Fluorescent Zn-PDC/Tb³⁺ Coordination Polymer Nanostructure: A Candidate for Highly Selective Detections of Cefixime Antibiotic and Acetone in Aqueous System

Tb³⁺-doped zinc-based coordination polymer nanospindle bundles (Zn-PDC/Tb³⁺, or [Zn­(2,5-PDC)­(H₂O)₂]·H₂O/Tb³⁺) were synthesized by a simple solution precipitation route at room temperature, employing Zn­(NO₃)₂, Tb­(NO₃)₃, and 2,5-Na₂PDC as the initial reactants, and a mixture of water and ethanol with the volume ratio of 10:10 as the solvent. The as-obtained nanostructures presented strong fluorescent emission under the excitation of 298 nm light, which was attributed to the characteristic emission of the Tb³⁺ ion. It was found that the above-mentioned strong fluorescence of the nanostructures could be selectively quenched by cefixime (CFX) in aqueous solution. The other common antibiotics hardly interfered. Thus, as-obtained Zn-PDC/Tb³⁺ nanostructures could be prepared as a highly sensitive fluorescence probe for selective detection of CFX in an aqueous system. The corresponding detection limit reached 72 ppb. The theoretic calculation and UV–vis absorption experiments confirmed that the fluorescence quenching of Zn-PDC/Tb³⁺ nanostructures toward CFX should be attributed to the electron transfer and the fluorescence inner filter effect between the fluorescent matter and the analyte. In addition, the strong fluorescence of the nanostructures could also be selectively quenched by acetone in the water system

Flowerlike Copper(II)-Based Coordination Polymers Particles: Rapid Room-Temperature Fabrication, Influencing Factors, and Transformation toward CuO Microstructures with Good Catalytic Activity for the Reduction of 4‑Nitrophenol

A facile and environment-friendly approach for synthesis of flowerlike copper-based coordination polymer particles (CPPs) was reported. Copper acetate (CuAc₂) and sodium pyridine-2,3-dicarboxylate (2,3-Na₂PDC) were used as the initial reactants. The flowerlike Cu-PDC microstructures were obtained based on a simple direct precipitation between CuAc₂ and 2,3-Na₂PDC in a mixed solution of water and methanol with the volume ratio of 20:10 at room temperature. The as-obtained products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR), and elemental analysis. Some factors to affect the morphology and size of the Cu-PDC microstructures were systematically investigated such as the molar ratio of reactants, the volume ratio of water/methanol, acetic groups, and the reaction time. It was found that flowerlike Cu-PDC microstructures could be transformed into flowerlike CuO microstructures by heat-treating in air at 350 °C for 30 min. Experiments showed that the as-obtained flowerlike CuO microstructure exhibited a high catalytic activity for the reduction of 4-nitrophenol in excess NaBH₄ solution