Three novel fluorescent probes (L1, L2 and L3) derived from 2-hydroxyphenyl-4-chloromethyloxazole 8-ydroxyquinaldine were designed and synthesized. The probes showed highly selectively and sensitivity towards Cu²⁺ ion through “turn off” response in DMF/H₂O solution (v/v = 1/1, 0.01 M, Tris-HCl buffer, pH 7.30). The detection limits of probes were up to 8.24 × 10⁻⁸ M for Cu²⁺ ion, which were much lower than drinking water permission concentrations by the United States Environmental Protection Agency. Sequentially, the L1-Cu²⁺, L2-Cu²⁺ and L3-Cu²⁺ complexes detected citrate anion (CA) through “turn on” response. The probes, were also found to be reversible and recyclable toward Cu²⁺ ion and CA controlled “On–Off–On” fluorescent switch and acted as molecular logic gates. Furthermore, the in vivo sensitivity experiments of Cu²⁺ ion and CA were demonstrated through fluorescence imaging in living cells.

设计并合成了衍生自2-羟基苯基-4-氯甲基恶唑8-羟基喹哪啶的三种新型荧光探针（L1，L2和L3）。通过在DMF / H ₂ O溶液（v / v = 1 / 1，0.01 M，Tris-HCl缓冲液，pH 7.30）中的“关闭”响应，探针显示出高度选择性和对Cu ²⁺离子的敏感性。 Cu ²⁺离子的探针检出限高达8.24×10 ^-8 M ，远低于美国环境保护局的饮用水许可浓度。依次为L1-Cu 2 ⁺，L2-Cu ²⁺和L3-Cu ²⁺络合物通过“开启”响应检测到柠檬酸根阴离子（CA）。还发现这些探针可逆和可回收，可用于Cu ²⁺离子和CA控制的“ On-Off-On”荧光开关，并充当分子逻辑门。此外，通过荧光成像在活细胞中证明了Cu ²⁺离子和CA的体内敏感性实验。