Abstract Extracting uranium from real water samples remains a great challenge due to low uranium concentration, concentrated competing ions and volumes of water. The design and preparation of uranium ...adsorbents with high efficiency and affinity are still difficult. Herein, we presented a facile one‐pot strategy to obtain a novel metal organic framework (denoted as Mn‐NDISA) for stable and efficient trapping of low concentration uranium. Mn‐NDISA with a built‐in hydrophobic cavity can boost the absorption affinity to 1.99 × 10 6 mL g −1 through the cooperative capture composed of electrostatic interaction, coordination force and hydrogen binding. Owing to the coordination‐available oxygen sites in flexible framework, a rapid kinetic equilibrium was achieved in just 25 min. Moreover, these exceptional adsorption features enabled Mn‐NDISA to successfully capture the naturally occurring uranium traces (~ppb) in wastewater samples, making it one of the most influential absorbents toward UO 2 2+ ever reported. The experimental and theoretical studies revealed that the electrostatic attraction came from the surface negatively charged Mn‐NDISA and the positively charged UO 2 2+ . The coordination originated from Lewis basic hydroxyl, carbonyl groups, and Lewis acid UO 2 2+ , while hydrogen bonds further reinforced the as‐formed uranium binding complex. This research offered a promising cooperative capture strategy to improve the uranium affinity of the pristine MOF for trace contaminants removal in environmental remediation fields.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
In this work, a sensitive electrochemiluminescence (ECL) biosensor was proposed to detect protein kinase activity utilizing the signal amplification of bull serum albumin-templated gold nanoclusters ...(BSA-Au NCs) for graphite-like carbon nitride material (g-C3N4). In this system, g-C3N4 was utilized as a cathodic ECL emitter, and BSA-AuNCs were anchored to the phosphorylated peptides modified g-C3N4/GCE by AuS bond in the presence of adenosine 5′-γ-thio triphosphate (ATP-s) and protein kinase A (PKA). Attributed to the outstanding catalytic activity of BSA-AuNCs in the ECL process, the ECL intensity of this system shows 4.5-fold enhancement than that without BSA-AuNCs. Such enhancement in combination with the intensity of ECL signal and protein kinase activity enables us to fabricate an ultrasensitive ECL biosensor to detect PKA with low background. The proposed ECL platform can be utilized to analyse PKA activity of biological sample quantitatively and screen kinase inhibition qualitatively.
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•ECL biosensor based on the interaction between g-C3N4 and Au NCs has been designed.•Au NCs can act as a catalyst to efficiently magnify the ECL intensity of g-C3N4.•It provided a highly sensitive strategy for PKA activity detecting with a low detection limit.•The method proved excellent performance on the kinase inhibitor assay.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A green method was employed for synthesizing peptide-templated nanoclusters without requiring strong reducing agents. Using synthetic peptide-gold nanoclusters as fluorescence probes, a novel assay ...for detecting protein kinase is developed based on phosphorylation against carboxypeptidase Y digestion.
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•High selectivity imidazole was introduced as linkage in varying degree hydroxylation covalent organic polymers.•Benefiting from the introduction of hydroxyl groups, the uranium ...adsorption capacities were largely enhanced.•The TpDAB endowed prominent selectivity towards multiple metal ions including vanadium.•The hydroxyl groups significantly influenced the uranium coordination mechanism of imidazole functional group.
Highly effective and reliable adsorbents for uranium extraction are vital significant for environmental protection and social development. Herein, inspired by the interaction between imidazole affinity ligand of histidine and uranium, a series of varying degree hydroxylation imidazole linked covalent organic polymers were developed for the first time via one step facile reaction without any post treatment between 2,4,6-triformylphloroglucinol (Tp), 2,4,6-triformylresorcinol (Bd), 2,4,6-triformylphenol (Hb) and 3,3′-diaminobenzidine (DAB), denoted as TpDAB, BdDAB, and HbDAB, respectively. Benefiting from the hierarchical structure of the covalent organic polymer and synergistic effects originating from hydroxyl groups and imidazole linkages, TpDAB, BdDAB, and HbDAB displayed as the promising adsorbents for uranium extraction with high extraction ability and fast capture kinetics. X-ray photoelectron spectroscopy results revealed that both nitrogen atoms in imidazole and oxygen atom in hydroxyl took part in uranium coordination. With the increasing of hydroxyl group amounts, TpDAB achieved highest extraction capacity of uranium. Furthermore, TpDAB with imidazole affinity group possessed eminent selectivity for uranium in the multiple metal ions solution, and especiallyovercome the unavoidable problem of vanadium interfering with amidoxime adsorption uranium. This work provided a promising uranium extraction strategy with high selectivity and easy preparation for environmental protection and human health.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Covalent organic framework nanosheets (COF NSs) provide well-ordered π–π structures that can be used to develop luminescent materials. However, most COF NSs have problems of weak luminescence and low ...fluorescence quantum yield. In this work, we prepared covalent organic framework nanosheets (Bpy-NSs) with good water dispersibility, nitrogen-rich functional groups, and regular pore structure. We explored the coordination of Bpy-NSs with Al3+ to eliminate the fluorescence quenching process caused by photoinduced electron transfer (PET). Thus, the fluorescence “turn-on” signal linearly increases with Al3+ concentration, achieving a 15.7-fold improved in fluorescence, and the absolute fluorescence quantum yield increased from 0.15 to 1.74%. Furthermore, this is the first COF fluorescence sensor that can be used for high sensitivity and selectivity detection of Al3+ in the aqueous phase. We anticipate that the expansion of metal ions coordination strategy in the aqueous phase will not only significantly enhance the fluorescence of COF NSs but also extend the functional range of COF NSs.
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IJS, KILJ, NUK, PNG, UL, UM
•Magnetic MIP–Fe3O4@PNE NPs were facilely prepared for enantioselective recognition.•The microchip system can be used to separate various types of chiral compounds.•The MIP-based microchip system ...opened up an avenue for multiplex chiral compound assay.
A newly designed molecularly imprinted polymer (MIP) material was developed and successfully used as recognition element for enantioselective recognition by microchip electrophoresis. In this work, molecularly imprinted polymers were facilely prepared employing Fe3O4 nanoparticles (NPs) as the supporting substrate and norepinephrine as the functional monomer in the presence of template molecule in a weak alkaline solution. After extracting the embedded template molecules, the produced imprinted Fe3O4@polynorepinephrine (MIP–Fe3O4@PNE) NPs have cavities complementary to three dimensional shape of template molecules favoring high binding capacity and magnetism property for easy manipulation. The MIP–Fe3O4@PNE NPs prepared with l-tryptophan, l-valine, l-threonine, Gly-l-Phe, S-(−)-ofloxacin or S-(−)-binaphthol as template molecules were packed in the polydimethylsiloxane microchannel via magnetic field as novel stationary phase to successful enantioseparation of corresponding target analysts. The MIP–Fe3O4@PNE NPs-based microchip electrophoresis system exhibited strong recognition ability, excellent high-performance, admirable reproducibility and stability, which provided a powerful protocol for separation enantiomers within a short analytical time and opened up an avenue for multiplex chiral compound assay in various systems.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Extracting rare earth elements (REEs) from wastewater is essential for the growth and an eco-friendly sustainable economy. However, it is a daunting challenge to separate individual rare earth ...elements by their subtle differences. To overcome this difficulty, we report a unique REE nanotrap that features dense uncoordinated carboxyl groups and triazole N atoms in a two-fold interpenetrated metal-organic framework (named NCU-1). Notably, the synergistic effect of suitable pore sizes and REE nanotraps in NCU-1 is highly responsive to the size variation of rare-earth ions and shows high selectivity toward light REE. As a proof of concept, Pr/Lu and Nd/Er are used as binary models, which give a high separation factor of SF
= 796 and SF
= 273, demonstrating highly efficient separation over a single step. This ability achieves efficient and selective extraction and separation of REEs from mine tailings, establishing this platform as an important advance for sustainable obtaining high-purity REEs.
A novel electrochemical immunosensor based on a signal amplification strategy was developed for sensitive detection of carcinoembryonic antigen (CEA). Graphene/chitosan–ferrocene (GO/CS–Fc) was ...employed as the matrix to immobilize the primary antibodies (Ab1). Owing to the larger surface area, a large amount of Ab1 was captured on GO/CS–Fc sensor platform, thus amplifying the detection signal. Fe3O4/Au NPs were functionalized as the label to conjugate with the secondary antibodies (Ab2). Due to the homogeneous and narrow size distribution of Fe3O4/Au NPs, several Ab2 were bound on each nanoparticle, thus enhanced sensitivity was achieved by introducing the Fe3O4/Au NPs/Ab2 onto the electrode surface through “sandwich” immunoreactions. On the basis of p-aminophenol (AP) redox cycling amplification strategy, the developed immunosensor showed a 10-fold increase in detection signal compared to the immunosensor without Fe3O4/Au NPs labeling. The proposed immunosensor offered a sensitive determination of CEA in the range of 0.001–30ngmL−1 with a detection limit of 0.39pg/mL. This immunoassay method would open up a promising platform to detect various tumor markers for diagnosis of different cancers.
•Signal amplification strategy-based electrochemical immunosensor for detection of CEA•GO/CS–Fc was employed as the matrix to immobilize antibodies.•Enhanced sensitivity was achieved by introducing Fe3O4/Au NPs onto electrode surface.•p-Aminophenol redox cycling was utilized to amplify the electrocatalytic current.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Small molecules or metal ions can be employed as catalysts to accelerate metalloporphyrin formation. Herein, we for the first time report the coordination reaction between cadmium(II) and ...5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrin can be accelerated by nitrogen-doped graphene quantum dots (NGQDs). This catalytic reaction results in the change of the absorption of porphyrins and the fluorescence of NGQDs as a result of the inner filter effect (IFE) of the porphyrins on the assembled NGQDs. Both signals can be used for rapid and sensitive determination of metal ions. The present work promises a novel strategy for constructing sensors for metal ions.
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IJS, KILJ, NUK, PNG, UL, UM
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•A metal coordination polymer Zn-Vlm6 enriched with imidazole was synthesized to remove iodine.•The imidazole group and the free counter anion NO3– in Zn-Vlm6 play a vital role in the ...I2/I3− adsorption.•In the presence of excess competing anions, Zn-Vlm6 exhibited excellent selective removal of I3−.•Zn-Vlm6 could remove I3− in the actual aqueous environment (e.g., lake water, seawater).
Rationally designing a new adsorbent with highly selective and high adsorption capacity for removing I3− from water is still a significant challenge. Herein, we report an imidazole group-rich coordination polymer (CP) named Zn-Vlm6, which was constructed by the reaction of the 1-vinylimidazole (Vlm) and Zn2+ ions. Zn-Vlm6 showed excellent thermal and chemical stability (1 M HCl and 0.1 M NaOH). The abundance of positively charged imidazole groups and the free anti-anion NO3− in the backbone of Zn-Vlm6 results in strong electrostatic interactions and ion exchange between the material and the guest, in return, a high adsorption capacity for I3− (1680.7 mg g−1). In addition, the kinetics of I3− adsorption on Zn-Vlm6 followed the pseudo-second-order kinetic model and reached adsorption equilibrium within 3 min. More importantly, Zn-Vlm6 can selectively capture I3− in the presence of competing anions and selectively remove high up to 96.4% of I3− from different environments (e.g., lake water, seawater). Moreover, Zn-Vlm6 can also adsorb gaseous iodine up to 2470 mg g−1. This study shows that Zn-Vlm6 has promising applications for removing iodine in the gaseous state and from different aqueous phases.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
