| Coordination polymer crystal materials have the characteristics of high specific surface area,modifiable ligands and flexible framework structure.Thus,it can be widely used in the fields of adsorption and fluorescence detection of environmental pollutants.However,due to the limited performance of a single coordination polymer material,it cannot be fully expanded to practical applications.The development and application of composite materials based on coordination polymers have greatly solved the limitation.It meets the needs of practical applications and provides more advanced technologies and methods for pollutant adsorption and fluorescence detection.In this paper,10 new copper/silver coordination polymers were synthesized b y selecting aromatic tricarboxylic acid ligands,nitrogen-containing aromatic dicarboxylic acid ligands,rigid nitrogen heterocyclic lig ands and flexible nitrogen heterocyclic ligands through crystal engineering theory.According to the detection and adsorption requirements,functionalized composite materials were prepared.The structure,adsorption and fluorescence detection performance o f copper/silver coordination polymers were studied,and the infl uence of host-guest interaction on adsorption and fluorescence detection performance were clarified.At the same time,we deeply explored the preparation method of copper/silver coordination polymer matrix composites and their application value in adsorption and fluorescence detection.In this paper,we selected 3,5-bis（4-carboxybenzyloxy）benzoic acid（H3bcob）as the organic ligand to construct a porous coordination polymer[Cu2IIbcob（OH–）]n（1）.Using the opened metal site of the central metal Cu2+,the carbon quantum dots（Rh B-CDs）modified with Rhodamine B（Rh B）were intervened into the coordination polymer 1 to prepare dual emission fluorescent probes（Rh B-CDs@1）.Rh B-CDs@1 combined the porosity and self-alignment function of coordination polymer 1 with different fluorescence responses to different classes of antibiotics.Among them,the ratiometric fluorescence detection of quinolone antibiotics was realized,and the detection limits of ciprofloxacin（CPFX）:0.08μM,norfloxacin（NFX）:0.14μM.Meanwhile,The fluorescence quenching detection of nitrofuran antibiotics was performed,and the detection limits of nitrofurantoin（NFT）:0.31μM and nitrofuran（NZF）:0.33μM,respectively.Nitrogen-containing sites and functional groups were introduced on the basis of aromatic tricarboxylic acid ligands.We selected 2,5-bis（3-carboxyphenyl）-1,3,4-oxadiazole（H2cboa）,3,3’-（4-amino-1,2,4-triazole）-3,5-benzoic acid（H2adta）to construct two divalent copper coordination polymers{[Cu5II（cboa）4（CH3CN）4Cl]?3CH3CN}n（2）and{[CuII（adta）（H2O）]?DMF?H2O}n（3）.Coordination polymer 3 has amino sites facing one-dimensional channel,which can be used as reactive groups to introduce the luminescent molecule 9-anthraaldehyde（9A）.And the hydrogel network with dual emission centers was prepared based on sodium alginate.The hydrogel material has high-selectivity and sensitivity fluorescence detection performance for flumequine,which the detection limit reaches 48 n M.Simultaneously,it exhibits good stability,easy recycling and visualization function,which greatly expands the practical application of coordination polymer materials.The rigid nitrogen heterocyclic organic ligand 5-（4-（1H-1,2,4-triazolyl）phenyl）-2H-tetrazole（Htpt）was selected.Two copper coordinat ion polymers[CuI（tpt）]n（4）and{[CuII（tpt）2]?2H2O}n（5）with different central metal valences were constructed.The central copper valence state of coord ination polymer 4 is monovalent,and it exhibits typical MLCT-characterized fluorescence emission with a maximum emission wavelength at 540 nm.The central copper valence state of coordination polymer 5 is divalent,which has typical d→d transition quenching characteristics,but 5 has a higher specific surface area.Based on the analysis of structure and properties,coordination polymers 4 and 5 constructed from the same ligands can be fabricated by elect rodeposition and liquid phase epitaxy methods.The assembly of crystal layers with different functions was realized by the surface"one-to-one"coordination bond,and the 5-on-4heterostructure film based on foamed cop per was prepared.The film can realize the detection and adsorption of Cr2O72-(LOD=2.16?10-6 g?L-1,qmax=203.25mg?g-1).The 5-on-4 film adsorbed on Cr2O72-can realize the fluorescence“turn on”sensing of p-aminophenarsine acid（p-ASA）with the detection limit of 5.56?10-8 g?L-1.The rigid nitrogen heterocyclic ligands 1-（4-（tetrazole-5-yl））3-（pyridyloxazin-2-yl）pyrazole（Htpp）with more nitrogen-containing sites and greater degree of conjugation were selected.A monovalent copper coordination polymer[CuI（tpp）]n（6）with a 2D layered structure was constructed.The synthesized coordination polymer 6 emits orange-red fluorescence with a maximum emission wavelength at 655 nm.Coordination polymer 6 has a large number of uncoordinated nitrogen atoms,which can serve as a template for self-assembly to grow ZIF-8 porous frameworks on its surface by a heteroepitaxial strategy.The ZIF–8–on–6 heterostructure achieves synergistic adsorption and fluorescence sensing properties for p-ASA in aqueous system(LOD=4?10-7g?L-1,qmax=303.0 mg?g-1).Among them,the ZIF-8 layer as the adsorption layer,based on the synergistic effect of hydrogen bonds,coordination bonds andπ???πstacking,ZIF–8–on–6 possesses excellent p-ASA adsorption capacity.At the same time,due to the molecular sieve effect and pre-concentration effect of ZIF-8,it possesses extremely high detection selectivity and sensitivity for p-ASA.We chose flexible nitrogen heterocyclic ligands 1-（triazol-1-yl）-4-（（tetrazol-5-yl）methyl）benzene（Htrb）,1-（tetrazol-5-yl）-4-（（Triazol-1-yl）methyl）benzene（Hteb）to synthesis three flexible silver based coordination polymers[Ag（trb）]n（8）,[Ag2（trb）2?DMF]n（9）and[Ag（teb）]n（10）.Coordination polymers 8–10 have fluorescence emission typical of LLCT characteristics.Among them,CH3SH can reduce the charge transfer from ligand to ligand through hydrogen bonding,coordination interaction.And an efficient fluorescence quenching effect was produced on the coordination polymer 10 at low concentrations（the quenching efficiency reach ed 99%）.The 10@PVDF membrane was prepared by a mixed matrix strategy.Based on charge transfer,a high-sensitivity detection of CH3SH visible to the naked eye is achieved with a detection limit of 0.48μM. |
