A novel fluorescence sensor based on a porphyrinic zirconium-based metal–organic framework, L-cysteine-modified PCN-222 (L-Cys/PCN-222), was developed to selectively recognize histidine enantiomers and sensitively detect Hg²⁺. The dual-functional sensor was successfully prepared via the solvent-assisted ligand incorporation method and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), ¹H nuclear magnetic resonance (¹H NMR) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, circular dichroism (CD), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption–desorption analyses. L-Cys/PCN-222 not only showed a higher quenching response for L-histidine than that for D-histidine with a fast fluorescent response rate of <40 s but also exhibited low detection limits for L- and D-histidine (2.48 μmol L⁻¹ and 3.85 μmol L⁻¹, respectively). Moreover, L-Cys/PCN-222 was employed as a fluorescent and visual sensor for the highly sensitive detection of Hg²⁺ in the linear range of 10–500 μmol L⁻¹, and the detection limit was calculated to be 2.79 μmol L⁻¹ in surface water. The specific and selective recognition of chiral compounds and metal ions by our probe make it suitable for real field applications.

中文翻译：

---

用于组氨酸对映体和 Hg2+ 荧光传感的双功能卟啉锆基金属有机框架

开发了一种基于卟啉锆基金属有机框架的新型荧光传感器，L -半胱氨酸修饰的 PCN-222 ( L -Cys/PCN-222)，用于选择性识别组氨酸对映体并灵敏地检测 Hg ²⁺。通过溶剂辅助配体掺入法成功制备了双功能传感器，并利用 X 射线衍射（XRD）、扫描电子显微镜（SEM）、 ¹ H 核磁共振（¹ H NMR）光谱、傅里叶变换红外（ FT-IR）光谱、圆二色性（CD）、X射线光电子能谱（XPS）和氮气吸附-解吸分析。L -Cys/PCN-222 不仅对L - 组氨酸表现出比D - 组氨酸更高的猝灭响应，荧光响应速率<40 s，而且对L - 和D - 组氨酸表现出较低的检测限（2.48 μmol）分别为L ^-1和3.85 μmol L ^-1）。此外，采用L -Cys/PCN-222作为荧光和视觉传感器，在10~500 μmol L ^-1的线性范围内高灵敏度检测Hg ²⁺，计算出检测限为2.79 μmol L地表水中^-1 。我们的探针对手性化合物和金属离子的特异性和选择性识别使其适合实际现场应用。