A series of crystalline compounds were obtained from simple one-step hydrothermal reaction of copper nitrate, benzentricaboxylate and different Keggin polyoxometalates. Phosphotungstic acid ...immobilized in host matrix was selected for the first time as a recyclable and efficient catalyst in oxidative desulfurization process, under eco-sustainable conditions supported by the green oxidant O2 and the green extracting agent distilled water. The efficiency of desulfurization with air was studied and it is possible to use air as green oxidant in desulfurization. Moreover, the catalyst is effective for the desulfurization of real diesel.
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.
We demonstrate for the first time an interfacial polymerization method for the synthesis of high‐quality polyaniline‐modified graphene nanosheets (PANI/GNs), which represents a novel type of ...graphene/polymer heterostructure. The interfacial polymerization at a liquid–liquid interface allows PANI to grow uniformly on the surface of the GNs. An ultra‐high loading of Pt nanoparticles was then controllably deposited on the surface of the PANI/GNs to form a Pt/PANI/GNs hybrid. The obtained composites were characterized by scanning electron microscopy, transmission electron microscopy, energy‐dispersive spectrometry, X‐ray diffraction, X‐ray photoelectron spectroscopy, and thermogravimetric analysis. The Pt/PANI/GNs hybrid shows excellent electrocatalytic activity toward methanol oxidation and oxygen reduction. H2O2 and glucose were used as two representative analytes to demonstrate the sensing performance of a Pt/PANI/GNs‐modified electrode. It is found that this sensing element shows high sensitivity and a low detection limit for H2O2 and glucose. The results demonstrate that the Pt/PANI/GNs hybrid may be an attractive and advanced electrode material with potential applications in the construction of electrochemical sensors and biosensors.
Hybrids make sensors! High‐quality polyaniline‐modified graphene nanosheets (PANI/GNs) were prepared by using an interfacial polymerization method, then an ultra‐high loading of Pt nanoparticles (Pt NPs) was controllably deposited on the surface of PANI/GNs to form a Pt/PANI/GNs hybrid (see figure). The resultant hybrid shows high electrocatalytic activity toward the electrooxidation of methanol and reduction of oxygen.
In this study, impacts of nanoplastic on the pure and mixed anaerobic digestion systems were investigated. Results showed the growth and metabolism of Acetobacteroides hydrogenigenes were partly ...inhibited by nanoplastic existed in the pure anaerobic digestion system. The anaerobic digestion of sewage sludge was also obviously inhibited by nanoplastic existed in the mixed anaerobic digestion system. Both the methane yield and methane production rate of the mixed anaerobic digestion system showed negative correlation with the nanoplastic concentration. Compared with anaerobic digestion system without nanoplastic, methane yield and maximum daily methane yield at the nanoplastic concentration of 0.2g/L decreased for 14.4% and 40.7%, respectively. In addition, the start-up of mixed anaerobic digestion system was prolonged by addition of nanoplastic. Microbial community structure analysis indicated the microbial community structures were also affected by nanoplastic existed in the system. At the nanoplastic concentration of 0.2g/L, the relative abundances of family Cloacamonaceae, Porphyromonadaceae, Anaerolinaceae and Gracilibacteraceae decreased partly. Conversely, the relative abundances of family Anaerolinaceae, Clostridiaceae, Geobacteraceae, Dethiosulfovibrionaceae and Desulfobulbaceae improved partly.
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•Impacts of nanoplastic on anaerobic digestion system was investigated•Exposure to nanoplastic leads to inhibition of anaerobic digestion system•The inhibitory effect was positive correlation with nonaplastic's concentration•Different microorganism showed unequal response to nanoplastic
Copper is a highly toxic environmental pollutant with bioaccumulative properties. Therefore, sensitive detection of Cu2+ is very important to prevent over-ingestion, and visual detection is preferred ...for practical applications. In this work, we developed a simple and environmental friendly approach to synthesize hyperbranched polyethyleneimine-protected copper nanoclusters (hPEI-Cu NCs) with great stability against extreme pH, high ionic strength, thiols etching and light illumination, which were then conjugated to the surface of silica coated CdSe quantum dots (QDs) to design a ratiometric fluorescence probe. In the presence of different amounts of Cu2+ ions, the fluorescence of Cu NCs can be drastically quenched, while the emission from QDs stayed constant to serve as a reference signal and the color of the probe changed from yellow-green to red, resulting in ratiometric and visualization detection of Cu2+ ion with high accuracy. The detection limit for Cu2+ was estimated to be 8.9 nM, much lower than the allowable level of Cu2+ in drinking water (∼20 μM) set by U.S. Environmental Protection Agency. Additionally, this probe can be also applied for the determination of Cu2+ ion in complex real water samples.
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•We developed a ratiometric fluorescence probe for ratiometric and visualization detection of copper ions.•Copper nanoclusters was conjugated to silica coated CdSe quantum dots to design a ratiometric fluorescence probe.•Highly sensitive and visualized detection of Cu2+ was achieved.•This method provided a built-in correction for environmental interference.
Uranium is a key element in the nuclear industry and also a global environmental contaminant with combined highly toxic and radioactive. Currently, the materials based on post-modification of ...amidoxime have been developed for uranium detection and adsorption. However, the affinity of amidoxime group for vanadium is stronger than that of uranium, which is the main challenge hindering the practical application of amidoxime-based adsorbents. Herein, we synthesized a fluorescent covalent organic framework (TFPPy-BDOH) through integrating biphenyl diamine and pyrene unit into the π-conjugated framework. TFPPy-BDOH has an excellent selectivity to uranium due to the synergistic effect of nitrogen atom in the imine bond and hydroxyl groups in conjugated framework. It can achieve ultra-fast fluorescence response time (2 s) and ultra-low detection limit (8.8 nM), which may be attributed to its intrinsic regular porous channel structures and excellent hydrophilicity. More excitingly, TFPPy-BDOH can chemically reduce soluble U (VI) to insoluble U (IV), and release the binding site to adsorb additional U (VI), achieving high adsorption capacity of 982.6 ± 49.1 mg g−1. Therefore, TFPPy-BDOH can overcome the challenges faced by current amidoxime-based adsorbents, making it as a potential adsorbent in practical applications.
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•A fluorescent COF (TFPPy-BDOH) is synthesized by a one-step method.•TFPPy-BDOH has ultra-fast fluorescence response time for UO22+.•TFPPy-BDOH can selectively chemically reduce soluble U(VI) to insoluble U(IV).•TFPPy-BDOH achieves high sensitivity and selectivity for detecting and capturing UO22+ in harsh environments.
Lanthanide coordination polymer nanoparticles (Ln-CPNs) have been recently demonstrated as excellent platforms for biomolecule detection. In this work, we synthesized novel cerium coordination ...polymer nanoparticles ATP-Ce-Tris CPNs in a simple and quick way using ATP molecules as the biocompatible ligands to Ce3+ ions in tris(hydroxymethyl)aminomethane hydrochloric (Tris-HCl) solution. In view of the excellent free radical scavenging property of cerium compounds, which is ascribed to the mixed valence state (Ce3+, Ce4+) and the reversible switch from Ce3+ to Ce4+, the synthesized ATP-Ce-Tris CPNs was used as artificial peroxidase to selectively and sensitively detect H2O2. The sensing mechanism depends on the oxidation of the fluorescent ATP-Ce(III)-Tris CPNs to nonfluorescent ATP-Ce(IV)-Tris CPNs by H2O2. Compared with those inorganic cerium oxide sensors, this kind of fluoresence ATP-Ce-Tris CPNs sensor needs no additional organic redox dye, such as ABTS (2,20-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), TMB (3,3,5,5-tetramethylbenzidine), or fluorescein as signal molecules. Moreover, such ATP-Ce-Tris CPNs sensor exhibited a more sensitive response to H2O2 with a detection limit down to 0.6 nM, which is 2 orders of magnitude lower than those of cerium oxide sensors. This sensing platform was further extended to the detection of glucose in combination with the specific catalytic effect of glucose oxidase (GOx) for the oxidation of glucose and formation of H2O2.
A simple and sensitive photoluminescence (PL) assay for the activity of a protein kinase based on the selective aggregation of phosphorylated peptide–graphene quantum dot (GQD) conjugates triggered ...by Zr4+ ion coordination has been established. With more sophisticated design of the peptide substrate sequences, detecting other enzymes could also be possible. Under optimal conditions, a linear relationship between the decreased PL intensity of peptide–GQD conjugates and the concentration of casein kinase II (CK2) in the range from 0.1 to 1.0 unit mL–1 with a detection limit of 0.03 unit mL–1 (3σ) was obtained. The EC50 value (i.e., the enzyme concentration producing 50% substrate conversion) for CK2 was evaluated to be 0.34 unit mL–1. The proposed method showed potential applications in kinase inhibitor screening. To demonstrate the potential of this GQD-based platform for screening of kinase inhibitors in real biological systems, the inhibition of CK2 phosphorylation activity by four different inhibitors (ellagic acid, 5,6-dichlorobenzimidazole-l-β-d-ribofuranoside, emodin, and quercetin) was tested in human serum by comparing signals from samples incubated with the inhibitors against that without any inhibitor. As expected, in the presence of inhibitors, the PL intensity increased with increasing inhibitor efficiency. The IC50 value (inhibitor concentration producing 50% inhibition) for ellagic acid was estimated to be 0.041 μM. The developed protocol provides a new and promising tool for the analysis of both the enzyme and its inhibitors with low cost and excellent performance.
Platinum nanoparticles (Pt NPs) with uniform size and high dispersion have been successfully assembled on poly(diallyldimethylammonium chloride) functionalized graphene oxide via a sodium borohydride ...reduction process. The loading concentration of Pt NPs on graphene can be adjusted in the range of 18–78 wt %. The obtained Pt/graphene nanocomposites are characterized by transmission electron microscopy, high resolution transmission electron microscopy, energy dispersive spectrometry, X-ray diffraction, and thermogravimetric analysis. The results show that the Pt NPs with sizes of approximate 4.6 nm uniformly disperse on graphene surface for all Pt loading densities. Electrochemical studies reveal that the Pt/graphene nanocomposites with electrochemically active surface area of 141.6 m2/g show excellent electrocatalytic activity toward methanol oxidation and oxygen reduction. The present method is promising for the synthesis of high performance catalysts for fuel cells, gas phase catalysis, and sensors.
The pivotal roles of phosphatidylinositol 3-kinases （PI3Ks） in human cancers have inspired active development of small molecules to inhibit these lipid kinases. However, the first-generation pan-PI3K ...and dual-PI3K/mTOR inhibitors have encountered problems in clinical trials, with limited efficacies as a monotherapeutic agent as well as a relatively high rate of side effects. It is increasingly recognized that different PI3K isoforms play non-redundant roles in particular tumor types, which has prompted the development of isoform-selective inhibitors for pre-selected patients with the aim for improving efficacy while decreasing undesirable side effects. The success of PI3K isoform-selective inhibitors is represented by CAL101 （Idelalisib）, a first-in-class PI3Kδ-selective small-molecule inhibitor that has been approved by the FDA for the treatment of chronic lymphocytic leukemia, indolent B-cell non-Hodgkin’s lymphoma and relapsed small lymphocytic lymphoma. Inhibitors targeting other PI3K isoforms are also being extensively developed. This review focuses on the recent progress in development of PI3K isoform-selective inhibitors for cancer therapy. A deeper understanding of the action modes of novel PI3K isoform-selective inhibitors will provide valuable information to further validate the concept of targeting specific PI3K isoforms, while the identification of biomarkers to stratify patients who are likely to benefit from the therapy will be essential for the success of these agents.
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