Luminescent Sensor For Fe3 Research Articles

A new 8-connected Cd(II)-MOF as luminescent sensor for Fe3+

A new 8-connected Cd(II)-MOF as luminescent sensor for Fe3+

Synthesis of two new Cd(II)-MOFs based on different secondary building units with highly selective gas sorption for CO2/CH4 and luminescent sensor for Fe3+ and Cr2O72− ions

Two new metal-organic frameworks (MOFs), [Cd4(L1)2(H2O)4]·3(H2O)·DMA (1) and (Me2NH2)2[Cd2(L1)(L2)]·[solvent] (2) (DMA ​= ​N,N-Dimethylacetamide) were successfully synthesized via the solvothermal reaction procedure by a rigid V-shaped N-heterocyclic 2,6-di(2′,5′-dicarboxylatephenyl)pyridine (H4L1) ligand, terephthalic acid (H2L2) and Cd(II) ions in this work. Structural analyses show that the carboxylate groups of L14− adopt different coordination modes with Cd(II) ions in 1 and 2, which form the different secondary building units (SBUs) to yield two new different 3D MOFs. Compared with 1, the introduction of the terephthalic acid (H2L2) produces 2 with potential solvent area volume 51.9% (2608.5 ​Å3, per unit cell volume 5029.2 ​Å3). The gas sorption and luminescent experiments of 2 show the high selectivity of CO2 over CH4 and selective sensitivity for Fe3+ and Cr2O72− ions in aqueous solution. The experiment results offer a facile route for designing and yielding new potential multi-functional MOF materials in gas sorption and detecting Fe3+ and Cr2O72− ions.

One-pot synthesis of copper nanoconjugate materials as luminescent sensor for Fe3+ and I− detection in human urine sample

A simple synthetic approach of water-soluble and stable fluorescent copper nanoclusters (Cu NCs) at room temperature was proposed. The cysteamine functionalized nanoconjugate materials (CA-Cu NCs) exhibited variety of exceptional properties, including good water-solubility, photostability, low cytotoxicity and acting as an excellent cell imaging probe. Based on the electron transfer and aggregation induced fluorescence quenching mechanism, CA-Cu NCs were utilized in the selective determination of ferric (Fe3+) and iodide (I−) ions. The detection limits of Fe3+ and I− ions were calculated as 423 nM and 2.02 μM, which are lower than the maximum level of Fe3+ and I− ions, allowed in drinking water by the U.S. Environmental Protection Agency. The assay method of paper strip was also successfully applied for the detection of Fe3+ and I− ions in live cells and human urine.

In Situ Green Synthesis of Nitrogen-Doped Carbon-Dot-Based Room-Temperature Phosphorescent Materials for Visual Iron Ion Detection

Room-temperature phosphorescent (RTP) materials show great potential for ion detection due to a long lifetime and a high signal-to-noise ratio. Most RTP materials are limited to organometallic or organic compounds that are costly, toxic, and complex. Here, an in situ green synthesis of carbon dot (CD)-based RTP materials using Schisandra chinensis polysaccharide as the only carbon source, which has a natural nitrogen-containing structure for endogenous nitrogen-doping, is performed. RTP measurements show that the CD-based RTP materials had lifetimes up to 271.2 ms under 350 nm excitation and with a smaller energy gap (0.32 eV). In addition, they exhibit adequate quenching in the presence of iron ions (Fe3+). The visible RTP intensity is inversely proportional to the Fe3+ concentration over the range of 0.1–2 mM, with a 0.57 μM detection limit. Further, the prepared CD-based RTP materials have highly stable optical and physical properties, which open a new perspective as luminescent sensors for Fe3+ detection with inexpensive and green raw materials.

A stable anionic metal–organic framework with open coordinated sites: selective separation toward cationic dyes and sensing properties

A multifunctional anionic metal–organic framework was successfully synthesized using a new pyridyl–tricarboxylate ligand. It could be applied as a luminescent sensor for Fe3+ions and TNP and it showed selective adsorption of cationic dyes.

Two host-guest hybrids by encapsulation AlQ3 in zeolitic imidazolate framework-8 as luminescent sensors for Fe3+, CrO42- and acetone

In this work, zeolitic imidazolate framework-8 (ZIF-8), which possesses high porosity and excellent thermal and chemical stability, has been employed as host framework to encapsulate luminescent chromophores guest AlQ3 [tris(8-hydroxyquinoline)-aluminium]. Two host-guest hybrids AlQ3 @ZIF-8 (ZA-1 and ZA-2) were prepared by embedding different amounts of AlQ3 into the ZIF-8 cavities. As expected, the hybrids display intense luminescence with wide wavelength in the visible light region. The luminescent properties of ZA-1 and ZA-2 were developed to probe metal cations, anions and volatile organic molecules. Two hybrids exhibit high selective and sensitive quenching effects to Fe3+, CrO42- and acetone. More significantly, AlQ3 @ZIF-8 luminescent sensors are reusable for the trace detection.

A luminescent Zn(II)-based coordination polymer constructed by 5-((4-carboxyphenoxy)methyl)benzene-1,3-dioic acid and 4,4′-bipyridine for selective sensing of Fe3+

A novel coordination polymer [Zn(HL)(bpy)(H2O)] (1) has been prepared by utilizing π-conjugated aromatic ligand 5-((4-carboxyphenoxy)methyl)benzene-1,3-dioic acid (H3L) and rigid ligand 4,4′-bipyridine (bpy) under the hydrothermal condition. Compound 1 has been characterized by single crystal X-ray diffraction, power X-ray diffraction, elemental analysis, and thermogravimetric analysis. The structure of 1 exhibits 3D supermolecular structure with π–π interactions and hydrogen-bonding interactions. The solid state luminescent emission intensity of compound 1 is strong at room temperature. The rapid and efficient response of 1 to Fe3+ ion suggests that this material could be used as a luminescent sensor for Fe3+ ion.

Two 1D Looped Coordination Polymers as Luminescent Probes for Highly Selective Sensing of Fe3+ Ions

Two luminescent coordination polymers (LCPs), namely [CdL2]n (1) and [ZnL2]n (2) based on a new ligand 2-(2-methyl–benzimidazole-1-yl)-benzoic acid (HL), have been synthesized and characterized by single crystal X-ray diffraction, powder X-ray diffraction, infrared spectroscopy, elemental analysis, and thermogravimetric analysis. 1 and 2 exhibit similar 1D looped chains with different coordination modes of L. Both LCPs show strong fluorescent emission in the visible region. The fluorescence quenching response of 1 and 2 towards Fe3+ over other metal ions in DMF has been demonstrated by quenching titrations. Thus, 1 and 2 can be used as potential and highly selective luminescent sensors for Fe3+ ions.

Inside Cover: A Multi‐responsive Regenerable Europium–Organic Framework Luminescent Sensor for Fe3+, CrVI Anions, and Picric Acid (Chem. Eur. J. 52/2016)

Inside Cover: A Multi‐responsive Regenerable Europium–Organic Framework Luminescent Sensor for Fe³⁺, Cr^VI Anions, and Picric Acid (Chem. Eur. J. 52/2016)