Search

This work reports the development of a novel microfluidic biosensor using a graphene field-effect transistor (GFET) design for the parallel label-free analysis of multiple biomarkers. Overcoming the persistent challenge of constructing μm2-sized FET sensitive interfaces that incorporate multiple receptors, we implement a split-float-gate structure that enables the manipulation of multiplexed biochemical functionalization using microfluidic channels. Immunoaffinity biosensing experiments are conducted using the mixture samples containing three liver cancer biomarkers, carcinoembryonic antigen (CEA), α-fetoprotein (AFP), and parathyroid hormone (PTH). The results demonstrate the capability of our label-free biochip to quantitatively detect multiple target biomarkers simultaneously by observing the kinetics in 10 minutes, with the detection limit levels in the nanomolar range. This microfluidic biosensor provides a valuable analytical tool for rapid multi-target biosensing, which can be potentially utilized for domiciliary tests of cancer screening and prognosis, obviating the need for sophisticated instruments and professional operations in hospitals. [ABSTRACT FROM AUTHOR]

The precise design and development of high-performing oxygen evolution reaction (OER) for the production of industrial hydrogen gas through water electrolysis has been a widely studied topic. A profound understanding of the nature of electrocatalytic processes reveals that Ni-based catalysts are highly active toward OER that can stably operate at a high current density for a long period of time. Given the current gap between research and applications in industrial water electrolysis, we have completed a systematic review by constructively discussing the recent progress of Ni-based catalysts for electrocatalytic OER at a large current density, with special focus on the morphology and composition regulation of Ni-based electrocatalysts for achieving extraordinary OER performance. This review will facilitate future research toward rationally designing next-generation OER electrocatalysts that can meet industrial demands, thereby promoting new sustainable solutions for energy shortage and environment issues. [ABSTRACT FROM AUTHOR]

Fluorescent carbon quantum dots (CQDs) were synthesized from cucurbit[7]uril (Q[7]) and 2,2-bis(hydroxymethyl)propionic (DMPA) by a hydrothermal method. The Q[7]–DMPA complex was confirmed by X-ray crystallography. The CQDs showed blue fluorescence, photostability, and ionic strength stability. They were used to detect histamine with a low limit of 2.33 × 10−6 M. [ABSTRACT FROM AUTHOR]

Limited by single metal active sites and low electrical conductivity, designing nickel-based metal–organic framework (MOF) materials with high activity and durability remains a challenge. Here, a novel class of two-dimensional trimetallic MOF nanosheets with plentiful active sites, rich metal defects, and facilitated mass and electron transfer channels is developed as efficient electrocatalysts for boosting oxygen evolution reaction (OER). The unique 2D nanosheet structure enlarges the active area; meanwhile, the organic ligand in the MOF can work as a pillar to enlarge the interplanar space to boost the ion and electron transportation, and the synergistic effect between multi-metal active sites can effectively promote the electrocatalytic activity. Interestingly, after an electrochemical activation process, the optimized NiFeZn MOF nanosheets can yield abundant metal defects, enabling them to deliver a low overpotential of 233 mV at 10 mA cm−2 with a much smaller Tafel slope of 37.8 mV dec−1. More importantly, this method is also universal for the synthesis of the NiFe-MOF family for achieving outstanding electrocatalytic OER performance. These findings present a universal strategy for the construction of a novel class of 2D trimetallic MOF nanosheets for the OER. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) are considered the promising next-generation advanced energy storage devices. It is very important to quickly screen out ideal anode materials for LIBs with excellent performance. In this work, an effective procedure is designed for the high-throughput screening of the three kinds of LIB anode materials from 131 613 inorganic compounds in the Materials Project database. The high throughput screen procedure was not only reliable but was also easily realized. Three ideal anode materials were obtained by considering remarkable thermodynamic stability, Li capacity larger than 372 mA h g−1, band gap smaller than 1.0 eV, and two-dimensional constraint. Furthermore, open-circuit voltage, volume expansion ratio, and the diffusion energy barrier were calculated by the DFT-D corrected density functional method. We believe that our high throughput screen procedure can effectively and accurately search for other kinds of anode materials, which can strongly support the theoretical basis for experimental research. [ABSTRACT FROM AUTHOR]

A receptor-targeting AIE photosensitizer (CE-TPA) is synthesized by conjugating cephalothin with a cationic D–A type AIE photosensitizer for selective killing of Gram-positive bacteria over Gram-negative bacteria and normal mammalian cells. By virtue of the strong photosensitization capability, CE-TPA exhibits efficient killing against Gram-positive methicillin-resistant Staphylococcus aureus. More importantly, the photodynamic bactericidal outcome can be conveniently reflected in a real-time fashion by the polarity-sensitive property of CE-TPA. [ABSTRACT FROM AUTHOR]

Several aggregation-induced emission luminogens (AIEgens) with excellent water-solubility and near-infrared emission were designed and synthesized for wash-free "off–on" mitochondrial imaging and photodynamic therapy of HeLa cells. The AIEgen TEPP exhibits both bright near-infrared emission (ϕF = 17.8%) and high hybrid ROS productivity (including OH˙ and 1O2). [ABSTRACT FROM AUTHOR]

A novel viscosity probe (NV1) was developed for assessing cancer cell migration. NV1 can respond to changes of viscosity rapidly and exhibits high sensitivity in HepG2 cells treated with starvation, rotenone and nystatin. Importantly, NV1 was used for the first time to evaluate the relationship between intracellular viscosity changes and cancer cell migration and proved that increased intracellular viscosity inhibits cell migration while decreased intracellular viscosity promotes cell migration. [ABSTRACT FROM AUTHOR]

Electrocatalytic reduction of biomass-derived furan compounds provides a green and sustainable approach to produce value-added fuels and chemicals. Despite the achievements in unimolecular transformation, C–C coupling which holds great promise to yield precursors for high-density fuels has not received extensive attention. Herein, we report a Cu2O-derived nanowire array material with switchable selectivity to electrocatalytic reduction of furfural depending on the electrolyte pH. Besides a high selectivity of 98.4% to furfuryl alcohol via hydrogenation at pH 9.5, the Cu2O-derived array structure also exhibits a high selectivity of 83.5% to hydrofuroin via C–C coupling at pH 14. Upon control experiments and detailed characterization of the electrodes, the array architecture is proposed to decrease the diffusion of ketyl radicals which are the key intermediates for C–C coupling. The confined diffusion results in a high local concentration of the radicals in the array and facilitates their collision for enhancing the formation of hydrofuroin. [ABSTRACT FROM AUTHOR]

With the aim of gaining new insight into the underlying apoptosis mechanisms and in vivo efficacy of cyclometalated Ir(III) complexes as metalodrugs, six new cyclometalated Ir(III)–quinoline complexes, [Ir(1a)(2pq)2] (2a), [Ir(1b)(2pq)2] (2b), [Ir(1c)(2pq)2] (2c), [Ir(1d)(2pq)2] (2d), [Ir(1e)(2pq)2] (2e), and [Ir(1f)(2pq)2] (2f) (2pq = 2-phenylisoquinoline), have been synthesized using 5,7-dihalo-8-hydroxylquinoline ligands (1a–1f) and [Ir(2pq)2Cl]2 precursors and characterized. Complexes 2a–2f have shown potent anticancer activity against cisplatin-resistant SK-OV-3/DDP and A549/DDP cells (IC50 = 0.11–1.83 μM), following the order 2e > 2f > 2b > 2c > 2d > 2a. Confocal microscopy images suggest that 2e and 2b could act as red-color probes for specific cell imaging and efficiently initiate apoptosis and autophagy in the mitochondria, cell cytosol, and nucleus. Overexpression of beclin1, caspase-9, cytochrome c, LC3II, and apaf-1; inhibition of p62, cyclin D1, cyclin A2, and CDK2; and a substantial rapid accumulation suggest a paraptotic mode of cell death induced by autophagy, DNA damage, and mitochondrial stress. In addition, the inhibitory rate of 2e on A549/DDP tumor growth was 64.1% at a concentration of 10.0 mg kg−1, which is clearly higher than that of cisplatin. According to the biological assay, the cyclometalated Ir(III)–quinoline complex 2e exhibited a higher anticancer effect than 2b, which may be associated with the electronic effect of the methyl group of the 1e ligand of 2e playing a key role in the mechanism. [ABSTRACT FROM AUTHOR]

Herein, to reduce the platinum usage and increase the efficiency of noble metals in the catalysis of the oxygen reduction reaction, Ag was used as an assistant reductant, support and sacrificial template to prepare a low-platinum PtAg/C catalyst through a gradual reduction method with the final Pt mass percentage of 10.86 wt%. This as-synthesized low-platinum PtAg/C catalyst exhibited excellent oxygen reduction reaction activity and durability in an acid. With only 54.77% Pt usage, the half-wave potential of PtAg/C is 28 mV higher than that of commercial Pt/C and its limited diffusion current density is 1.1 times that of Pt/C. Furthermore, its electrochemically active surface area is 2.28 times higher than that of commercial Pt/C. Also, its area-specific activity and mass activity are approximately 1.85 and 4.22 times that of Pt/C, respectively. The PtAg/C catalyst displayed extraordinary ORR performance with higher limited current density and half-wave potential than commercial Pt/C after 10 000 potential cycles in HClO4. Thus, PtAg/C is more active and stable for ORR catalysis in acid. [ABSTRACT FROM AUTHOR]

A facile solvent diffusion method was developed to prepare phospholipid–amorphous calcium carbonate (ACC) hybrid nanoparticles via a one-pot approach. The hybrid nanoparticles can specifically realize water-responsive burst drug release in cancer cells and potentiate drug penetration into deep tumor tissues for advanced cancer therapy. [ABSTRACT FROM AUTHOR]

In this study, we have identified 5-HMF and two additional derivatives (II and III) in glucose i.v. solution and reported normal phase high performance liquid chromatography for the first time for simultaneous determination of these three compounds. Chromatographic separation was achieved in less than 10 min on a Platisil Silica column at 30 °C with n-hexane/methanol/dichloromethane (70/24/6, v/v/v) as the mobile phase at a flow rate of 1.0 mL min−1 at 284 nm, and the methodology results were all in accordance with the guidelines. Using this established method, 15 different batches of glucose i.v. solutions were tested. Not only did the concentrations of 5-HMF detected by this method coincide with the results by the UV method adopted by pharmacopeias of various countries, but our proposed method could also reflect the types and contents of compounds I–III in glucose injection. A conversion study revealed that compounds I–III were labile and interconverted under various conditions, especially in saline and weak acidic solutions, which were similar to the routine application of glucose i.v. solution for patients. All the results indicated the useful application of this study for the quality control of glucose solution. [ABSTRACT FROM AUTHOR]

This work reports new annulations of N-aryl ynamides with benzisoxazoles to form 6H-indolo[2,3-b]quinoline derivatives. The synthetic utility of this new method is manifested by its applicability to access naturally occurring alkaloids including norcryptotackeine, neocryptolepine and 11-methylneocryptol-epine. Our experimental data indicate that high-temperature conditions allow N-aryl nucleophiles to become conformationally flexible, rendering the attack at gold carbenes effective to generate reactive indoles that attack again the benzaldehyde to furnish the observed products. [ABSTRACT FROM AUTHOR]

We report alkaline earth metal ion-mediated solid photoluminescent complexes of thioflavin T (ThT) with twisted cucurbit[14]uril (tQ[14]) for the first time. The interaction with tQ[14] enhanced the fluorescence of ThT in aqueous solution. Indeed, the fluorescence intensity of ThT increased rapidly with increasing amount of tQ[14] up to a tQ[14] : ThT ratio of 15. Interestingly, at lower tQ[14] : ThT ratios (1 : 1), the introduction of alkaline earth metal cations (AE2+) into the tQ[14]–ThT interaction system led to fluorescence quenching of ThT, except in the case of Mg2+ cation, which led to an initial fluorescence enhancement, followed by gradual fluorescence quenching of ThT. At higher tQ[14] : ThT ratios (1 : 15), the introduction of alkaline earth metal cations into the tQ[14]–ThT interaction system led to the precipitation of solid tQ[14]/ThT/AE2+ interaction products, which emitted strong blue fluorescence, except in the case of Sr2+ cation, which exhibited fluorescence quenching of ThT without any solid precipitation. Thus, the tQ[14]–ThT interaction system shows potential applications not only for preparing stimuli-responsive supramolecular photoluminescent materials, but also for identifying Mg2+ at lower tQ[14] : ThT ratios and Sr2+ at higher tQ[14] : ThT ratios. [ABSTRACT FROM AUTHOR]

Metal coordination crosslinking between stiff N-polyindole chains was constructed, and the crosslinked films exhibited high tensile strength, high heat resistance and excellent polar solvent resistance. The noncovalent crosslinking can be further removed via external pyrophosphate, which endows the crosslinked polymer with a recyclable behavior. The tensile strength and glass transition temperature of the polymers can be nondestructively detected by taking advantage of the fluorescence quenching effect of metal coordination to the adjacent bipyridine structure. [ABSTRACT FROM AUTHOR]

SiO2@HMF hybrid particles were obtained by the surface-modification of silica gel using 5-hydroxymethylfurfural, a platform chemical with various bioactivities, and silane coupling agents as a linker. The materials were confirmed by IR, elemental analysis and XPS. The retention time of bovine serum albumin on SiO2@HMF as a stationary phase was prolonged as compared to that of SiO2. The results may provide a new idea for the separation and recognition of proteins. [ABSTRACT FROM AUTHOR]

Aryl homocoupling reactions via meta- and ortho-selective C–H activation have been achieved on surfaces, but the highly important para-selective C–H activation has not been reported yet. Combined with scanning tunneling microscopy, time-of-flight secondary ion mass spectrometry and density functional theory, here we describe dehydrogenative homocoupling of tetrafluorobenzene on Pd(111) via para-selective C–H activation to form perfluorinated oligo(p-phenylene)s. [ABSTRACT FROM AUTHOR]

A new copper-facilitated oxidative cyclization of 2-allenyl-1,1′-biphenyls with α-carbonyl alkyl bromides for producing functionalized phenanthrenes is presented, which represents the first allene 2,3-dicarbofunctionalization triggered by oxidative radical-medicated C3-addition of the terminal allene moiety and C–Br/C–H functionalization. [ABSTRACT FROM AUTHOR]

A novel copper-promoted [2+2+2] annulation of 1,n-enynes with azobis(alkyl nitrile)s and H2O for the synthesis of diverse 7,8-dihydrophenanthridine-6,9(5H,6aH)-diones and fluorene is described. The reaction proceeds via the decomposition of azobis(alkyl nitrile)s into the cyanoalkyl radicals as the two-carbon units and offers a new efficient tool for the one-step formation of four new chemical bonds. [ABSTRACT FROM AUTHOR]

Flexible gate-opening metal organic frameworks (GO-MOFs) expand or contract to minimize the overall free energy of the system upon accommodation of an adsorbate. The thermodynamics of the GO process are well described by a number of models, but the kinetics of the process are relatively unexplored. A flexible GO-MOF, RPM3-Zn, exhibits a significant induction period for opening by N2 and Ar at low temperatures, both above and below the GO pressure. A similar induction period is not observed for H2 or O2 at comparable pressures and temperatures, suggesting the rate of opening is strongly influenced by the gas-surface interaction rather than an external stress. The induction period leads to severe mass transfer limitations for adsorption and over-prediction of the gate-opening pressure. After review of a number of existing adsorption rate models, we find that none adequately describe the experimental rate data and similar timescales for diffusion and opening invalidate prior reaction-diffusion models. Statistically, the rate data are best described by a compressed exponential function. The resulting fitted parameters exceed the expectations for adsorption but fall within those expected for phase transition. By treating adsorption as a phase transition, we generalize the Avrami theory of phase transition kinetics to describe adsorption in both rigid and flexible hosts. The generalized theory is consistent with observed experimental trends relating to induction period, temperature, pressure, and gas-substrate interaction. [ABSTRACT FROM AUTHOR]

A solution-processed organometallic halide perovskite-based bulk heterojunction (BHJ) memory device with a configuration of indium-doped tin oxide (ITO)/CH3NH3PbI3:PVK/Al has been successfully fabricated. Under a threshold voltage of −1.57 V, this device shows a nonvolatile write-once read-many-times (WORM) memory effect, with a maximum ON/OFF current ratio exceeding 103. In contrast, the ITO/CH3NH3PbI3/Al device showed only conductor characteristics, while the PVK-based device exhibited insulator behavior. Upon being subjected to voltages, an interesting filamentary nature of the CH3NH3PbI3:PVK film was also observed in situ at the microscopic nanometer level using a conductive atomic force microscopy (C-AFM) technique with a device configuration of Si/Pt/CH3NH3PbI3:PVK/Pt. The mechanism associated with the memory effect is discussed. The electric-field-induced intermolecular charge transfer effect between CH3NH3PbI3 and PVK, and the possible conformational ordering of the PVK side-chains/backbone under an applied bias voltage, may cause the electrical conductivity switching and WORM effect in the reported BHJ device. [ABSTRACT FROM AUTHOR]

Pseudo-allergic reactions are non-IgE-mediated immediate allergic reactions, and MRGPRX2 is a potential important target for pseudo-allergic reactions. Currently, numerous reports focus on the induction of pseudo-allergic reactions by small molecule drugs and endogenous peptides. However, insufficient attention has been paid to the pseudo-allergic reactions induced by exogenous peptides through MRGPRX2. Therefore, this study selected immunogenic peptide composition HL-9-5, which has a structure and properties similar to substance P, and its analogue HL-9-4. We conducted experiments through LAD2 cell β-hexosaminidase release, histamine release, cytokine release and MRGPRX2-HEK293 cell calcium mobilization assay in vitro, and mice paw swelling, serum histamine detection, hindpaw skin H&E and TB staining in vivo demonstrated that HL-9-4 and HL-9-5 can trigger pseudo-allergic reactions via MRGPRX2. Molecular docking further showed that SP, HL-9-4 and HL-9-5 can act on the same cavity in MRGPRX2, and ASP-174 was identified as the conserved site of interaction for all three compounds. Therefore, HL-9-4 and HL-9-5 are exogenous analogues of substance P that can induce pseudo-allergic reactions. This study laid the foundation for research on the mechanism of pseudo-allergic reactions induced by exogenous peptide compounds and was also of great significance for subsequent research on the interaction between various ligands and MRGPRX2 and for the development of peptide antagonists. [ABSTRACT FROM AUTHOR]

Correction for 'Facile preparation of phospholipid–amorphous calcium carbonate hybrid nanoparticles: toward controllable burst drug release and enhanced tumor penetration' by Cheng Wang et al., Chem. Commun., 2018, 54, 13080–13083, DOI: 10.1039/C8CC07694D. [ABSTRACT FROM AUTHOR]

(di-)Thioacetals and (di-)thioketals serve commonly as protecting groups of carbonyls and alcohols in organic synthesis, and therefore require highly efficient and chemoselective methods for desulfurization into carbonyls or alcohols. Although many approaches have been developed for such deprotection reactions, they usually employ toxic and/or expensive reagents under harsh conditions with a relatively long reaction time. Reported is a green catalytic approach that exploits Fenton-like chemistry (FLC: CeBr3–H2O2) for the oxidative desulfurization of thioacetals and thioketals, which has many competitive advantages including (1) high efficiency (15 min, up to 97% yield), (2) high chemoselectivity with broad substrate scope, (3) greenness (H2O as the sole waste) with outstanding green chemistry metrics, and (4) low cost. Detailed mechanistic studies revealed that the reactive brominating species (RBS, HOBr) generated in situ using Fenton-like chemistry (i.e., HO˙) and bromide reacted with sulfide (thioacetals or thioketals) to form the bromosulfonium intermediate (RR'S-Br), which was attacked by a heteroatom such as sulfur, oxygen or nitrogen to initiate the hydrolysis to carbonyls or alcohols. The released bromide ion (Br−) could be oxidized again by Fenton-like chemistry to generate RBS for the next catalytic cycle. This highly efficient, chemoselective, and green approach for oxidative desulfurization is expected to find wide applications in organic synthesis. [ABSTRACT FROM AUTHOR]

Copper ions (Cu2+) play an essential role in various cellular functions, including respiration, nerve conduction, tissue maturation, oxidative stress defense, and iron metabolism. Covalent organic frameworks (COFs) are a class of porous crystalline materials with directed structural designability and high stability due to the combination of different monomers through covalent bonds. In this study, we synthesized a porphyrin-tetrathiazole COF (TT-COF(Zn)) with Zn-porphyrin and tetrathiafulvalene (TTF) as monomers and used it as a photoactive material. The strong light absorption of metalloporphyrin and the electron-rich properties of supplied TTF contribute to its photoelectrochemical performance. Additionally, the sulfur (S) in the TTF can coordinate with Cu2+. Based on these properties, we constructed a highly sensitive photoelectrochemical sensor for detecting Cu2+. The sensor exhibited a linear range from 0.5 nM to 500 nM (R2 = 0.9983) and a detection limit of 0.15 nM for Cu2+. Notably, the sensor performed well when detecting Cu2+ in water samples. [ABSTRACT FROM AUTHOR]

A high-efficiency sulfur host with bimetallic oxide CuCo2O4 cubes supported on carbon cloth has been designed and used in lithium sulfur batteries, which can suppress the "shuttle effect" and boost the redox reaction kinetics. The unique three-dimensional cube-based structure realized a high sulfur loading of 7.1 mg cm−2, and the corresponding assembled lithium sulfur battery delivered excellent cycling stability over 100 cycles at 0.1C. [ABSTRACT FROM AUTHOR]

The lithium (Li) metal anode is an intriguing choice for Li metal batteries because of its considerably high theoretical capacity. However, the commercialization of unimproved lithium metal batteries is impeded due to the severe security issues related to uncontrollable Li dendrite growth. Herein, we fabricated three-dimensional (3D) mullite sheets via a high temperature annealing process in the presence of silica sol and used such sheets as interlayers between Li anodes and separators for assembling cells. As both Al2O3 and SiO2, the two main components of mullite fibers, are lithiophilic, the deposition of Li during charging processes could be regulated and the growth of lithium dendrites and accumulation of dead Li could be efficiently suppressed. In a Li‖‖Cu half-cell, the mullite fiber/Li composite electrode delivers a coulombic efficiency of above 98% under a current density of 1.0 mA cm−2. For a Li‖‖LiFePO4 full cell, the same composite electrode exhibited improved capacity retention (>89%, after 800 cycles) and rate capability at 5.0C. [ABSTRACT FROM AUTHOR]

DTBP (di-tert-butyl peroxide) is utilized to mediate oxidative 1,2-difunctionalization of activated alkenes with an aryl C(sp2)–H bond and a benzylic C(sp3)–H bond for the synthesis of functionalized oxindoles. This reaction is a new organomediated strategy for alkene difunctionalization facilitated by Lewis acids. [ABSTRACT FROM AUTHOR]

In recent years, two-dimensional transition metal dihalides have emerged as a subject of growing research interest in the field of gas sensing. This heightened attention can be attributed to their notable characteristics of high surface area ratios, customizable electronic properties of the layers, and a wide range of catalytic capabilities. These unique features make them promising candidates for gas sensing applications and warrant further investigation and exploration in this area. Practical applications of the original TMD (MoS2) gas sensors are limited by their poor gas sensing performance at room temperature (RT), including less-than-full recovery, long response times, and low response speeds. Addressing these challenges is crucial for improving their real-world usability. In this study, we synthesized three-component heterojunctions (Co3O4–CoS2@MoS2) with a controlled morphology and composition using different mass ratios of raw materials. The Co3O4–CoS2@MoS2-2 gas sensor demonstrated exceptional sensitivity to NO2 gas (Ra/Rg = 39.6 in 100 ppm) at room temperature, achieving an ultra-fast response time of merely 3.4 seconds in ambient air. This sensing behavior first benefits from Co3O4's high specific surface area and abundant oxygen vacancy concentration. The second is the synergistic effect of the heterogeneous structure between MoS2 and Co3O4. And finally, the electron holding capacity of the S atom in CoS2. The synergistic effect of the three factors promotes the gas-sensing performance of the sensor. The results we obtained show that this approach is viable to improve the sensing performance of metal oxides under RT conditions and can also be scaled up to include other 2D transition metal dihalide-based materials. [ABSTRACT FROM AUTHOR]

Artificial synthesis of carbohydrates has been a long-standing goal for chemists. The formose reaction is an established non-enzymatic one-step route to monosaccharides from a C1 source, where formaldehyde (HCHO) is polymerized under basic conditions. However, bases can lead to multiple side reactions. Thiazolium salts, when activated by a suitable base, can catalyze HCHO condensation to 1,3-dihydroxyacetone (DHA) via umpolung aldehyde activation, but they can slowly lose their activity due to product adsorption on the active sites. Here, we report a heterogeneous, base-free formaldehyde condensation to DHA using a reactor based on a Soxhlet extractor, which quickly separates the product from the solid catalyst during the reaction. This design not only leads to a stable catalytic operation but also constitutes a clean HCHO-to-DHA conversion system. This oligomerization of formaldehyde to DHA completes a critical step in converting CO2 to sugar, including CO2 hydrogenation to methanol (CH3OH), CH3OH oxidation to HCHO, HCHO oligomerization to DHA, and DHA condensation to higher carbohydrates. [ABSTRACT FROM AUTHOR]

A three-dimensional lithiophilic electrospun nanofiber framework with a Ag nanowires/polyvinylpyrrolidone (AgNWs/PVP) hybrid as a multifunctional interlayer has been designed to protect lithium metal anodes. The full cells with a LiFePO4 cathode and AgNWs/PVP interlayer have also realized excellent stable cyclability over 1000 cycles and high-rate capability. [ABSTRACT FROM AUTHOR]

The synthesis of furan-based platform chemicals from abundant and renewable biomass-based hexoses plays an important role in the development and utilization of biomass energy. The electrochemical 5-hydroxymethylfurfural oxidation reaction (HMFOR) represents a promising route for synthesizing the 2,5-furandicarboxylic acid (FDCA) product which is a high value-added biomass-based monomer. Interface engineering is an effective strategy to adjust the electronic structure, optimize the adsorption of intermediates, and expose more active sites, thus attracting extensive attention for designing efficient HMFOR electrocatalysts. Herein, a NiO/CeO2@NF heterostructure with an abundant interface is designed for boosting the HMFOR performance under alkaline conditions. At 1.475 V vs. RHE, the conversion of HMF is nearly 100%, the selectivity of FDCA is 99.0%, and the faradaic efficiency is as high as 98.96%. The NiO/CeO2@NF electrocatalyst also exhibits robust stability for HMFOR for 10 cycles. When coupled with the cathode hydrogen evolution reaction (HER) in alkaline medium, the yields of FDCA and hydrogen production are 197.92 and 600 μmol cm−2 h−1, respectively. The NiO/CeO2@NF catalyst is also suitable for the electrocatalytic oxidation of other biomass-derived platform compounds. The abundant interface between NiO and CeO2, which can regulate the electronic properties of Ce and Ni atoms, improve the oxidation state of Ni species, regulate intermediate adsorption, and promote electron/charge transfer, makes the most contribution to high HMFOR performance. This work will provide a simple route for the design of heterostructured materials and reveal the application prospect of interface engineering for promoting the upgrading of biomass derivatives. [ABSTRACT FROM AUTHOR]

Metal–organic layers (MOLs) are versatile platforms for creating single-site heterogeneous catalysts. Incorporating molecular functionalities into MOLs is crucial for catalysis. In this study, we synthesized phosphine-containing MOLs constructed from Hf6-oxo secondary building units (SBUs) and phosphine ligands. The mono(phosphine)-Ir complexes generated by the metalation of TPP-MOL were highly active as heterogeneous catalysts for the C(sp2)–H borylation of a range of arenes. This research expands the diversity of MOL-based catalysts. [ABSTRACT FROM AUTHOR]

Metal NP @ metal–organic frameworks (MOFs) are widely used in electrocatalysis. However, many of the MOFs are poorly conductive. Here, we loaded bismuth (Bi) into a Zr-based MOF of the UiO structure that is active for CO2 reduction to formate and found that a moderate conductivity of the nanosized MOFs is sufficient to support a reasonably high catalytic current density. This finding allows simpler catalyst design and quantitative rationalization of MOF electrocatalysis. [ABSTRACT FROM AUTHOR]

Diverse self-assembled structures were obtained on Cu(111) and Ag(111) surfaces by using a simple and small 4,4′′-dichloro-1,1′:4′,1′′-terphenyl molecule. Surprisingly, a complicated supramolecular self-assembled vortex structure, composed of 15 molecules in a large unit, was realized through the collaboration of hydrogen bonding and halogen bonding. [ABSTRACT FROM AUTHOR]

We have successfully constructed a new type of recyclable indole-based hydrogel, which exhibited highly effective extraction behavior for hydroxide via the synergistic effect of cation–π interactions and hydrogen bonds. More interestingly, the absorption performance could be visually detected by taking advantage of the color altering effect of the host–guest interactions. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), is a highly infectious disease with a significant impact on global public health security, and the development of effective antiviral drugs is warranted. In this study, based on HEK293 membrane chromatography (CMC) model that overexpresses angiotensin-converting enzyme 2 (ACE2), we screened six compounds with long retention time on ACE2h/CMC, namely BU-1 to BU-6, from the biphenyl furanocoumarin compounds previously synthesized by our team. The binding properties of the screened compounds to ACE2 were investigated by frontier analysis. Cytotoxicity assay, virtual molecular docking assay and pseudo-viral invasion assay were used to examine the affinity and potential antiviral activity of the selected compounds towards ACE2 protein. The virtual molecular docking results showed that BU-1, BU-2 and BU-5 could form significant hydrogen bonds with hotspot amino acid residues on the ACE2 receptor. And BU-1, BU-2 and BU-5 significantly inhibited the ability of SARS-COV-2 pseudovirus to enter ACE2h cells. Therefore, BU-1, BU-2 and BU-5 have the potential to be used as lead compounds for further modification to develop more effective anti-SARS-CoV-2 drugs. [ABSTRACT FROM AUTHOR]

By the strategy of equipping a fluorophore with two reaction triggers that are tailored to the specific chemistry of peroxynitrite, we have developed a highly selective probe for detecting peroxynitrite in live cells. Sequential response by the two triggers enabled the probe to reveal various degrees of nitrosative stress in live cells via a sensitive emission colour change. [ABSTRACT FROM AUTHOR]

This communication reports on a fluorescent probe (PPI-P) for imaging active peptidyl-prolyl cis/trans isomerases in live cells. PPI-P is capable of responding to both recombinant and cellular PPIases fluorogenically, and has been shown to specifically image active PPIases in live cells. [ABSTRACT FROM AUTHOR]

Ag nanocrystals with branched structures have attracted broad interest due to their application in surface enhanced Raman scattering (SERS) and catalysis. Herein, we reported the synthesis of two-dimensional Ag nanoplates with highly branched structures via a seed-mediated method. Systematic studies on controlled kinetic growth were carried out to elucidate the growth mechanism. It was found that such nanostructures could be achieved when the atomic deposition rate was much larger than the surface diffusion rate of Ag atoms on the nanoplates, which was fulfilled by the incorporation of Cu in the Ag lattice through Cu-UPD. The as-prepared branched Ag nanoplates exhibited superior performance towards the catalytic reduction of nitrophenol. [ABSTRACT FROM AUTHOR]

TiO2 is one of the most promising anode materials for lithium ion batteries (LIBs) due to its safe working potentials and small volume changes during lithium insertion/extraction. However, its inherently poor electronic and ionic conductivities have restricted its practical applications. Herein, well-defined TiO2 nanocrystals were prepared from an atomically precise titanium-oxo cluster (Ti8Ph) and then coupled with carbon layers and graphene nanosheets. When used as anode materials for LIBs, the TiO2-C-rGO composite delivered a high capacity of 834 mA h g−1 at 0.1 A g−1 after 300 cycles and 398 mA h g−1 at 5.0 A g−1 after 600 cycles, which are far superior to those of the control samples (TiO2-C, TiO2-rGO and TiO2) and most other reported TiO2-based nanostructures. The exposed facets of TiO2 nanocrystals were favorable for lithium diffusion and the carbon coupling was beneficial for the electron transfer. The latter also enhanced the structural robustness and hence the cycling stability of the composite. Moreover, the abundant three-phase interfaces between the carbon species and the TiO2 nanocrystals endowed the material with rich adsorption sites and substantially boosted pseudo-capacitive lithium storage. This work offered an alternative route to rationally design versatile nanostructures from clusters and contributed to the development of high-efficiency energy materials. [ABSTRACT FROM AUTHOR]

Oxidation states of Sn in tin oxides are hard to regulate due to the uncontrollable evolution during the electrochemical CO2 reduction reaction (CO2RR), thus limiting the adsorption capabilities and reaction kinetics. Herein, we propose a metal oxide–support interaction-mediated strategy to modify the electronic properties of tin oxides. A gradient Sn4+@Sn2+ core@shell structure was formed as a result of electron transfer from g-C3N4 to anchored SnO2, unlike reduced graphene oxide (rGO)-supported SnO2 with Sn4+-rich surfaces. Such unique structures were revealed by the depth profiles of X-ray photoelectron spectra, and they enhanced the adsorption and stabilization of the *CO2˙− intermediate and accelerated the reaction kinetics. Consequently, SnO2/g-C3N4 delivered a faradaic efficiency of 95.1% for the C1 products at −1.06 V, exceeding those of SnO2/rGO and most reported catalysts. Moreover, the performances were sustained for 70 h without obvious degradation. This work offers an alternative route to efficient catalyst design by combining oxidation state regulation and metal oxide–support interaction and contributes to the development of sustainable technologies for achieving carbon neutrality. [ABSTRACT FROM AUTHOR]

Electrocatalytic nitrate reduction offers a sustainable route to ammonia synthesis and wastewater treatment. However, the nitrate-to-ammonia conversion remains inefficient due to the sluggish kinetics and diverse side reactions. Herein, well-faceted CuNi nanocrystals with Ni-rich surfaces and favorable d-band centres were synthesized with the assistance of γ-cyclodextrin via a solvothermal process. When used as catalysts for nitrate electroreduction, they delivered an ammonia yield of 1.374 mmol h−1 mg−1 (0.5496 mmol h−1 cm−2) at −0.3 V with the faradaic efficiency and selectivity reaching 94.5% and 65.0%, respectively, surpassing pure Cu or Ni nanocrystals and most reported catalysts. Such excellent performances originated from the optimal geometric and electronic structures and special element distribution, which optimized the adsorption behaviors and accelerated the reaction kinetics. A NO3−–NO2−–NH3 pathway was proposed with the chemical process following the initial electron transfer process as the rate-determining step. This work sheds light on the design of efficient catalysts to achieve carbon neutrality through simultaneous geometric and electronic structure modulation. [ABSTRACT FROM AUTHOR]

Optimization of glycosylation conditions for automated glycan assembly is highly challenging, demands wasteful use of precious building blocks, and relies on nontrivial analyses. We developed a semi-quantitative method for automated optimization of glycosylation temperature that utilized minute quantities of donors and translated those conditions to solid-phase glycan assembly. [ABSTRACT FROM AUTHOR]

Metal–organic layers (MOLs), a category of two-dimensional materials, have attracted wide interest due to their molecular tunability and the ease of surface modification. Herein, we reported the synthesis and structural determination of a free-standing MOL, {[Hf6O8H4(HCOO)2(H2O·OH)4]3[Hf12O16H8(HCOO)6.8(H2O·OH)11.2](TPO)8}n, constructed from Hf6-oxo and Hf12-oxo clusters as secondary building units (SBUs) and the tris(4-carboxylphenyl)phosphine oxide (TPO) ligand. We establish a structure model of this new MOL based on the combined information from different characterization methods. [ABSTRACT FROM AUTHOR]

Accurate separation of microparticles by shape has diverse applications in biology and biotechnology, but is a significant challenge in separation science and engineering. We demonstrate a simple and effective mechanism that can achieve shape-based separation of magnetic particles in microscale flows. In this method, a uniform magnetic field is applied perpendicularly to the flow direction, and causes shape-dependent lateral migration of the particles. Using high-speed imaging, we studied the rotational dynamics of the ellipsoidal particles. It is found that the lateral migration is correlated with the asymmetric rotation of the particles. Different from existing techniques that use magnetic forces, our method uses shape-dependent magnetic torque but zero magnetic force. [ABSTRACT FROM AUTHOR]

As part of the body's immune response, antibodies (Abs) have the ability to neutralize pathogenic viruses to prevent infection. To screen for neutralizing Abs (nAbs) from the immune repertoire, multiple screening techniques have been developed. However, conventional methods have a trade-off between screening throughput and the ability to screen for nAbs via their functional efficacy. Although droplet microfluidic platforms have the ability to bridge this disparity, the majority of such reported platforms still rely on Ab-binding assays as a proxy for function, which results in irrelevant hits. Herein, we report the multi-module Droplet-based Platform for Effective Antibody RetrievaL (DROP-PEARL) platform, which can achieve high-throughput enrichment of Ab-secreting cells (ASCs) based on the neutralizing activity of secreted nAbs against the a target virus. In this study, in-droplet Chikungunya virus (CHIKV) infection of host cells and neutralization was demonstrated via sequential delivery of viruses and host cells via picoinjection. In addition, we demonstrate the ability of the sorting system to accurately discriminate and isolate uninfected droplets from a mixed population of droplets at a rate of 150 000 cells per hour. As a proof of concept, a single-cell neutralization assay was performed on two populations of cells (nAb-producing and non-Ab producing cells), and up to 2.75-fold enrichment of ASCs was demonstrated. Finally, we demonstrated that DROP-PEARL is able to achieve similar enrichment for low frequency (∼2%) functional nAb-producing cells in a background of excess cells secreting irrelevant antibodies, highlighting its potential prospect as a first round enrichment platform for functional ASCs. We envision that the DROP-PEARL platform could potentially be used to accelerate the discovery of nAbs against other pathogenic viral targets, and we believe it will be a useful in the ongoing fight against biological threats. [ABSTRACT FROM AUTHOR]

Alcohols are attractive portable chemical carriers of hydrogen thanks to their reversible dehydrogenation, but the hydrogen release reaction is thermodynamically unfavorable. Coupling the alcohol dehydrogenation to acetal formation can shift the reaction thermodynamics for hydrogen production. Here, we stabilized Ir3+ and Sc3+ in a metal–organic framework (MOF) for tandem catalysis. The Ir3+ center bearing an α-hydroxybipyridine ligand catalyzes alcohol dehydrogenation, and the Sc3+ Lewis acid site catalyzes acetal formation that allows further dehydrogenation to form esters. The bifunctional UiO-bpyOH–IrCp–Sc catalyst effectively converts ethylene glycol to ester and H2 without producing CO. [ABSTRACT FROM AUTHOR]

A CO2-switchable microemulsion was fabricated by introducing low-cost commercial N,N-dimethyl-N-dodecyl amine into a sodium dodecyl sulphate–butanol–heptane solution. Upon alternate bubbling of CO2 and N2, the system reversibly switched between a monophasic microemulsion and nearly complete phase separation, reflecting the disruption and re-formation of a thermodynamically stable microemulsion. [ABSTRACT FROM AUTHOR]