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Nowadays, lung cancer is a severe health burden worldwide and the major challenge faced in this disease is that more than half of the patients are diagnosed in later stages. The measurement of N-acetylneuraminic acid (NANA) levels, an important biomarker, could serve as a useful indicator for the early diagnosis of this disease. In this work, 1D coordination polymer Cd-CP2 was obtained and explored as a luminescence probe for detecting the urinary biomarker uric acid (UA) via a quenching effect. The presence of free carboxylic groups in the coordination polymer leads to the formation of Eu3+/Tb3+-functionalized samples, named Eu3+@Cd-CP2 and Tb3+@Cd-CP2, via post-synthesis modification (PSM). Both of these samples were able to sense NANA via a ratiometric effect with the enhancement of ligand-centered peaks and quenching of rare earth peaks. The luminescence probe has several appealing merits, including a high selectivity, excellent sensitivity, low detection limit (0.89 μM for Eu3+@Cd-CP2 and 0.19 μM for Tb3+@Cd-CP2), and fast response time (less than 2 min). Furthermore, these fluorescent materials were explored as logic gates and test papers for potential application. [ABSTRACT FROM AUTHOR]

Photocatalysis is considered as an effective technique for mitigating ecological risks posed by residual tetracycline (TC). To improve the efficiency of this technique, it is necessary to enable photocatalysts to produce highly reactive species, such as singlet oxygen (1O2). However, due to the high activation energy of 1O2, photocatalysts can hardly produce 1O2 without assistance from external oxidants. Herein, we find that the size-reduced α-Fe2O3 nanoparticles (∼ 4 nm) that anchored on g-C3N4 nanotube (α-Fe2O3@CNNT) can spontaneously generate 1O2 for degradation of TC. In comparison, only hydroxyl radical (·OH) can be produced by g-C3N4 nanotube loaded with ∼ 14 nm α-Fe2O3 nanoparticles (α-Fe2O3/CNNT). Owing to the high reactivity of the 1O2 species, the photocatalytic degradation rate (Kapp) of TC with α-Fe2O3@CNNT (0.056 min−1) was 1.8 times higher than that of α-Fe2O3/CNNT. The experimental results and theoretical calculations suggested that reducing the size of α-Fe2O3 nanoparticles anchored on g-C3N4 nanotube decreased the surface electron density of α-Fe2O3, which induces the generation of high-valent Fe(IV) active sites over α-Fe2O3@CNNT and turns the degradation pathway into a unique 1O2 dominated process. This study provides a new insight on the generation of 1O2 for effective degradation of environmental pollutant. [ABSTRACT FROM AUTHOR]

Two series of lanthanide-based metal–organic frameworks, namely {[Ln(BIPA-TC)0.5(DMA)2(NO3)]·DMA·H2O}n (1-Ln, Ln = Eu, Dy, Sm, Nd) and {[Ln2(BIPA-TC)1.5(DMA)3(H2O)2]·2DMA·2H2O}n (2-Ln, Ln = Eu, Dy, Sm, Nd), were successfully constructed via a solvent regulation strategy based on a π-electron rich tetra-carboxylate ligand (H4BIPA-TC). 1-Ln shows a 4-connected lvt topology with the point symbol of {42·84}, but 2-Ln displays a new 4,4,6-connected wxk1 topology with the point symbol of {43·83}4{46·66·83}2{86}. The solid-state luminescence property and the microporous nature of Eu-MOFs (1-Eu and 2-Eu) indicate that they can potentially be used as luminescent sensors. Fluorescence measurements indicate that Fe3+ exhibits the quenching effect for 1-Eu with the quenching efficiency of 93.1%. 2-Eu is the first MOF sensor for Mg2+ with the lowest detection limit of 1.53 × 10−10 mol L−1 and displays good recyclable capability. Simultaneously, in the presence of other metal ions (Ca2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Pd2+, Al3+, Cr3+and Fe3+), 2-Eu can maintain the selective sensing of Mg2+, indicating its potential for Mg2+ turn-on sensing. [ABSTRACT FROM AUTHOR]

Two enantiomorphic MgII/carboxylate coordination polymers [Mg(bpda)(H2O)4] n ( 1M and 1P) have been obtained by spontaneous resolution from achiral precursors, 2,2′-bipyridyl-3,3′-dicarboxylic acid (H2bpda) and Mg(NO3)2 ·6H2O, upon crystallization without any chiral auxiliary. X-ray structural analysis shows that chiral transmission from molecular axially chiral conformations to crystal chirality is established through concerted coordination and H-bonding interactions. In addition, the CD data, and the thermal and photoluminescence properties in the solid state have also been discussed. [ABSTRACT FROM AUTHOR]

The separation of C 8 aromatic isomers ( o X: o -xylene, p X: p -xylene, m X: m -xylene, and EB: ethylbenzene) remains an enormous challenge in industrial production due to their similar molecular structures and physical properties. Porous materials with suitable pore structures and selective recognition sites to discriminate the slight structural differences of isomers are imminently needed. In this paper, MIL-47(V) with a three-dimensional (3D) grid structure of 10.5 × 10.5 Å 2 and a one-dimensional (1D) diamond channel was selected as the adsorbent. However, the mechanism of the adsorption and separation of C 8 aromatic isomers in porous materials still needs to be understood. Given the importance of C 8 aromatic isomers' confinement in MIL-47(V) for adsorption and diffusion applications, it is important to understand C 8 aromatic isomers' behavior in MIL-47(V) . Here, we demonstrated from a simulation perspective that metal-organic frameworks MIL-47(V) with one-dimensional (1D) diamond channels can identify C 8 aromatic isomers. Molecular dynamics (MD) simulations have shown that organic ligands with guest response sites of MIL-47(V) can effectively distinguish between C 8 aromatic isomers by adaptation to the shape of a specific isomer. MIL-47(V) has high adsorption and an excellent separation sequence between C 8 aromatic isomers: o X > p X ≈ m X > EB. Significant differences exist in π-π superposition interactions between C 8 aromatic isomers and between C 8 aromatic isomers and the skeletons. This phenomenon is mainly caused by the unique pore structure and guest response characteristics of MIL-47(V) . This work is identified as a supplementary instruction to experimental research and is expected to provide profound insights into research on developing C 8 aromatic isomers' adsorption and separation and theoretical support.

One 3D Cd-MOF, namely, {[(HDMA) 2 ][Cd 3 (L) 2 ]·5H 2 O·2DMF} n ( LCU-124 , LCU indicates Liaocheng University), was synthesized from an ether-containing ligand 1,3-bis(3,5-dicarboxylphenoxy)benzene (H 4 L). Its Ln 3+ -postmodified samples, Eu 3+ @LCU-124 and Tb 3+ @LCU-124 , were obtained through cation exchange of dimethylamine cation (HDMA) with Eu 3+ and Tb 3+ . The successful entry of rare earth into LCU-124 by cation exchange modification was verified by IR, XRD, XPS, EDS mapping, and luminescence spectra. The proportion of Eu 3+ /Tb 3+ was adjusted during the modification process, leading to fluorescent materials with different emissions. Luminescence measurements indicated that these complexes exhibited interesting multiresponsive sensing activities toward biomarkers urine acid (UA), quinine (QN), and quinidine (QND). First, LCU-124 has a pronounced quenching effect toward UA with the detection limit of 31.01 μM. After modification, the visualization of the detection was improved significantly and the detection limit of Eu 3+ @LCU-124 was reduced to 0.868 μM. Second, when QN and QND were present in the suspensions of Eu 3+ @LCU-124 and Tb 3+ @LCU-124 , strong blue light emission peaks occurred, while the characteristic emission of Eu 3+ /Tb 3+ decreased, forming ratiometric fluorescent sensors with the detection limit in the range of 0.199-9.49 μM. The fluorescent probes have high selectivity, excellent sensitivity recycling, and fast response time (less than 1 min). Besides, a simple logic gate circuit and a range of luminescent mixed matrix membranes were designed to provide simple and fast detection of above biomarkers. Our work indicated that modification of Eu 3+ /Tb 3+ could improve the detection ability significantly.

The superamphiphiles exhibit broad prospects for fabricating stimuli-responsive emulsions. Because the superamphiphiles are assembled via noncovalent interactions, they have the advantage of fast response and high efficiency. Recently, a series of switchable emulsions using CO 2 -responsive superamphiphiles have been developed, which extends the applications of CO 2 -responsive materials in widespread field. However, there is still a lack of fundamental understanding on the switching mechanism related to the assembled structure of superamphiphiles at the oil-water interface. We employed molecular dynamics (MD) simulations to investigate the reversible emulsification/demulsification process of a responsive emulsion system stabilized by a recently developed responsive superamphiphile (BTOA), which consists of oleic acid (OA) and cationic amine (named 1,3-bis(aminopropyl)tetramethyldisiloxane, BT). The simulation results present the morphologies in both the emulsion and demulsification states. It is found that the ionized OA - and the protonated BT + together form an adsorption layer at the oil-water interface. The hydrophobic parts of BT + are inserted into the adsorption layer, and the two amine groups contact the water phase. This adsorption layer reduces the interfacial tension and stabilizes the emulsion. After the bubbling of CO 2 , the surfactants were fully protonated to OA and BT 2+ . Because of the changes in the molecular polarity, OA and BT 2+ entered the oil and water phases, respectively, resulting in demulsification. The structural and dynamical properties were analyzed to reveal the different intermolecular interactions that were responsible for the reversible reversibility of the emulsion. The observations are considered to be complementary to experimental studies and are expected to provide deeper insights into studies on developing responsive materials via supramolecular assemblies.

Two series of lanthanide-based metal-organic frameworks, namely {[Ln(BIPA-TC)0.5(DMA)2(NO3)]·DMA·H2O}n (1-Ln, Ln = Eu, Dy, Sm, Nd) and {[Ln2(BIPA-TC)1.5(DMA)3(H2O)2]·2DMA·2H2O}n (2-Ln, Ln = Eu, Dy, Sm, Nd), were successfully constructed via a solvent regulation strategy based on a π-electron rich tetra-carboxylate ligand (H4BIPA-TC). 1-Ln shows a 4-connected lvt topology with the point symbol of {42·84}, but 2-Ln displays a new 4,4,6-connected wxk1 topology with the point symbol of {43·83}4{46·66·83}2{86}. The solid-state luminescence property and the microporous nature of Eu-MOFs (1-Eu and 2-Eu) indicate that they can potentially be used as luminescent sensors. Fluorescence measurements indicate that Fe3+ exhibits the quenching effect for 1-Eu with the quenching efficiency of 93.1%. 2-Eu is the first MOF sensor for Mg2+ with the lowest detection limit of 1.53 × 10-10 mol L-1 and displays good recyclable capability. Simultaneously, in the presence of other metal ions (Ca2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Pd2+, Al3+, Cr3+and Fe3+), 2-Eu can maintain the selective sensing of Mg2+, indicating its potential for Mg2+ turn-on sensing.

With the careful modulation of the relative ratio of Y 3+ /Eu 3+ and Y 3+ /Tb 3+ , two series of bimetallic RE-CPs (Eu x Y 1- x and Tb x Y 1- x ) were successfully obtained through the isomorphous substitution method. Interestingly, the introduction of Y 3+ ions does not change the fluorescence characteristic peak of 1-Eu and 1-Tb, but enhances its fluorescence lifetime and quantum yield. Experimental and theoretical simulation results show the co-doping process changes the intramolecular energy transfer process and reduces the non-radiative transition resulting from concentration quenching. Eu 0.1 Y 0.9 and Tb 0.1 Y 0.9 with the largest luminescence lifetime were selected as the representative research objects, their potential application for the detection of toxic metal ions and organic molecules was further investigated. Interestingly, Eu 0.1 Y 0.9 and Tb 0.1 Y 0.9 demonstrate high sensitivity and good selectivity towards Fe 3+ , Cr 3+ and acetone. Besides, fine fluorescence visibility provides the necessary conditions for the preparation of simple and fast response fluorescent test papers in order to achieve real-time and convenient detection of these toxic materials., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)