A Water-Stable Luminescent ZnII Metal-Organic Framework as Chemosensor for High-Efficiency Detection of CrVI -Anions (Cr2 O72- and CrO42- ) in Aqueous Solution

Insight into the formation of H-bonds propagating the monomeric zinc complexes of a tridentate reduced Schiff base to form an infinite chain

The formation of an infinite 1D assembly is governed by the H-bonding interactions in the solid state structure of the two zinc complexes. It has been analyzed energetically using DFT calculations and several computational tools.

Carbazole-conjugated-coumarin by enone realizing ratiometric and colorimetric detection of hypochlorite ions and its application in plants and animals

Detection of hypochlorite ions (ClO^-) in the organisms is of great significance for finding effective treatments for inflammations and diseases. Recently, fluorescent probes have aroused wide public concern as one of the effective tools for detecting molecules and ions. Nevertheless, due to low sensitivity and poor biocompatibility, the effect of fluorescent probes for biological imaging is still not ideal. For this, we developed a novel ratiometric fluorescent probe, 7-(diethylamino)-3-((E)-3-(9-ethyl-9H-carbazol-3-yl)acryloyl)-2H-chromen-2-one (DCC), which could be used for colorimetric detection of ClO^-. Study showed that, the detection mechanism of DCC is that probe can be rapidly oxidized to an enoic acid by ClO^-, resulting in a series of changes in spectral properties. This mechanism was confirmed experimentally and verified by theoretical calculations. It is worth mentioning that DCC has not only been successfully applied to the detection of exogenous and endogenous OCl^- in living cells, but also used for the detection of ClO^- in zebrafish, and Arabidopsis.

A luminescent Cd(II)-metal organic frameworks combined of TPT and H3BTC detecting 2,4,6-trinitrophenol and chromate anions in aqueous

A new luminescence Cd(II)-MOF (1) ([Cd₃(BTC)₂(TPT)(H₂O)₂]·4H₂O, TPT = tris(4-pyridyl)triazine, H₃BTC = 1,3,5-benzenetricarboxylic acid) was successfully synthesized under solvothermal conditions. 1 contains 3D framework which consist of Cd atoms and btc^3- anions with the large channels along c axis. Then, tpt ligands locate in the channels by utilizing three N atoms to bridge two Cd1 atoms and one Cd2 atom. 1 not only possesses remarkable thermal stability, but also can steadily exist in different organic solvents and various acid/base solutions (pH = 3-12). Moreover, 1 can detect 2,4,6-trinitrophenol (TNP) and chromate (CrO₄^2-/Cr₂O₇^2-) anions with high selectivity and sensitivity in water via the luminescent quenching. The detection limits of 1 for TNP and CrO₄^2-/Cr₂O₇^2- are 6.23 μM and 2.13 μM/2.87 μM. The mechanism of TNP luminescence quenching may be attributed to photoinduced electron transfer and resonance energy transfer, and CrO₄^2-/Cr₂O₇^2- quenching involves resonance energy transfer and competitive absorption of light. Additionally, 1 has the great anti-interference ability and repeatability for detecting TNP and CrO₄^2-/Cr₂O₇^2-, which can display the feasibility of this material as a stable luminescent probe in aqueous system.

Water and Metal-Organic Frameworks: From Interaction toward Utilization

The steep stepwise uptake of water vapor and easy release at low relative pressures and moderate temperatures together with high working capacities make metal-organic frameworks (MOFs) attractive, promising materials for energy efficient applications in adsorption devices for humidity control (evaporation and condensation processes) and heat reallocation (heating and cooling) by utilizing water as benign sorptive and low-grade renewable or waste heat. Emerging MOF-based process applications covered are desiccation, heat pumps/chillers, water harvesting, air conditioning, and desalination. Governing parameters of the intrinsic sorption properties and stability under humid conditions and cyclic operation are identified. Transport of mass and heat in MOF structures, at least as important, is still an underexposed topic. Essential engineering elements of operation and implementation are presented. An update on stability of MOFs in water vapor and liquid systems is provided, and a suite of 18 MOFs are identified for selective use in heat pumps and chillers, while several can be used for air conditioning, water harvesting, and desalination. Most applications with MOFs are still in an exploratory state. An outlook is given for further R&D to realize these applications, providing essential kinetic parameters, performing smart engineering in the design of systems, and conceptual process designs to benchmark them against existing technologies. A concerted effort bridging chemistry, materials science, and engineering is required.

Rational synthesis of an ultra-stable Zn(ii) coordination polymer based on a new tripodal pyrazole ligand for the highly sensitive and selective detection of Fe3+ and Cr2O72- in aqueous media

A mixed-ligand strategy has been used to construct stable luminescent coordination polymers (CPs). An ultra-stable Zn(ii) coordination polymer, [Zn(H3tpb)(Hbtc)]n (1) was hydrothermally synthesized by employing a new tripodal pyrazole ligand H3tpb and a classical carboxylic ligand H3btc (H3tpb = 1,3,5-tris(pyrazolyl)benzene, H3btc = 1,3,5-benzenetricarboxylic acid). Complex 1 exhibits a 2D sql network. Importantly, 1 not only possesses excellent thermal stability but also shows superior chemical stability in terms of water resistance, acid/base aqueous solutions tolerance (pH = 2-12), and organic solvents resistance. This excellent structural stability was further illustrated from the perspective of thermal decomposition kinetics. The luminescence properties were investigated, showing that complex 1 displays high sensitivity and selectivity for detecting Fe3+ and Cr2O72- ions in aqueous solutions via luminescence quenching effects.

Ultrasensitive detection of Cr(VI) (Cr2O72-/CrO42-) ions in water environment with a fluorescent sensor based on metal-organic frameworks combined with sulfur quantum dots

Accurate, simple and quick detection methods for Cr(VI) detection are urgently needed for water quality monitoring. Herein, a novel and facile method of detecting Cr(VI) (Cr₂O₇^2-/CrO₄^2-) ions is developed via the fluorescent detection technology based on metal-organic frameworks (MOFs) doped with sulfur quantum dots (SQDs) (SQDs@UiO-66-NH₂). The blue-light-emitting SQDs@UiO-66-NH₂ composites exhibit excellent fluorescent properties in water environment with high quantum yield (68%) and ideal fluorescent stability, thus demonstrating excellent potential for serving as a chemical sensor. After characterizing the performance and stability of SQDs@UiO-66-NH₂, qualitative and quantitative detection of Cr₂O₇^2- and CrO₄^2- ions was successfully conducted. The fluorescence of SQDs@UiO-66-NH₂ composites in aqueous solution was quenched effectively with more than 90% quenching efficiency by Cr(VI) via the inner filter effect. The detection system provides considerable advantages such as rapid response (10 s), high sensitivity with a low detection limit of 0.16 μM in a broad linear range of 0-200 μM (R² = 0.99) for Cr₂O₇^2- and 0.17 μM for CrO₄^2- in a broad linear range of 0-220 μM (R² = 0.99), high selectivity and reproducibility for at least five cycles with simple washing with alcohol. In practical applications, the sensor showed rapid response, high sensitivity and excellent recoveries (96.7%-105.4%) for detecting Cr₂O₇^2- in real water samples. Furthermore, a SQDs@UiO-66-NH₂-based fluorescent test paper was successfully developed, providing a simple, reliable and portable method for Cr(VI) (Cr₂O₇^2-/CrO₄^2-) detection in water environment.

2D Nanoarchitectonics: Soft Interfacial Media as Playgrounds for Microobjects, Molecular Machines, and Living Cells

Soft and flexible two-dimensional (2D) systems, such as liquid interfaces, would have much more potentials in dynamic regulation on nano-macro connected functions. In this Minireview article, we focus especially on dynamic motional functions at liquid dynamic interfaces as 2D material systems. Several recent examples are selected to be explained for overviewing features and importance of dynamic soft interfaces in a wide range of action systems. The exemplified research systems are mainly classified into three categories: (i) control of microobjects with motional regulations; (ii) control of molecular machines with functions of target discrimination and optical outputs; (iii) control of living cells including molecular machine functions at cell membranes and cell/biomolecular behaviors at liquid interface. Sciences on soft 2D media with motional freedom and their nanoarchitectonics constructions will have increased importance in future technology in addition to popular rigid solid 2D materials.

Application of Various Metal-Organic Frameworks (MOFs) as Catalysts for Air and Water Pollution Environmental Remediation

The use of metal-organic frameworks (MOFs) to solve problems, like environmental pollution, disease, and toxicity, has received more attention and led to the rapid development of nanotechnology. In this review, we discuss the basis of the metal-organic framework as well as its application by suggesting an alternative of the present problem as catalysts. In the case of filtration, we have developed a method for preparing the membrane by electrospinning while using an eco-friendly polymer. The MOFs were usable in the environmental part of catalytic activity and may provide a great material as a catalyst to other areas in the near future.

Zinc(ii)-based coordination polymer encapsulated Tb3+ as a multi-responsive luminescent sensor for Ru3+, Fe3+, CrO4 2-, Cr2O7 2- and MnO4. RSC Adv 2020;10:6022-6029. [PMID: 35497449 PMCID: PMC9049217 DOI: 10.1039/c9ra09541a]

A zinc(ii)-based coordination polymer (CP), namely [Zn(modbc)2] n (Zn-CP) (modbc = 2-methyl-6-oxygen-1,6-dihydro-3,4'-bipyridine-5-carbonitrile), has been synthesized and characterized. Single-crystal structural determination reveals that Zn-CP is a two-dimensional framework structure with tetranuclear homometallic Zn4(modbc)4 units cross-linked by modbc. The excellent luminescence as well as good stability of Zn-CP do not enable it to have selective sensing capability for different ions. After encapsulation of Tb3+ in Zn-CP, the as-obtained fluorescent functionalized Tb3+@Zn-CP maintained excellent luminescence as well as stability, which made it a highly selective and sensitive multiresponsive luminescent sensor for Ru3+, Fe3+, CrO4 2-, Cr2O7 2-, and MnO4 - with high sensitivity, good anti-interference performance, and quick response time (∼10 s). The detection limits are 0.27 μM, 0.57 μM, 0.10 μM, 0.43 μM and 0.15 μM, respectively. A possible sensing mechanism was discussed in detail.

Various Cd(ii) coordination polymers induced by carboxylates: multi-functional detection of Fe3+, anions, aspartic acids and bovine serum albumin

By adjusting carboxylates, six Cd(ii) coordination polymers based on a naphthalene-methylene mixed-bridged-amide ligand, [Cd(L)(DNBA)2] (1), [Cd2(L)2(BDC)2(H2O)2]·2H2O (2), [Cd(L)(1,4-CHDA)] (3), [Cd(L)(HIPA)(H2O)]·H2O (4), [Cd(L)(MIP)]·H2O (5), and [Cd(L)(PMA)0.5(H2O)]·H2O (6) [L = N,N'-bis(4-methylenepyridin-4-yl)-1,4-naphthalene dicarboxamide, HDNBA = 3,5-dinitrobenzoic acid, H2BDC = 1,4-benzenedicarboxylic acid, 1,4-H2CHDA = 1,4-cyclohexanedicarboxylic acid, H2HIPA = 5-hydroxyisophthalic acid, H2MIP = 5-methylisophthalic acid and H4PMA = pyromellitic acid] have been synthesized under hydrothermal conditions. 1 shows a 4-c sql coplanar structure. 2 exhibits a 2-fold vertical interpenetrating structure based on wave-like 4-c sql layers. 3 shows a (3,5)-c pnh network containing a unique μ3-L. 4 features a 4-c sql wave-like network. 5 and 6 exhibit 3D structures with 6-c pcu and 4-c mog topologies. The number of carboxyl groups and functional group positions of the carboxylates have an important influence on the structures of the title complexes. The fluorescent responses of 1-6 towards Fe3+, anions, aspartic acid and bovine serum albumin were investigated. Among them, 4 shows sensitivity and selectivity (KSV = 1.16 × 104 L mol-1 for Fe3+, 1.03 × 104 L mol-1 for CrO42-, 1.08 × 104 L mol-1 for Cr2O72-, 1.17 × 104 L mol-1 for MnO4- and 1.05 × 104 L mol-1 for aspartic acid).

Structural diversity, magnetic properties, and luminescence sensing based Ni(ii)/Zn(ii) coordination polymers of the semirigid 3,3′-((5-carboxy-1,3-phenylene)bis(oxy))dibenzate ligand

Four novel CPs were synthesized and two Zn(ii)-CPs can be used as fluorescent probes for the detection of CrO₄²⁻/Cr₂O₇²⁻.

Grafting functional groups in metal–organic frameworks for U(vi) sorption from aqueous solutions

Recent highlights of the organic groups-functionalized MOFs for uranium extraction from aqueous solution are discussed.

Five naphthalene-amide-bridged Ni(ii) complexes: electrochemistry, bifunctional fluorescence responses, removal of contaminants and optimization by CVD

Five multifunctional Ni-CPs based on a new naphthalene-amide and different carboxylates were obtained and exhibited various properties. CNTs were synthesized from the precursors of CPs, showing selective removal of contaminants in water.

Electron transfer in the confined environments of metal–organic coordination supramolecular systems

In this review, we overview regulatory factors and diverse applications of electron transfer in confined environments of supramolecular host–guest systems.

Hydrothermal synthesis of two 2D uranyl coordination polymers: structure, luminescence, and photocatalytic degradation of rhodamine B

Two hydrothermal synthesized uranyl-organic coordination polymers showing effective photocatalytic activities for RhB degradation with quick equilibrium time in water.

Two isostructural Ln3+-based heterometallic MOFs for the detection of nitro-aromatics and Cr2O72−

In/Eu-CBDA and In/Tb-CBDA can be used as potential chemical sensors for application in the detection of nitro-aromatics and Cr₂O₇²⁻.

Water-stable LnIII-based coordination polymers displaying slow magnetic relaxation and luminescence sensing properties

Six Ln-CPs were synthesized: Dy-CP shows slow magnetic relaxation, and Eu-CP and Tb-CP exhibit recyclable and multi-responsive sensing for Fe³⁺, MnO₄⁻, Cr^VI-anions (CrO₄²⁻, Cr₂O₇²⁻) and TNP in an aqueous system.

Integration of Cd:ZnS QDs into ZIF-8 for enhanced selectivity toward Cu2+ detection

Cd:ZnS QDs were integrated into ZIF-8 that could specifically interact with Cu²⁺ for enhanced selectivity toward Cu²⁺ detection.

Synthesis of fluorescent MOFs: live-cell imaging and sensing of a herbicide

Various metal–organic frameworks of Zn(ii) and Cd(ii) have been synthesized hydrothermally for the detection of herbicide (simazine) as well as nitro-aromatic compounds. Also these MOFs show live-cell imaging for MCF-7 cells.

Luminescent metal–organic framework-based phosphor for the detection of toxic oxoanions in an aqueous medium

Compound 1 has been utilized for the luminescence based visible detection of chromate, permanganate and phosphate ions in aqueous medium.

Two anthracene chromophore based metal–organic frameworks for gas adsorption and promising nitro aromatic sensing

Two novel metal–organic frameworks (MOFs) have been synthesized under solvothermal conditions. Studies on luminescence sensing show 1 and 2 are highly selective and recyclable in the detection of nitroaromatic explosives, especially for TNP.

Determination of adenosine triphosphate based on the use of fluorescent terbium(III) organic frameworks and aptamer modified gold nanoparticles

A thiol-labeled adenosine triphosphate (ATP) binding aptamer is covalently linked on the surface of gold nanoparticles (AuNPs). This warrants protection of the red AuNPs from aggregation in high salt condition. The dispersed AuNPs can quench the fluorescence of the Tb(III)-MOFs at 547 nm with the excitation wavelength of 290 nm. This is ascribed to the combined action of inner filter effect, dynamic quenching and fluorescence resonance energy transfer. If the aptamer binds ATP to form folded structures, the AuNPs aggregate in high salt medium and the green fluorescence of the Tb(III)-MOFs is recovered. This method shows good sensitivity and selectivity for ATP, and the linear range is from 0.5 to 10 μM of ATP with the detection limitat of 0.32 μM. It was applied to the determination of ATP in (spiked) human plasma with satisfactory recoveries (from 93.2% to 106.3%). Oppositely, when the unlabeled aptamer is used instead of thiol-labeled aptamer in this process, the ATP-aptamer complexes rather than unlabeled aptamer provide greater protection for AuNPs against salt-induced aggregation. It is found that when the aptamer covalently binds to AuNPs, the steric hindrance is dominant for the stabilization of AuNPs; for unlabeled aptamer, the electrostatic repulsion is responsible for their stability, irrespective of whether ATP is present or not. These two different forces lead to the aggregation or dispersion of AuNPs with addition of target in salt solution. Graphical abstractThe impact of two repulsive forces (electrostatic repulsion and steric repulsion) on the stabilization of gold nanoparticles, and its application in fluorescent terbium metal-organic frameworks as a nanoprobe for adenosine triphosphate.

CdII -Organic Frameworks Fabricated with a N-Rich Ligand and Flexible Dicarboxylates: Structural Diversity and Multi-Responsive Luminescent Sensing for Toxic Anions and Ethylenediamine

Three metal-organic frameworks {[Cd(L)(glu)]⋅3 H₂ O}_∞ (1), {[Cd₂ (L)₂ (adi)₂ ]⋅5 H₂ O}_∞ (2) and {[Cd(L)(sub)]⋅3 H₂ O⋅DMA }_∞ (3) (L=pyridine-3,5-bis(5-azabenzimidazole), H₂ glu=glutaric acid, H₂ adi=adipic acid and H₂ sub=suberic acid) were obtained under solvothermal conditions. Complex 1 shows a 2D (4,4) network constructing of Cd₂ -glu and Cd-L chains. Complex 2 presents a 2-fold interpenetrating 3D framework with pcu topology. Complex 3 is a 3D framework with cds topology. Three complexes with versatile structures were obtained by changing aliphatic dicarboxylate ligands with different lengths based on a N-rich ligand. Moreover, the fluorescence measurements indicate that complex 1 is a good multifunctional chemosensor for the detection of Cr₂ O₇ ^2- and MnO₄ ^- anions by fluorescence quenching effect, and ethylenediamine by fluorescence enhancement effect, with detection limits of 1.196 ppm, 0.551 ppm and 64.572 ppm, respectively. Both complexes 2 and 3 can selectively sense Cr₂ O₇ ^2- anion with detection limits of 1.126 ppm for 2 and 0.831 ppm for 3 by a fluorescence quenching effect.

Structural diversity, magnetic properties and luminescence of NiII, CoII and ZnII coordination polymers derived from 3,3'-[(5-carboxy-1,3-phenylene)bis(oxy)]dibenzoic acid and 1,10-phenanthroline

Three novel coordination polymers (CPs), namely poly[[di-μ-aqua-bis{μ₄-3,3'-[(5-carboxylato-1,3-phenylene)bis(oxy)]dibenzoato-κ⁵O¹:O^1',O³:O⁵:O^5'}bis(1,10-phenanthroline-κ²N,N')trinickel(II)] dimethylformamide 1.5-solvate trihydrate], {[Ni₃(C₂₁H₁₁O₈)₂(C₁₂H₈N₂)₂(H₂O)₂]·1.5C₃H₇NO·3H₂O}_n, (I), poly[[di-μ-aqua-bis{μ₄-3,3'-[(5-carboxylato-1,3-phenylene)bis(oxy)]dibenzoato-κ⁵O¹:O^1',O³:O⁵:O^5'}bis(1,10-phenanthroline-κ²N,N')tricobalt(II)] diethylamine disolvate tetrahydrate], {[Co₃(C₂₁H₁₁O₈)₂(C₁₂H₈N₂)₂(H₂O)₂]·2C₂H₇N·4H₂O}_n, (II), and catena-poly[[aqua(1,10-phenanthroline-κ²N,N')zinc(II)]-μ-5-(3-carboxyphenoxy)-3,3'-oxydibenzoato-κ²O¹:O³], [Zn(C₂₁H₁₂O₈)(C₁₂H₈N₂)(H₂O)]_n, (III), have been synthesized by the reaction of different metal ions (Ni²⁺, Co²⁺ and Zn²⁺), 3,3'-[(5-carboxy-1,3-phenylbis(oxy)]dibenzoic acid (H₃cpboda) and 1,10-phenanthroline (phen) under solvothermal conditions. All the CPs were characterized by elemental analysis, single-crystal and powder X-ray diffraction, FT-IR spectroscopy and thermogravimetric analysis. Complexes (I) and (II) have isomorphous structures, featuring similar linear trinuclear structural units, in which the central Ni^II/Co^II atom is located on an inversion centre with a slightly distorted octahedral [NiO₆]/[CoO₆] geometry. This comprises four carboxylate O-atom donors from two cpboda^3- ligands and two O-atom donors from bridging water molecules. The terminal Ni^II/Co^II groups are each connected to the central Ni^II/Co^II cation through two μ_1,3-carboxylate groups from two cpboda^3- ligands and one water bridge, giving rise to linear trinuclear [M₃(μ₂-H₂O)₂(RCOO)₄] (M = Ni²⁺/Co²⁺) secondary building units (SBUs) and the SBUs develop two-dimensional-networks parallel to the (100) plane via cpboda^3- ligands with new (3²·4)₂(3²·8³·9)₂(3⁴·4².8²·9⁴·10³) topological structures. Zinc complex (III) displays one-dimensional coordination chains and the five-coordinated Zn atom forms a distorted square-pyramidal [ZnO₃N₂] geometry, which is completed by two carboxylate O-atom donors from two distinct Hcpboda^2- ligands, one O atom from H₂O and two N atoms from a chelating phen ligand. Magnetically, CP (I) shows weak ferromagnetic interactions involving the carboxylate groups, and bridging water molecules between the nickel(II) ions, and CP (II) shows antiferromagnetic interactions between the Co²⁺ ions. The solid-state luminescence properties of CP (III) were examined at ambient temperature and the luminescence sensing of Cr₂O₇^2-/CrO₄^2- anions in aqueous solution for (III) has also been investigated.

Devising Chemically Robust and Cationic Ni(II)-MOF with Nitrogen-Rich Micropores for Moisture-Tolerant CO2 Capture: Highly Regenerative and Ultrafast Colorimetric Sensor for TNP and Multiple Oxo-Anions in Water with Theoretical Revelation

Metal-organic frameworks (MOFs) show distinctive superiority for carbon dioxide (CO₂) capture and luminescent sensing of toxic pollutants over other materials, where combination of both of these properties together with improvement of hydrolytic stability and pore functionality is critical to environmental remediation applications. The Ni(II) framework [Ni₂(μ₂-OH)(azdc)(tpim)](NO₃)·6DMA·6MeOH (CSMCRI-3) (tpim = 4,4',4″-(1H-imidazole-2,4,5-triyl)tripyridine, H₂azdc = azobenzene-4,4'-dicarboxylic acid, DMA = dimethylacetamide, CSMCRI = Central Salt & Marine Chemicals Research Institute), encompassing cationic [Ni₂(μ₂-OH)(CO₂)₂] SBUs, is solvothermally synthesized from nitrogen-rich and highly fluorescent organic struts. The noninterpenetrated structure, containing free nitrogen atom affixed microporous channels, is stable in diverse organic solvents and weakly basic and acidic aqueous solutions. The activated MOF (3a) exhibits strong CO₂-framework interaction and extremely selective CO₂ adsorption over N₂ (292.5) and CH₄ (11.7). Importantly, water vapor exposure does not affect the surface area and/or multiple CO₂ uptake-release cycles, signifying potential of the porous structure for long-term use under humid conditions. Aqueous-phase sensing studies illustrate extremely specific and ultrafast detection of explosive 2,4,6-trinitrophenol (TNP) via remarkable fluorescence quenching (K_SV = 1.3 × 10⁵ M^-1), with a 0.25 ppm limit of detection (LOD). Furthermore, 3a serves as unique luminescent probe for highly discriminative and quick responsive detection of three noxious oxo-anions (Cr₂O₇^2-, CrO₄^2-, MnO₄^-) in water via noteworthy turn-off responses and extreme low LODs (Cr₂O₇^2- 0.9; CrO₄^2- 0.29; MnO₄^- 0.25 ppm). It is imperative to stress the outstanding reusability of the MOF toward multicyclic sensing of all four major water contaminants, alongside visible colorimetric changes upon individual analyte detection. Mechanistic insights in light of the electron transfer route together with density functional theory calculations portray the influence of pore functionalization in framework-analyte interactions, including alternation in energy levels, where varying degrees of contribution of energy transfer explicitly authenticates high quenching of the material.

Two-dimensional Cd(ii) coordination polymer encapsulated by Tb3+ as a reversible luminescent probe for Fe3

A two-dimensional luminescent cadmium(ii) coordination polymer, [Cd(modbc)2] n (Cd-P); modbc = 2-methyl-6-oxygen-1,6-dihydro-3,4'-bipyridine-5-carbonitrile, was successfully synthesized by a solvothermal reaction and fully characterized. Cd-P exhibited excellent luminescence emission, and detected Cu2+, Co2+, Fe2+, Hg2+, Ni2+ and Fe3+ ions with high sensitivity and showed good anti-interference performance. After encapsulation of Tb3+ ions in Cd-P, the as-obtained fluorescent functionalized Tb3+@Cd-P maintained distinct chemical stabilities in different pHs and metal salt solutions. Subsequently, we explored the potential application of Tb3+@Cd-P as a probe for Fe3+ ions. A new and convenient method for individual identification of Fe3+ ions by the combination of Cd-P and Tb3+@Cd-P was successfully established. A possible sensing mechanism is discussed in detail.

A Cd-MOF as a fluorescent probe for highly selective, sensitive and stable detection of antibiotics in water

Recently, the pollution and damage caused by antibiotics in water have aroused serious concerns. In this situation, it is extremely important to develop a highly effective approach to detect antibiotics in water. In this contribution, we built a Cd-MOF material with stable fluorescence properties, using bbi = 1,4-bis(2-methyl-imidazol-1-yl)butane and H2L = 1,2-phenylenediacetic acid as organic ligands and Cd(NO3)2·4H2O as the metal node. The highly selective response of this MOF probe to ceftriaxone sodium (an antibiotic) can reach up to the ppb level in water, along with a fast response time, acid and alkali resistance, and anti-interference ability.