A Ru(II) complex 1 ([Ru(bpy)₂(L)](PF₆)₂ (L = 2-(1H-pyrazol-5-yl)-1H-imidazo-[4,5-f] [1,10] phenanthroline, bpy = 2,2′-bipyridine)), which included adjacent imidazole and pyrazole moieties as responsive bidentate ligand, had been designed and synthesized as a ’turn-off’ fluorescent probe for sensitively and selectively detecting Cu²⁺ in methanol and test strips. It displayed easy synthesis, large Stokes shift (178 nm) and long emission wavelength (633 nm). After addition of Cu²⁺, the probe 1 exhibited obvious fluorescence quenching (ca. 83%) and color change from red to dark. The detection limit of Cu²⁺ ions was as low as 1.78 × 10⁻⁸ M, which was far lower than the permissible level of copper ion (∼20 μM) in drinking water set by the EPA (Environmental Protection Agency). Moreover, the results of test strip experiments and real water sample detection experiments demonstrated the probe 1 possesses potential application of ions recognition in environment.

Ru（II）配合物1（[Ru（bpy）₂（L）]（PF ₆）₂（L = 2-（1H-吡唑-5-基）-1H-咪唑-[4,5-f] [ 1,10]菲咯啉，bpy = 2,2'-联吡啶）），包括相邻的咪唑和吡唑部分作为响应性双齿配体，已被设计并合成为“关断”荧光探针，用于灵敏和选择性地检测Cu ^{2 +}在甲醇和试纸中。它显示出易于合成，大斯托克斯位移（178 nm）和长发射波长（633 nm）的特点。添加Cu ^2+后，探针1表现出明显的荧光猝灭（约83％），颜色从红色变为深色。Cu ²⁺离子的检出限低至1.78×10^-8  M，远低于EPA（环境保护署）设定的饮用水中允许的铜离子水平（〜20μM）。此外，试纸实验和实际水样检测实验的结果表明，探针1在环境中具有离子识别的潜在应用。