Two-dimensional layered lanthanide diphosphonates: synthesis, structures and sensing properties toward Fe³⁺ and Cr₂O₇²⁻

Abstract

Four new lanthanide phosphonates with two-dimensional layered crystal structures have been synthesized and investigated for the optical sensing of Fe3+ and Cr2O72− ions.

Dual-Functional Metal–Organic Framework for Luminescent Detection of Carcinoid Biomarkers and High Proton Conduction

“…The asymmetric unit of 1 includes one Tb III ion, two half H 2 L 2– anions, one H 2 bts – anion, one aqua ligand, and one lattice water molecule (Figure a). The Tb–O bond lengths vary from 2.225(3) to 2.468(3) Å (Table S2), which are in accord with those in other lanthanide-based phosphonates. − The Tb III ion adopts a seven-coordinated mode with the geometry of a capped octahedron that was analyzed by Shape software. Five of the seven coordination sites for the Tb1 ion are filled by five phosphonate oxygen atoms (O2A, O3, O4, O4B, and O5) from three phosphonate ligands.…”

“…The curve can be well fitted to I 0 / I = 2.382 exp­(9.922­[C]) – 0.624 for HT and I 0 / I = 2.873 exp­(10.302­[C]) – 1.543 for HIAA. Such a phenomenon indicates that the quenching process caused by HT and HIAA can result from self-absorption or energy transfer processes at higher concentrations. ,,, The detection limits (LODs) of 1 for HT and HIAA are calculated to be 3.33 and 6.30 nM, respectively (Figure S12), according to the equation 3σ/ k , (σ represents the standard deviation obtained by 10 repeated luminescent measurements of blank solutions, and k represents the slope of the luminescent intensities vs the concentrations of the analytes at low concentrations). It can be noted that the LODs are obviously lower than those of the reported three MOFs sensors and are comparable to those of the traditional analysis methods such as LC-MS, ED, HPLC-LD, and so on (Table S4).…”

Fabrication of a Terbium-Functionalized Cadmium Organic Framework with Proper Energy Levels as a Ratiometric Probe of an Anthrax Biomarker

“…Metal–organic frameworks (MOFs) are a class of crystalline material assembled from metal ions and organic ligands, characterized by a porous crystal structure, a large surface area, and high adjustability, − showing great potential applications in the fields of gas adsorption, fluorescence sensors, supercapacitors, and catalysis. − Luminescent MOFs, involving d- (mainly Zn 2+ , Cd 2+ ) and f-containing (mainly Eu 3+ and Tb 3+ ) MOF materials, have been applied in the fluorescent sensing of metal ions, food safety, explosives, and so on. − Recently, MOF materials have been successfully used for the fluorescence sensing of DPA . It is worth mentioning that Tb­(III)-based luminescent MOFs are particularly feasible for the detection of bacterial spores because of the strong interaction and the suitable energy levels of DPA and Tb­(III) ions. − For instance, a Tb-MOF based on a steric carboxylate ligand can effectively sensitize DPA based on luminescence recovery mode with the LOD down to 7.8 μM and exhibits obvious luminescence color change from blue to blue-green .…”

Luminescent MOFs for selective sensing of Ag+ and other ions (Fe(iii) and Cr(vi)) in aqueous solution

“…In recent years, fluorescence sensing has been widely concerned in the detection of toxic pollutants such as inorganic heavy metal ions, toxic anions and small organic molecules, [10][11][12][13][14] because of its high operability, low cost and excellent response performance. [15][16][17][18] Metal-organic frameworks (MOFs) are porous crystalline materials formed by self-assembly of organic ligands and metal cations or metal clusters through coordination bonds. [19][20][21][22][23][24] Due to their diverse properties and highly tunable structure, [25][26][27] they have potential applications in the fields of gas storage/ separation, [28][29][30] magnetic applications, 31,32 luminescence, 33,34 catalysis, 35,36 and drug delivery.…”