Search

Herein, we have developed a rhodium-catalyzed C–H functionalization and subsequent intramolecular ring-opening/cyclization of vinylene carbonate with 2-pyrrolyl/indolylanilines, which leads to oxazolidinones in moderate to good yields. In this transformation, vinylene carbonate only eliminates one oxygen atom rather than –CO3 or CO2. Furthermore, some control experiments are conducted to elucidate the reaction mechanism. [ABSTRACT FROM AUTHOR]

A Lewis-acid-promoted cyclization reaction of benzoyl chlorides with 2-(4,5-dihydrooxazol-2-yl)anilines, which can offer a series of N3-chloroethyl quinazolinones, is disclosed. The reaction is compatible with the functional groups of the substrates; environment-friendly AlCl3 is probably the chloride source. Moreover, the addition of NH4SCN can also produce a range of N3-thiocyanatoethyl quinazolinones in moderate-to-good yields. [ABSTRACT FROM AUTHOR]

The development of high capacity, low cost, and high safety cathode materials for rechargeable aqueous zinc-ion batteries (ZIBs) is an ongoing challenge. Herein, CuV2O6 nanowires are prepared by a facile hydrothermal method to be used as a high-capacity cathode material for ZIBs. The sample displays an initial discharge capacity of 338 mA h g−1 at a current density of 100 mA g−1 and a capacity of 143 mA h g−1 remained at 5 A g−1 after 1200 cycles with a retention of ∼100% except for the initial capacity decay. Systematic structural and elemental characterization confirms that the reduction/oxidation of Cu2+/Cu0 is reversible during the electrochemical process. This work provides new prospects for designing more cathode materials based on the displacement reaction mechanism for Zn-ion batteries. [ABSTRACT FROM AUTHOR]

In this study, a simple, robust, label-free electrochemical biosensor based on the ligase chain reaction (LCR) was developed for the highly sensitive and selective detection of single nucleotide polymorphisms (SNPs) using Fe(CN)63−/Fe(CN)64− as a redox indicator. High sensitivity and specificity were achieved by using the LCR, which employs a thermostable and single-base discerning Hifi Taq DNA ligase to repeatedly ligate adjacently hybridized LCR-specific probes during thermal cycles, resulting in the highly specific exponential amplification of DNA targets. The electrochemical signal of the biosensor was further decreased using stem-loop probe DNA (SL-DNA), which specifically hybridized with LCR products on the electrodes. The linear dynamic range and high sensitivity of the mutant DNA (MutDNA) and wild-type DNA (WtDNA) LCR-based electrochemical biosensors for the detection of MutDNA and WtDNA were studied in vitro, with a broad linear dynamic range of 10 aM to 10 pM and detection limits of 1.18 aM and 0.35 aM, respectively. In addition, the MutDNA and WtDNA LCR-based electrochemical biosensors were able to accurately detect allele frequency changes as low as 0.1%. In summary, the developed LCR-based electrochemical biosensor provides a useful platform to monitor SNPs in a highly sensitive and specific manner. [ABSTRACT FROM AUTHOR]

The rational design and construction of supercapacitor electrode materials with prominent energy and power density play an indispensable role for their potential application in energy storage devices. In this work, NiCo2O4 nanowires grown on Ni foam have been synthesized through a facile hydrothermal approach, revealing a large capacitance and superior cycling stability with 80.3% capacitance retention after 20 000 cycles. The asymmetric supercapacitors are fabricated based on NiCo2O4 nanowire electrodes, which deliver an energy density of 27.4 W h kg−1 at a power density of 493.2 W kg−1 and an excellent cycle life with 79.2% capacitance retention after 10 000 cycles. [ABSTRACT FROM AUTHOR]

A new sensitive fluorescence turn-on detection of gamma-radiation is reported by taking advantage of aggregation induced-emission (AIE) behaviour of the tetraphenylethylene unit and the cascade radiochemical and protonation reactions. [ABSTRACT FROM AUTHOR]

In this study, a novel screening approach is presented, merging capillary electrophoresis analysis with an enzymatic assay employing immobilized α-glucosidase. A metal–organic framework composite membrane was devised for α-glucosidase immobilization. Employing polyvinylidene fluoride (PVDF) as the substrate material, it was functionalized with dopamine, creating a polydopamine composite layer. This layer acted as a covalent linker, anchoring Zn2+, which subsequently chelated with the organic ligand 2-ethylimidazole, leading to the self-assembly of a three-dimensional porous framework ZIF-8. This structure facilitated the in situ encapsulation of α-glucosidase. Characterization techniques including scanning electron microscopy, Fourier transform infrared-attenuated total reflectance spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction validated the composite material's structure. A thorough investigation of various parameters affecting immobilization was conducted. The immobilized α-glucosidase exhibited enhanced pH tolerance, thermal stability, and remarkable reusability, retaining 79.3% of its original activity over 10 cycles, with a batch-to-batch reproducibility of 5.9% (n = 5). Its Michaelis–Menten constant (Km) was determined to be 2.85 mM. Application of this immobilized enzyme in screening potential inhibitors from 13 traditional Chinese medicines revealed Sanguisorba radix as the most potent inhibitor. This study underscores the potential of this immobilized enzyme screening strategy for identifying enzyme inhibitors in traditional Chinese medicines. [ABSTRACT FROM AUTHOR]

A biosensor that can detect biomarkers accurately, quickly, and conveniently is important for the diagnosis of various diseases. However, most of the existing detection methods require sample extraction, which makes it difficult to detect and image intracellular molecules or to detect two different types of biomarkers simultaneously. In this study, we constructed a DNA tetrahedral nanoprobe (DTP) capable of detecting both miR378 and telomerase, both of which are tumor markers. In the presence of miR378, FAM on the molecular beacon of DTP fluoresced via Förster resonance energy transfer (FRET), and the limit of detection was 476 pM with excellent specificity. When present, telomerase binds to telomerase substrate (TS) primers, extending the repeat sequence (TTAGGG)n to trigger Cy3 fluorescence. A strong linear relationship existed between the fluorescence intensity of Cy3 and the number of HeLa cells. The limit of detection was 800 HeLa cells. In addition, DTP was less cytotoxic to and biocompatible with HeLa cells and fluoresced only in cancer cells, which can help to sensitively distinguish between normal and cancer cells. In conclusion, DTP can simultaneously detect the content of miR378 and activity of telomerase and realize intracellular imaging, which has broad application prospects in early cancer diagnosis and treatment. [ABSTRACT FROM AUTHOR]

As a promising candidate to replace lithium-ion batteries, rechargeable aqueous zinc ion batteries (AZIB) are receiving increasing attention due their high energy density, high safety, low cost and environmental friendliness. In this study, metal ions may be introduced into the interlayer gap of layered vanadium oxide nanobelts through a one-step hydrothermal process, without changing their original structure. Moreover, we have demonstrated by density functional theory computations that Mn metal ions not only serve as structural pillars but also enhance the conductivity of MnxVO2·0.2H2O, facilitating the migration of Zn ions. As a result, the electrochemical performance of MnxVO2·0.2H2O as an AZIB cathode has significantly improved; after 100 cycles at 0.5 A g−1, it exhibits a high reversible capacity of 350 mA h g−1. With a high current density of 5 A g−1, the initial capacity can still reach 295 mA h g−1. This paper suggests an effective method to maximize the efficiency of AZIB electrode materials. [ABSTRACT FROM AUTHOR]

Herein, we report a simple and facile sequential hydrothermal process for the synthesis of Co3O4 nanowire@NiO nanosheet arrays (CNAs). The as-synthesized CNAs were characterized in detail using various analytical techniques, which confirmed the high crystallinity, purity, and high-density growth of these nanomaterials. From an application point of view, the as-synthesized CNAs were directly used as supercapacitor electrodes, revealing a specific capacitance of up to 2018 mF cm−2 at a current density of 2 mA cm−2. Furthermore, a flexible asymmetric supercapacitor was fabricated using the as-synthesized CNAs as the anode and activated carbon as the cathode, which revealed a specific capacitance of 134.6 mF cm−2 at a current density of 2 mA cm−2. In addition, the supercapacitor showed excellent capacity retention of 73.5% after 10 000 cycles at a current density of 10 mA cm−2. [ABSTRACT FROM AUTHOR]

The first example of Ni-catalyzed halogenation of (hetero)aryl C–H bonds with lithium halides (LiX, X = Br, I, Cl) using PIP as a removable directing group is reported. This protocol provides an efficient access to ortho-halogenated (hetero)arenes with operational simplicity, good functional group tolerance, and large-scale synthesis. [ABSTRACT FROM AUTHOR]

A fast and sensitive method was established for an in-solution selection of cancer cell-targeting peptides at “single-residue resolution” by using the switchable fluorescence of tetraphenylethylene. The selected peptides have potential for biomarker tracing and can be used for targeted delivery of different cargos into living cancer cells. [ABSTRACT FROM AUTHOR]

A two-channel responsive and AIE-active fluorescent probe was developed to selectively detect superoxide anions in living cells, which can be used to track the endogenous superoxide anion level when cells undergo apoptosis and inflammation. [ABSTRACT FROM AUTHOR]

In this paper, a synergist complex of Ni(ii) with naphthalene-2-sulfonic acid (HNS) and n-hexyl 4-pyridinecarboxylate ester (LI), which are corresponding short chain analogues of active synergistic extractants dinonylnaphthalene sulfonic acid (HDNNS) and 2-ethylhexyl 4-pyridinecarboxylate ester (4PC, LII), was prepared and characterized by Nuclear Magnetic Resonance (1H-NMR), elemental analyses, Fourier Transform Infrared Spectroscopy (FT-IR) and Electrospray Ionization Mass Spectrometry (ESI-MS) spectroscopic studies. Single crystals of the nickel synergist complex have been grown from a methanol/water (10/1) solution and analyzed by single crystal X-ray diffraction. The crystal structure of the nickel synergist complex shows that Ni(ii) is coordinated by four water molecules and two monodentate LI ligands and there is no direct interaction of the Ni(ii) with sulfonic oxygen atoms of naphthalene-2-sulfonic acid anions, while hydrogen-bonded interactions of the coordinated water molecules with sulfonic oxygen atoms of naphthalene-2-sulphate anions were observed. In addition, in order to provide parallels to solvent extraction, the extracted Ni(ii) complex with HDNNS and 4PC is also prepared and studied using FT-IR and ESI-MS technology. Compared with their corresponding free ligand, similar shifts assigned to the stretching vibration of the pyridine ring and S=O in both the nickel synergist complex and the extracted Ni(ii) complex suggest that in the non-polar organic phase, Ni(ii) is also coordinated by LII ligands, while the sulfonic oxygen atoms of dinonylnaphthalene sulfonate anions not directly bonded to Ni(ii) form hydrogen bonds with water molecules (coordinated with Ni(ii) or/and solubilized in the non-polar organic phase). For the ESI-MS spectrum of the extracted Ni(ii) complex in non-polar organic phase, there exists a peak at m/z values of 1058.76, which indicates that the extracted Ni(ii) complex in the non-polar organic phase may have a coordination structure, [Ni(H2O)4(LII)2](DNNS)2, similar to the coordination structure of the nickel synergist complex. [ABSTRACT FROM AUTHOR]