Copper ion (Cu) detection remains an important task for monitoring water quality because of its specific toxicity. Herein, a new dual-signal fluorescent probe was developed by combining zeolitic imidazolate framework-8 (ZIF-8) and lanthanide for the detection of Cu for the first time. The lanthanide coordination polymer (guanosine monophosphate and Eu, GMP/Eu) was initially incorporated into ZIF-8 to yield ZIF-8/GMP/Eu nanomaterials with extremely weak single emission fluorescence at 618 nm. It was found that the resulted nanomaterials could display a dual emission fluorescence at 515 nm and 618 nm after the introduction of tetracycline (TC) due to the synergistic effect of aggregation-induced emission effect (AIE, TC induced by ZIF-8) and antenna effect (AE, between TC and GMP/Eu). Interestingly, in the presence of Cu, the AIE of TC was destroyed because of the interaction of Cu with ZIF-8 and TC. The AE between TC and GMP/Eu disappeared due to the formation of complex between TC and Cu. A dual-signal fluorescent probe of ZIF-8/GMP/Eu/TC was thereby established for sensing Cu in the range of 0.5–100 μM. Such a dual-signal response strategy that intelligently utilized the “ON”/“OFF” of AIE and AE can not only eliminate the background interference, but also ensure the improved selectivity of Cu sensing. Subsequently, the dual-signal fluorimetric strategy was applied for the detection of Cu in environmental water samples, indicating the potential feasibility of applications for water quality monitoring.

中文翻译：

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沸石咪唑骨架8和镧系元素联合制备配位聚合物：基于聚集诱导发射和天线效应的协同效应用于传感Cu2+的双信号荧光探针

由于其特定的毒性，铜离子（Cu）检测仍然是水质监测的一项重要任务。在此，通过结合沸石咪唑酯框架-8（ZIF-8）和镧系元素，开发了一种新的双信号荧光探针，首次用于检测铜。最初将镧系配位聚合物（鸟苷单磷酸和Eu，GMP/Eu）掺入ZIF-8中，得到在618 nm处具有极弱单发射荧光的ZIF-8/GMP/Eu纳米材料。结果发现，由于聚集诱导发射效应（AIE，ZIF-8诱导的TC）和天线的协同作用，引入四环素（TC）后，所得纳米材料可以在515 nm和618 nm处显示出双发射荧光效应（AE，介于 TC 和 GMP/Eu 之间）。有趣的是，在 Cu 存在的情况下，由于 Cu 与 ZIF-8 和 TC 的相互作用，TC 的 AIE 被破坏。由于TC和Cu之间形成络合物，TC和GMP/Eu之间的AE消失。由此建立了 ZIF-8/GMP/Eu/TC 双信号荧光探针，用于检测 0.5–100 μM 范围内的 Cu。这种智能利用AIE和AE的“ON”/“OFF”的双信号响应策略不仅可以消除背景干扰，还可以确保Cu传感的选择性得到提高。随后，双信号荧光策略被应用于环境水样中铜的检测，表明其应用于水质监测的潜在可行性。