到黄色的选择性颜色变化。计算出的检出限为1.57μmol/ L，大大低于世界卫生组织对铜离子的指导标准（31.5μmol/ L）。HMB探针还可以检测和量化真实水样中的铜离子。通过Job图，电喷雾电离质谱和质子核磁共振滴定法证明了HMB与铜离子的配位模式，并得到了理论研究的支持。