yi Yang

A novel highly luminescent LnMOF film: a convenient sensor for Hg2+ detecting

A highly luminescent LnMOF {[Eu2(bqdc)3(H2O)(DMF)3]·0.5DMF·H2O}n (1, bqdc = 2,2′-biquinoline-4,4′-dicarboxylate) was designed and synthesized. It was characterized by single crystal X-ray diffraction, PXRD, TGA, EA and FT-IR. A new strategy for preparing mechanically robust MOF thin films was developed by electrodeposition in combination with subsequent solvothermal synthesis. A portable sensor device prototype consisting of a film of 1 was conveniently fabricated by using this new strategy and this sensor device exhibits a highly selective response to Hg2+. Its luminescence quenching can be distinguished clearly with the naked eye when illuminated by a handy UV banknote detector. The diffusion kinetics of Hg2+ into the LnMOF film is first proposed.

A bioaccumulative cyclometalated platinum(II) complex with two-photon-induced emission for live cell imaging

The cyclometalated platinum(II) complex [Pt(L)Cl], where HL is a new cyclometalating ligand 2-phenyl-6-(1H-pyrazol-3-yl)pyridine containing C(phenyl), N(pyridyl), and N(pyrazolyl) donor moieties, was found to possess two-photon-induced luminescent properties. The two-photon-absorption cross section of the complex in N,N-dimethylformamide at room temperature was measured to be 20.8 GM. Upon two-photon excitation at 730 nm from a Ti:sapphire laser, bright-green emission was observed. Besides its two-photon-induced luminescent properties, [Pt(L)Cl] was able to be rapidly accumulated in live HeLa and NIH3T3 cells. The two-photon-induced luminescence of the complex was retained after live cell internalization and can be observed by two-photon confocal microscopy. Its bioaccumulation properties enabled time-lapse imaging of the internalization process of the dye into living cells. Cytotoxicity of [Pt(L)Cl] to both tested cell lines was low, according to MTT assays, even at loadings as high as 20 times the dose concentration for imaging for 6 h.

An electrodeposited lanthanide MOF thin film as a luminescent sensor for carbonate detection in aqueous solution

A luminescent lanthanide MOF-based thin film [{[Eu(HBPTC)(H2O)2]·2DMF}n] (BPTC = benzophenone-3,3′,4,4′-tetracarboxylate) was successfully fabricated by electrodeposition in an anhydride system. In this approach, HO− anions will accumulate near the cathode while applying a direct current in nitrate solution, followed by benzophenone-3,3′,4,4′-tetracarboxylic dianhydride (BTDA) hydrolysis and the consequent growth of MOFs directly on an electrode surface. The influence of the concentration of the electrolyte, current density, and conductive salt on the synthesis of MOF films were investigated. We demonstrate that the carboxylic acid ligands can be replaced by the anhydride to fabricate the lanthanide MOF-based thin film by cathodic electrodeposition. Moreover, photoluminescent properties of this film were investigated and the photoluminescent measurement indicated that this luminescent MOF thin film is a highly selective sensor for carbonate in aqueous solution.

Vertically aligned In2O3 nanorods on FTO substrates for photoelectrochemical applications

Vertically aligned In2O3 nanorod arrays (NRAs) were obtained by annealing the as-prepared In(OH)3 precursors that grew directly on FTO substrates via a simple template-free electrochemical assembly process. The absorption edges of In2O3 NRAs show a red-shift to the visible region, and a remarkable photocurrent response under visible light illumination (λ ≥ 390 nm) in photoelectrochemical cells.

Lanthanide CPs: the guest-tunable drastic changes of luminescent quantum yields, and two photon luminescence

Four kinds of guest-driven lanthanide coordination polymers (CPs) have been synthesized. They have similar formula: [Tb(NPA)3CH3CN]n (1, H-NPA = N-phenylanthranilic acid), {[Tb(NPA)3CH3OH]CH3OH}n (2), [Ln(NPA)3DMF]n (Ln = Tb (3a), Gd (3b), Eu (3c)), and [Tb(NPA)3DMSO]n (4). These complexes were characterized by single-crystal diffraction, PXRD, FT-IR, TGA, DTA, EA, UV-vis spectra and luminescence lifetime measurements. They are all highly thermostable, acid and base resistant. The luminescence quantum yields (QY) of Tb3+ complexes: 1, 2, 3a and 4 are 4.0%, 9.0%, 44% and 46% respectively. Interestingly, there is a drastic change from 4.0% to 46% in luminescence QY by exchanging the coordination solvent, the oscillation of small molecule near the Tb3+ causes the drastic change. Furthermore, the octupolar-like structure of 4 has a high two-photon luminescence.

A New Luminescent Terbium 4‐methylsalicylate Complex as a Novel Sensor for Detecting the Purity of Methanol

A new dinuclear terbium complex [Tb2(4‐msal)6(H2O)4]·6H2O (1) (4‐msal = 4‐methylsalcylate) was synthesized. Its structure was determined by single crystal X‐ray diffraction, and the complex was characterized by PXRD, FT‐IR, fluorescence, TGA and DTA. Complex 1 exists as discrete molecules that are linked by extensive O–H … O hydrogen bonds into a 3D network. The luminescence lifetimes of 3 μm methanol solution and solid sample of 1 are 1.321 and 1.009 ms, respectively. The quantum yield of solid sample is 6.0%. The luminescence quenched more than 50% when 3% (vol/vol) different impurities (acetone, acetonitrile, chloroform, dichloromethane, dioxane, DMF, DMSO, ethanol, ether, ethyl acetate, glycol, H2O, hexane, TEA, THF and toluene or their mixture) were added. The inverse linear relationship between the Lg value of fluorescence intensity and the volume ratio of the minor component (to a maximum of 20%) is interpreted in terms of LgI = a−bX (I: luminescence intensity; X: volume ratio of impurities in methanol; a, b are constants). So 1 is a potential luminescent sensor for analyzing the purity of methanol.

A luminescent terbium coordination polymer for sensing methanol

Two isostructural one-dimensional lanthanide coordination polymers, with the general formula {[Ln(aip)(H2O)5]·0.5(bdc)·3H2O}n [Ln = Eu (1), Tb (2); H2aip = 5-aminoisophthalic acid, H2bdc = 1,4-benzenedicarboxylic acid], have been synthesized by a diffusion technique at room temperature. Their structures were identified by X-ray diffraction. Complex 2 exhibits green emission, corresponding to the 5D4 → 7FJ (J = 6–3) transitions of the Tb3+ ion. Significantly, when 2 was immersed in different organic solvents, it had a unique response to methanol compared to other solvents. Furthermore, 2 displayed highly sensitive and selective luminescence quenching to methanol with the ignorable interference of other small-molecule organics. This makes it a potential luminescence sensor for actual application in recognizing methanol.

One step cathodically electrodeposited [Tb2(BDC)3(H2O)4]n thin film as a luminescent probe for Cu2+ detection

A luminescent Ln-CP film of [Tb2(BDC)3(H2O)4]n (1) [BDC: p-Benzenedicarboxylate anion] is fabricated using electrodeposition method on FTO (fluorine-doped tin oxide glass). It is a one-step and highly effective electrochemical method at room temperature. The influence of reaction conditions on the thickness of film 1 was investigated. A smooth and adherent thin film 1 is obtained at the appropriate concentrations of Tb(NO3)3 (0.01 M) and H2BDC (0.015 M) with 0.3 mA cm−2 (0.050 M NH4NO3) for 20 minutes. The composition of the film was confirmed by X-ray diffraction. The sensing properties of the film have been studied. The results show that thin film 1 exhibits selective detection of Cu2+ in DMF solution. The luminescent intensity is inversely proportional to the concentration of Cu2+ ions and displays a linear region over the range of 1 × 10−5 −1 × 10−3 M. Furthermore, a probable quenching mechanism is discussed.

Mixed matrix membranes incorporated with Ln-MOF for selective and sensitive detection of nitrofuran antibiotics based on inner filter effect

The detection of antibiotics is critical and challenging due to the pervasive use of antibiotics had inevitably brought some negative impacts on ecosystem and human health. Herein, we reported an anti-interfere ability enhanced luminescent sensor of lanthanide metal-organic framework (Ln-MOF) filled mixed matrix membranes (MMMs), which combining the processibility of poly(methyl methacrylate) (PMMA) polymer with Ln-MOF of {[Tb2(AIP)2(H2O)10]·(AIP)·4H2O}n (Tb-AIP, where AIP is 5-aminoisophthalate) fillers. The as-fabricated Tb-AIP MMMs are stable in water with a wide pH range and exhibit characteristic blue emission of Tb3+. Significantly, the Tb-AIP MMMs show highly selective and sensitive to nitrofuran antibiotics (NFAs) via inner filter effect (IFE), and yet remain unaffected not only by other common antibiotics but also by other types of analytes (metal ions and anions) that may coexist. The limits of detection for nitrofurantoin (NFT) and nitrofurazone (NFZ) are 0.30 and 0.35μM, respectively. As a proof of concept, the proposed MMMs sensor are demonstrated to be feasible for application in detecting NFAs in original water of Pearl River and bovine serum samples, the corresponding quenching constants and limits of detection are similar to their standard detections in an acceptable range. Furthermore, this MMMs sensor for NFAs detection was reversible after washing with deionized water. The luminescent Ln-MOF filled MMMs presented here provides a functional platform for simple yet useful in sensing of NFAs in environment and biology systems.

Tb(III) postsynthetic functional coordination polymer coatings on ZnO micronanoarrays and their application in small molecule sensing

A series of luminescent coatings of Tb3+ functionalized coordination polymers (CPs) consolidated by different multi-carboxylic ligands [1,4-benzenedicarboxylate, 1,3,5-benzenetricarboxylate, 2,6-naphthalenedicarboxylate] are fabricated on ZnO micronanoarrays. These hybrid luminescent coatings of Tb(III)@CPs/ZnO (Tb(III) functionalized CP/ZnO) are prepared by solvothermal synthesis and a postsynthetic functionalization (PSF) approach. Tb(III)@MOF-5/ZnO exhibits a highly detectable luminescence response for acetone molecules, and its structure, composition and morphology are characterized by XRD, EDS, ICP and SEM, respectively. It is first demonstrated that a lanthanide ion functionalized hybrid micronano-CP/ZnO coating is used as a small molecule sensor successfully.