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The key to the practical application of overall water splitting is to develop high‐efficient non‐noble metal electrocatalysts. Herein, carbon cloth supported N‐doped porous carbon wrapped Co nanoparticles (CC@Co‐NPC) are constructed with high bifunctional catalytic activity toward oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline medium. Benefiting from the exposure of abundant Co active sites, and the synergistic effect between Co particles and N‐doped carbon species, the CC@Co‐NPC delivers small overpotentials of 286 and 340 mV at 100 mA cm−2 with Tafel values of 59 and 97 mV dec−1 towards OER and HER, respectively. Remarkably, when coupled as CC@Co‐NPC||CC@Co‐NPC cell, only a small voltage of 1.49 V is required to achieve 10 mA cm−2, making CC@Co‐NPC a potential bifunctional catalyst for overall water splitting. [ABSTRACT FROM AUTHOR]

Siberian ginseng, perennial herb belongs to Araliaceae family used in traditional medicines to treat hypertension, thrombus, inflammation and cancer. In the present study, we biosynthesized goldnanoparticles using Siberian ginseng aqeous extract in a cost effective manner. The synthesized Siberian ginseng gold nanoparticle (SG-GNPs) were characterized using UV-Vis spec, HR-TEM, XRD, FTIR, SAED analysis. UV-Vis spectroscopic analysis showed a surface Plasmon resonance peak at 538 nm which does not reduce till 30 days of incubation. The results of HR-TEM, XRD and SAED confirm the spherical shape, crystalline nature and the size of the synthesized gold nanoparticles. The FTIR results prove that the biological components present in the Siberian ginseng had reduced the gold ions to synthesis gold nanoparticles. After characterization, the efficacy of SG-GNPS against the melanoma, a deadliest skin carcinoma, was assessed in vitro using B16 murine melanoma cells. The CC50 dose of SG-GNPs against B16 cells were assessed with MTT assay and the anticancer activity was evaluated using Rhodamine 123, H2DCFDA and dual staining techniques. The induction of apoptosis by SG-GNPs against melanoma cells were confirmed with q-PCR analysis. The results of staining techniques prove that SG-GNPs increase the reactive oxygen species and decreased the mitochondrial membrane potential. It is further confirmed by the results of q-PCR analysis which shows increased apoptotic Bid, Bad, Casp3, Casp 9 genes and decreased antiapoptotic Bcl2 gene expression in SG-GNPs treated cells. Our results authentically prove the biosynthesized SG-GNPs induces apoptosis in melanoma cells and it possesses anticancer property. [ABSTRACT FROM AUTHOR]

Abstract: The initiation of carbon nanofiber (CNF) growth on polycrystalline Ni foam was investigated by using a combination of ex situ and in situ methods, which include SEM, XRD, and Raman spectroscopy. Experiments were performed at a low hydrocarbon partial pressure to slow down the initiation process. Very little to no CNFs were observed on reduced samples, which is caused by diffusion of C to the bulk of the Ni foam. This prevents the formation of Ni3C as a precursor of Ni nanoparticles at a low hydrocarbon partial pressure from acting as active particles for CNF formation. CNF growth was significant on oxidized samples and the initiation was slowed down by using an extremely low ethylene pressure. Ni nanoparticles are able to catalyze CNF growth, provided these are isolated from the Ni bulk by unreduced NiO, which results from the incomplete reduction of the NiO layer. [ABSTRACT FROM AUTHOR]

Cell-derived microparticles (MPs) have been recently recognized as critical intercellular information conveyors. However, further understanding of their biological behavior and potential application has been hampered by the limitations of current labeling techniques. Herein, a universal donor-cell-assisted membrane biotinylation strategy was proposed for labeling MPs by skillfully utilizing the natural membrane phospholipid exchange of their donor cells. This innovative strategy conveniently led to specific, efficient, reproducible, and biocompatible quantum dot (QD) labeling of MPs, thereby reliably conferring valuable traceability on MPs. By further loading with small interference RNA, QD-labeled MPs that had inherent cell-targeting and biomolecule-conveying ability were successfully employed for combined bioimaging and tumor-targeted therapy. This study provides the first reliable and biofriendly strategy for transforming biogenic MPs into functionalized nanovectors. [ABSTRACT FROM AUTHOR]

Tin oxide (SnO2) nanomaterials are of great interest in many fields such as catalytic, electrochemical, and biomedical applications, due to their low cost, suitable stability characteristics, high photosensitivity, etc. In this contribution, SnO2 NPs were facilely fabricated by calcination of tin (II) oxalate in air, followed by a liquid-phase exfoliation (LPE) method. Size-selected SnO2 NPs were easily obtained using a liquid cascade centrifugation (LCC) technique. The as-obtained SnO2 NPs displayed strong absorption in the UV region (~300 nm) and exhibited narrower absorption characteristics with a decrease in NP size. The as-fabricated SnO2 NPs were, for the first time, directly deposited onto a poly(ethylene terephthalate) (PET) film with a regular Ag lattice to fabricate a flexible working electrode for a photoelectrochemical (PEC)-type photodetector. The results demonstrated that the SnO2-NP-based electrode showed the strongest photoresponse signal in an alkaline electrolyte compared with those in neutral and acidic electrolytes. The maximum photocurrent density reached 14.0 μA cm−2, significantly outperforming black phosphorus nanosheets and black phosphorus analogue nanomaterials such as tin (II) sulfide nanosheets and tellurene. The as-fabricated SnO2 NPs with relatively larger size had better self-powered photoresponse performance. In addition, the as-fabricated SnO2-NP-based PEC photodetector exhibited strong cycling stability for on/off switching behavior under ambient conditions. It is anticipated that SnO2 nanostructures, as building blocks, can offer diverse availabilities for high-performance self-powered optoelectronic devices to realize a carbon-neutral or carbon-free environment. [ABSTRACT FROM AUTHOR]

The effects of the orientation of a graphene sheet, the edge structure of carbon nanofibers, and different surface functional groups on proton affinity, interactions with metal nanoparticles, and electronic modification of these structures, together with their catalytic consequences, have been reviewed. The ratio of prismatic to basal sites on the edge of carbon nanofibers has a remarkable influence on the properties of both the CNFs and the metal nanoparticles that are supported on it. The proton affinity, interactions with metal particles, and electronic density of metal particles can be further manipulated by fine-tuning the functional groups, such as oxygen groups, and by B/N-doping of the CNFs. The possibilities of using carbon nanofibers with different graphite-sheet orientations as a platform for rational catalyst design are discussed. [ABSTRACT FROM AUTHOR]

Abstract: Platinum nanoparticles (Pt-NPs) were deposited onto N-(trimethoxy-silylpropyl) ethylenediamine triacetic acid (EDTA-silane) modified reduced graphene oxide (EDTA-RGO). The EDTA-RGO/Pt-NPs were coated onto a glass carbon electrode and characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectra, and electrochemical tests. The chelating groups create a micro-environment that is suitable for the catalytic behavior of Pt-NPs. Compared with traditional carbon-based Pt catalysts, EDTA-RGO/Pt-NPs exhibit great tolerance towards poisoning by CO. Graphene-supported Pt nanoparticles can be used for the fabrication of fuel cell electrodes and other catalytic devices. [Copyright &y& Elsevier]

Abstract: A novel electrochemical sensor for chlorophenols was fabricated by using the Pd-graphene nanocomposite and ions liquid. The Pd-graphene nanocomposite was prepared via a sonoelectrochemical route, and the possible formation mechanism was proposed. Transmission electron microscopy, scanning electron microscopy, X-ray diffraction and Raman spectrum were used for the characterization of structure and morphology of the nanocomposite. The experimental results showed that Pd nanospheres comprised of small Pd nanoparticles were uniformly attached on graphene sheets. The electrocatalytic properties were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV), which indicated that the Pd-graphene nanocomposite had high activity for chlorophenol oxidation. Herein, 2-chlorophenol was selected as the model molecules. The results showed that graphene played an important role in the fabrication of the chlorophenols sensor. The nanocomposite with large electrochemical active surface led to the excellent electrocatalytic activity, and ionic liquid further enhanced the catalytic activity of Pd-graphene for chlorophenols. [Copyright &y& Elsevier]

Abstract: The sorption of Cu as affected by pH, ionic strength, competitor heavy metal, and inorganic and organic ligands on a Fe-deformed montmorillonite complex was observed in the current study. The results showed that the sorption of Cu was pH dependent and insensitive to a change of ionic strength, indicating that the formation of an inner-sphere complex was the primary sorption mechanism, and it was probably due to the high surface coverage of Fe (oxyhydr)oxides as nanoparticles on deformed montmorillonite. Copper was less effective than Pb in competitive sorption. Phosphate, sulfate and oxalate showed different characteristics in affecting Cu sorption. Phosphate inhibited Cu sorption at a relatively low ligand concentration while a facilitating effect was observed when the concentration of phosphate was relatively high. The sorption of Cu was generally promoted by sulfate but the extent was less than that by phosphate. Oxalate promoted Cu sorption at a relatively low pH (pH 3.5) and a relatively low oxalate concentration, while a significant diminution of Cu sorption was found at higher pHs (pH 4.5 and 5.5) or a relatively high ligand concentration. The results obtained in the current study are of significant importance for evaluating the mobility of Cu in polluted environment. [Copyright &y& Elsevier]

Abstract: The gold nanoparticles/colloidal carbon sphere hybrid material was used for the immobilization of protein, and was developed in biosensing. The hybrid material was fabricated by the assembly of gold nanoparticles onto the surface of colloidal carbon spheres, which constructed a 3D antibody immobilization matrix on the glass carbon electrode and made the immobilized biomolecules hold high stability and bioactivity. After the sandwich-type immunoreaction, the formed HRP-labeled immunoconjugate showed good enzymatic activity for the oxidation of o-phenylenediamine by H2O2. The approach provided a linear response range between 5 and 250ng/mL with a detection limit of 1.8ng/mL. The immunosensor showed good precision, acceptable stability and reproducibility and could be used for the detection of human IgG in real samples, which provided a potential alternative tool for the detection of protein in clinical laboratory. [ABSTRACT FROM AUTHOR]

Abstract: Porous spheres of CuSCN nanoparticles with an average diameter of 0.4–0.6 μm have been prepared by a simple reaction between CuO suspension, NH2OH and KSCN in the presence of gelatin at 10 °C. Gelatin played a decisive role as an inhibitor of the direct attack of NH2OH, KSCN to CuO surfaces and coagulation of the growing CuSCN in producing porous spheres. The products were characterized by X-ray powder diffraction, transmission electron microscopy, and X-ray photoelectron spectra techniques. [Copyright &y& Elsevier]

Cubes of CuBr with an average dimensions of 0.3–0.8 μm have been prepared by a simple reaction between CuO suspension, NH2OH and KBr in the presence of deionized gelatin at 40°C. Gelatin played a decisive role as an inhibitor of the direct attack of NH2OH, KBr to CuO surfaces and coagulation of the growing CuBr in producing the cubes. The products were characterized by X-ray powder diffraction, transmission electron microscopy, X-ray photoelectron spectra techniques and UV-visible absorption spectroscopy. The sizes of the subunits of the polycrystalline CuBr particles were estimated by Debye–Scherrer formula according to XRD spectrum. [Copyright &y& Elsevier]

A novel nano-sized copper oxide modified carbon paste electrode has been fabricated to determine the amikacin by cyclic voltammetry and amperometry. The oxidation current of the amikacin on nano-sized copper oxide modified carbon paste electrode was about 40 times higher than that on bulk CuO modified carbon paste electrode. The curve of i vs. concentration was linear in the range of 2–200 µM of the amikacin concentration with a correlation coefficient of 0.998. The detection limit was ca. 1 µM of amikacin with the signal to noise ratio of 3. [ABSTRACT FROM AUTHOR]

Au and Ag Noble metals nanowire arrays have been successfully prepared by a photochemical method in porous anodic aluminum oxide template from an aqueous solution of HAuCl4 and AgNO3 in the presence of polymer capping materials PVA at room temperature. The products were characterized by XRD, TEM and SEM. These nanowires have uniform diameters of about 20 nm, which correspond to the pore sizes of the templates used, and lengths are up to tens of micrometers. This approach can be used to fabricate crystalline nanowire arrays of a wide range of other metals and semiconductor materials. [Copyright &y& Elsevier]

A convenient sonochemical process for the preparation of HgSe nanoparticles by using different reductants has been discovered. The HgSe nanoparticles, which were prepared in polyethylene glycol 400 (PEG 400), dextrose and hydroxylamine reductive systems, were analyzed by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). It was found that all the products were cubic phase HgSe by XRD measurements. The TEM observations showed that the HgSe nanoparticles were monodispersed and electron diffraction images of selected areas show that the products were polycrystalline. The sizes of most of all the HgSe nanoparticles were mainly among 30–40 nm, which were in coincidence with the very sizes that were estimated by Debye–Scherrer equation from the XRD patterns. XPS result showed that the ratio of Hg to Se was 57:43, indicating that the final products were rich in mercury. [Copyright &y& Elsevier]

Hollow spheres of Cu2O with an average diameter of 0.3–0.6 μm have been prepared by a simple reaction between CuO suspension and NH2OH in the presence of deionized gelatin at room temperature. Gelatin played a decisive role as an inhibitor of the direct attack of NH2OH to CuO surfaces and coagulation of the growing Cu2O in producing the hollow spheres. The products were characterized by X-ray powder diffraction, transmission electron microscopy, X-ray photoelectron spectra techniques and UV-visible absorption spectroscopy. The band gap is estimated to be 2.60 eV according to the results of optical measurements of the hollow spheres. [Copyright &y& Elsevier]

An electrochemical immunosensor has been constructed by the self-assemble technique and studied by the AC impedance and potential method respectively. The change of the surface impedance shows that the antibody can be assembled on the electrode surface and recognize the antigen. The gold nanoparticles are not only used to immobilize the CRP antibody, but also can amplify the potential response. The immunosensor responds to antigen in the linear range from 5 to 25 µg/mL and can meet the needs of clinical assay. [ABSTRACT FROM AUTHOR]

Rectangular lead selenide and cadmium selenide nanoparticles have been successfully prepared by a photochemical method from an aqueous solution of lead acetate, cadmium chlorate, and sodium selenosulfate in the presence of complexating agents of nitrilotriacetic acid at room temperature. It was found that the effects of the photonic intensity, the pH of the solution, and the species of complexating agents played important roles on the morphology control of the PbSe and CdSe nanoparticles. The products were characterized by X-ray diffraction, electron microscopy, X-ray photoelectron spectra, and photoluminescence spectrum. The mechanism for the formation of the PbSe and CdSe was discussed. [Copyright &y& Elsevier]

Nanocrystalline SnO2 powders of about 3 nm in size have been prepared by a microwave irradiation heating technique from an aqueous solution in the presence of SnCl4 and urea. The nanocrystalline SnO2 particles were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), differential scanning calorimetric (DSC), thermogravimetric analysis (TG), and reflection spectrum. A bandgap is estimated to be 4.5 eV from the optical measurement of the nanoparticles. [Copyright &y& Elsevier]

In this study, we proposed 'switching ultrasonic amplitude' as a new strategy of applying ultrasonic energy to prepare a hybrid of buckminsterfullerene (C 60) and gallium oxide (Ga 2 O 3), C 60 /Ga 2 O 3. In the proposed method, we switched the ultrasonic amplitude from 25% to 50% (by 5% amplitude per 10 min, within 1 h of ultrasonic irradiation) for the sonochemical treatment of a heterogeneous aqueous mixture of C 60 and Ga 2 O 3 by a probe-type ultrasonic horn operating at 20 kHz. We found that compared to the conventional techniques associated with high amplitude oriented ultrasonic preparation of functional materials, switching ultrasonic amplitude can better perform in preparing C 60 /Ga 2 O 3 with respect to avoiding titanium (Ti) as an impurity generating from the tip erosion of a probe-type ultrasonic horn during high amplitude ultrasonic irradiation in an aqueous medium. Based on SEM/EDX analysis, the quantity of Ti (wt.%) in C 60 /Ga 2 O 3 prepared by the proposed technique of switching ultrasonic amplitude was found to be 1.7% less than that prepared at 50% amplitude of ultrasonic irradiation. The particles of C 60 /Ga 2 O 3 prepared by different modes of amplitude formed large (2–12 μm) aggregates in their solid phase.Whereas, in the aqueous medium, they were found to disperse in their nano sizes. The minimum particle size of the as-synthesized C 60 /Ga 2 O 3 in an aqueous medium prepared by the proposed method of switching ultrasonic amplitude reached to approximately 467 nm. Comparatively, the minimum particle sizes were approximately 658 nm and 144 nm, using 25% and 50% amplitude, respectively. Additionally, Ga 2 O 3 went under hydration during ultrasonic irradiation. Moreover, due to the electron cloud interference from C 60 in the hybrid structure of C 60 /Ga 2 O 3 , the vibrational modes of Ga 2 O 3 were Raman inactive in C 60 /Ga 2 O 3. [ABSTRACT FROM AUTHOR]

• Silver nanorods/nanowires were prepared within the range of sub-20 nm diameter. • The diameter can be controlled, as small as 12 nm, using 5-nm spherical Au seeds. • One-dimensional trimetallic (Au@Pd-Ag) hollow products were prepared via GRR. We report a facile synthesis of silver nanorods/nanowires with the diameter in the range of sub-20 nm via seeded growth. The key to the success of this work relies on the use of tiny Au seeds and manipulation over reaction kinetics. In particular, their diameter could be controlled to as small as 12 nm using 5-nm spherical Au seeds. They can be further converted to trimetallic (Au@Ag-Pd) hollow derivatives with tunable hollow degree and elemental compositions by galvanic replacement reaction. [ABSTRACT FROM AUTHOR]

Endometrial cancer (EC) is a common gynecological malignancy worldwide whose therapy mainly depends on chemotherapy. In past years, an increasing number of studies indicate that hollow MnO2 could serve as a nanoplatform in the drug delivery system. The Brucea javanica oil emulsion (BJOE) has been illustrated to play a vital role in cancers. However, knowledge about the combined effect of H-MnO2-PEG/BJOE in endometrial cancer remains ambiguous up to now. In the present work, we prepared a drug-delivery vector H-MnO2-PEG by chemical synthesis and found that H-MnO2-PEG significantly inhibited cell proliferation in endometrial cancer cells. Moreover, the combination of H-MnO2-PEG/BJOE could repress cell proliferation more efficiently and promote cell apoptosis. Mechanistically, we found that BJOE exerted its role as a promoter of endometrial apoptosis by regulating relative protein expressions. In general, the present study demonstrates that H-MnO2-PEG functions as a critical vector in the tumor microenvironment of endometrial cancer and the significant effect of H-MnO2-PEG/BJOE on cancer cells, suggesting a new paradigm for the treatment of endometrial cancer. [ABSTRACT FROM AUTHOR]

Protein coronas are present extensively at the bio‐nano interface due to the natural adsorption of proteins onto nanomaterials in biological fluids. Aside from the robust property of nanoparticles, the dynamics of the protein corona shell largely define their chemical identity by altering interface properties. However, the soft coronas are normally complex and rapidly changing. To real‐time monitor the entire formation, we report here a self‐regulated electrochemiluminescence (ECL) microscopy based on the interaction of the Ru(bpy)33+ with the nanoparticle surface. Thus, the heterogeneity of the protein corona is in situ observed in single nanoparticle "cores" before and after loading drugs in nanomedicine carriers. The label‐free, optical stable and dynamic ECL microscopy minimize misinterpretations caused by the variation of nanoparticle size and polydispersity. Accordingly, the synergetic actions of proteins and nanoparticles properties are uncovered by chemically engineered protein corona. After comparing the protein corona formation kinetics in different complex systems and different nanomedicine carriers, the universality and accuracy of this technique were well demonstrated via the protein corona formation kinetics curves regulated by competitive adsorption of Ru(bpy)33+ and multiple proteins on surface of various carriers. The work is of great significance for studying bio‐nano interface in drug delivery and targeted cancer treatment. [ABSTRACT FROM AUTHOR]

Protein coronas are present extensively at the bio‐nano interface due to the natural adsorption of proteins onto nanomaterials in biological fluids. Aside from the robust property of nanoparticles, the dynamics of the protein corona shell largely define their chemical identity by altering interface properties. However, the soft coronas are normally complex and rapidly changing. To real‐time monitor the entire formation, we report here a self‐regulated electrochemiluminescence (ECL) microscopy based on the interaction of the Ru(bpy)33+ with the nanoparticle surface. Thus, the heterogeneity of the protein corona is in situ observed in single nanoparticle "cores" before and after loading drugs in nanomedicine carriers. The label‐free, optical stable and dynamic ECL microscopy minimize misinterpretations caused by the variation of nanoparticle size and polydispersity. Accordingly, the synergetic actions of proteins and nanoparticles properties are uncovered by chemically engineered protein corona. After comparing the protein corona formation kinetics in different complex systems and different nanomedicine carriers, the universality and accuracy of this technique were well demonstrated via the protein corona formation kinetics curves regulated by competitive adsorption of Ru(bpy)33+ and multiple proteins on surface of various carriers. The work is of great significance for studying bio‐nano interface in drug delivery and targeted cancer treatment. [ABSTRACT FROM AUTHOR]

The front cover of the journal is presented.

Abstract: Herein, we reported the quenching effect of Ni2+ on bovine serum albumin protected fluorescent gold nanoparticles (BSA-GNPs). The quenching mechanism was discussed and a static quenching mechanism was proposed. The number of binding sites (n), apparent stability constants (K) and corresponding thermodynamic parameters of BSA-GNPs-Ni2+ complex were measured at different temperatures. Under optimum conditions, the fluorescence intensity of BSA-GNPs is linearly proportional to nickel concentration from 6.0×10−8 mol/L to 8.0×10−6 mol/L with a detection limit of 1.0×10−8 mol/L. The result indicated that BSA-GNP was a potential Ni2+ probe. [Copyright &y& Elsevier]

Abstract: TiO2 nanoparticles were homogeneously coated on multiwalled carbon nanotubes (MWCNTs) by hydrothermal deposition, and this nanocomposite might be a promising material for myoglobin (Mb) immobilization in view of its high biocompatibility and large surface. The glassy carbon (GC) electrode modified with Mb–TiO2/MWCNTs films exhibited a pair of well-defined, stable and nearly reversible cycle voltammetric peaks. The formal potential of Mb in TiO2/MWCNTs film was linearly varied in the range of pH 3–10 with a slope of 48.65 mV/pH, indicating that the electron transfer was accompanied by single proton transportation. The electron transfer between Mb and electrode surface, k s of 3.08 s−1, was greatly facilitated in the TiO2/MWCNTs film. The electrocatalytic reductions of hydrogen peroxide were also studied, and the apparent Michaelis–Menten constant is calculated to be 83.10 μM, which shows a large catalytic activity of Mb in the TiO2/MWCNTs film to H2O2. The modified GC electrode shows good analytical performance for amperometric determination of hydrogen peroxide. The resultant Mb–TiO2/MWCNTs modified glassy carbon electrode exhibited fast amperometric response to hydrogen peroxide reduction, long term life and excellent stability. Finally the activity of the sensor for nitric oxide reduction was also investigated. [Copyright &y& Elsevier]

Abstract: The photoluminescence from water-soluble gold nanoparticles, each composed of a 5.1nm gold core and a bovine serum albumin (BSA)-protected layer, has been observed. The maximal excitation and the maximal emission wavelength are at 320 and 404nm, respectively. The photoluminescence quantum yield is estimated as 0.053±0.0070, at room temperature. The mechanism of the luminescence is hypothesized to be associated with interband transitions between the filled 5d10 band and 6(sp)1 conduction band. The photoluminescence is sensitive to pH, organic solvents and metal ions. These observations suggest that this nanoparticles are a viable alternative to organic fluorophores or semiconductor nanoparticles for biological labeling and imaging. [Copyright &y& Elsevier]

Abstract: Composition of nanostructured metal particles on oxide tubes (TiO2 and ZrO2) were fabricated and characterized. The composite materials were examined by transmission electron microscopy, scanning electron microscopy, FT-IR absorption, and UV–visible absorption spectra. The results of characterization showed that the composites indeed contained both oxide tubes and gold nanoparticles and that the gold nanoparticles were intimately associated with the nanotubes. [Copyright &y& Elsevier]

Abstract: Antimony dendrites have been successfully synthesized by a microwave-assisted method under ambient air from the solution containing antimony sodium tartrate. In the reaction, zinc powders were selected as a reductant for the fabrication. The as-prepared products were characterised by X-ray powder diffraction, transmission electron microscopy, and selected area electron diffraction. The dendrites were found to be composed of well-crystallized nanoflakes with size of 20–40 nm. [Copyright &y& Elsevier]

CuO nanoparticles with an average size of ca. 4 nm have been successfully prepared by microwave irradiation, using copper (II) acetate and sodium hydroxide as the starting materials and ethanol as the solvent. The CuO nanoparticles are characterized by using techniques such as X-ray powder diffraction, transmission electron microscopy, selected area electron diffraction, X-ray photoelectron spectroscopy and UV–Visible absorption spectroscopy. The as-prepared CuO nanoparticles have regular shape, narrow size distribution and high purity. The band gap is estimated to be 2.43 eV according to the results of the optical measurements of the CuO nanoparticles. [Copyright &y& Elsevier]

• This study explores the free vibration and bending of FG-GPLRC spherical shells based on the three-dimensional elasticity theory. • The analytical solutions are obtained. • Further illustrative parametric investigations are performed with respect to the distribution pattern, the weight fraction, and the geometric parameters of GPLs. • For free vibration, the FG-A, FG-O and FG-X increase the natural frequencies of breathing, torsional and fundamental modes more effectively, respectively; While for bending, FG-X possesses the smallest displacement, and FG-V holds the lowest stress. This paper presents analytical investigations on the free vibration and static bending of functionally graded graphene-reinforced nanocomposite (FG-GPLRC) spherical shells. The GPL nanofillers are dispersed into polymer matrix uniformly and un-uniformly in the thickness direction with a piece-wise type, and UD, FG-O, FG-X, FG-V and FG-A types of GPL distribution patterns are taken into account. The effective material properties of graphene-reinforced nanocomposites are estimated by using the modified Halpin-Tsai multi-scaled model and the rule of mixtures. Governing differential equations for free vibration and bending of the FG-GPLRC spherical shells are derived based on the three-dimensional elasticity theory with the aid of the state space method, and the layer-wise model is employed to obtain the analytical solutions. The validity of the present method is first examined, followed by the illustrative parametric studies to further scrutinize the free vibration and static bending behaviors of the FG-GPLRC spherical shells with the various reinforcement schemes, including the distribution pattern, the weight fraction, and geometric parameter of GPLs in details. [ABSTRACT FROM AUTHOR]

We report a new strategy to prepare a composite catalyst for highly efficient electrochemical CO2 reduction reaction (CO2RR). The composite catalyst is made by anchoring Au nanoparticles on Cu nanowires via 4,4′‐bipyridine (bipy). The Au‐bipy‐Cu composite catalyzes the CO2RR in 0.1 m KHCO3 with a total Faradaic efficiency (FE) reaching 90.6 % at −0.9 V to provide C‐products, among which CH3CHO (25 % FE) dominates the liquid product (HCOO−, CH3CHO, and CH3COO−) distribution (75 %). The enhanced CO2RR catalysis demonstrated by Au‐bipy‐Cu originates from its synergistic Au (CO2 to CO) and Cu (CO to C‐products) catalysis which is further promoted by bipy. The Au‐bipy‐Cu composite represents a new catalyst system for effective CO2RR conversion to C‐products. [ABSTRACT FROM AUTHOR]

We report a new strategy to prepare a composite catalyst for highly efficient electrochemical CO2 reduction reaction (CO2RR). The composite catalyst is made by anchoring Au nanoparticles on Cu nanowires via 4,4′‐bipyridine (bipy). The Au‐bipy‐Cu composite catalyzes the CO2RR in 0.1 m KHCO3 with a total Faradaic efficiency (FE) reaching 90.6 % at −0.9 V to provide C‐products, among which CH3CHO (25 % FE) dominates the liquid product (HCOO−, CH3CHO, and CH3COO−) distribution (75 %). The enhanced CO2RR catalysis demonstrated by Au‐bipy‐Cu originates from its synergistic Au (CO2 to CO) and Cu (CO to C‐products) catalysis which is further promoted by bipy. The Au‐bipy‐Cu composite represents a new catalyst system for effective CO2RR conversion to C‐products. [ABSTRACT FROM AUTHOR]

Abstract The behavior of clay minerals in different size fractions of soil colloids are very particular, mostly in the nanoparticle (25–100 nm) fractions, where clay minerals are very reactive and have a significant role in the transport of nutrients. In this work, the characterizations of clay minerals in the particle fractions (<2000, 450–2000, 100–450, and 25–100 nm) of an Oxisol and an Alfisol were studied by conventional and synchrotron X-ray diffraction (XRD), fourier-transform infrared spectroscopy (FTIR), inductively coupled plasma-optical emission spectroscopy (ICP-OES), and thermogravimetric analysis (TG) to better understand the transformations of clay minerals and their crystalline structure within the size particle fractions. Kaolinite dominated in all the particle size fractions and the moderate amount of HIV and illite present in the larger size particles (<2000, 450–2000 and 100–450 nm) reduced gradually in nanoparticles of the Oxisol. Kaolinite dominated in the bulk samples (<2000 nm), vermiculite prevailed in the 450–2000 nm fraction; illite, kaolinite and vermiculite were equally common in the 100–450 nm fractions, and illite dominated in the nanoparticles of the Alfisol. The reduction of kaolinite and the transformation of illite into vermiculite in the Alfisol occurred along the particle size fractions. The increase of the FWHM values, the deformation of the hydroxyl group of kaolinite and illite as well as the highest total of weight loss in their crystals occurred in the nanoparticles of the Alfisol rather than the Oxisol. It revealed that the reduction in crystal ordering in the crystals of clay minerals was greater in the nanoparticle fraction of the Alfisol compared to the Oxisol. The influence of climate, vegetation, parent material has been evidenced in the transformation of clay minerals in this study. Highlights • Illite dominated in the nanoparticles of Alfisol while kaolinite was in the Oxisol. • Illite and HIV have contributed to form kaolinite from nanoparticles in the Oxisol. • In the Alfisol, kaolinite strongly reduced with decreasing particle size fractions. • The disorder was significant in the clay mineral's crystalline structure of Alfisol. • Climate, vegetation, parent material have contributed to transform clay minerals [ABSTRACT FROM AUTHOR]

The accurate therapeutic evaluation for chronic myeloid leukemia (CML) drug is of great importance to minimize side effects and enhance efficacy. Herein, a facile and precise surface-enhanced scattering (SERS) approach based on coupled plasmonic field has been introduced to evaluate the therapeutic outcomes of antileukemia drug through ultrasensitive assay of caspase-3 activity in apoptotic cells. Caspase-3 as an apoptosis indicator could specifically cleave the N-terminus of biotinylated DEVD-peptide (biotin-Gly-Asp-Gly-Asp-Glu-Val-Asp-Gly-Cys) immobilized on the Au nanoparticle-decorated TiO 2 nanotube arrays (TiO 2 /Au NTAs) substrate. After the enzyme cleavage with caspase-3, Raman-labelled Au nanostar (AuNS) probes captured the residual DEVD-peptides via the recognition between streptavidin and biotin, thus resulting in an enhanced Raman response on the SERS platform. The variation of Raman intensity revealed caspase-3 activity that reflected the chemotherapeutic effect. On this platform, AuNS nanoprobes offered a large number of binding sites and intrinsic “hot spots” for Raman reporters, while TiO 2 /Au NTAs rendered a homogenously coupled electromagnetic field between the adjacent repeated units over the large area. In particular, a spatially expanding plasmonic field formed by coupling AuNSs with TiO 2 /Au NTAs would further heighten Raman enhancement. Taking these advantages, the strong and uniform Raman signals were achieved. Furthermore, the practicability investigation witnessed that the proposed SERS strategy was available to evaluate the therapeutic effect of dasatinib on CML K562 cells. The developed method possesses fascinating advantages of cost-effectiveness, excellent reproducibility and high sensitivity, which endows it with promising potential in apoptosis monitoring and anticancer drug development. [ABSTRACT FROM AUTHOR]

Three dimensional carbon materials with hirerarchically porous structure could exhibit superior energy storage performance than two dimensional stacked carbon nanosheet materials. In this work, we prepared a novel ZIF-8-derived nitrogen doped carbon nanoparticles/graphitic carbon nitride composite electrode material with high electrochemical energy storage performances, including high specific capacitances (495 F g −1 at 0.1 A g −1 and 188 F g −1 at 20 A g −1 ) and a stable cycling durability with no capacitance declination after 5000 charge-discharge cycles in three-electrode system. When assembled as electrode materials in symmetrical two-electrode system, the as-prepared composite electrode material could exhibit high specific capacitances of 349.7 F g −1 at 0.5 A g −1 and 261.2 F g −1 at 5 A g −1 . Accordingly, a high energy density of 11.89 Wh/kg can be achieved at the power density of 247.40 W kg −1 . The improvement stems from its hierarchically porous structure with dominant pore sizes at 3 nm and among 4–40 nm, as well as high exposed pyridinic nitrogen (8.58 at%) and pyrrolic nitrogen (3.59 at%) active sites caused by the insertion of ZIF-8-derived nitrogen doped carbon nanoparticles between g-CN layers. This study has provided a new idea on the design of graphitic carbon nitride nanostructures with improved doping level and hiearchically porous structure. [ABSTRACT FROM AUTHOR]

The enhancement of microbial activity and electrocatalysis through the design of new anode materials is essential to develop microbial fuel cells (MFCs) with longer lifetimes and higher output. In this research, a novel anode material, graphene/Fe3O4 (G/Fe3O4) composite, has been designed for Shewanella-inoculated MFCs. Because the Shewanella species could bind to Fe3O4 with high affinity and their growth could be supported by Fe3O4, the bacterial cells attached quickly onto the anode surface and their long-term activity improved. As a result, MFCs with reduced startup time and improved stability were obtained. Additionally, the introduction of graphene not only provided a large surface area for bacterial attachment, but also offered high electrical conductivity to facilitate extracellular electron transfer (EET). The results showed that the current and power densities of a G/Fe3O4 anode were much higher than those of each individual component as an anode. [ABSTRACT FROM AUTHOR]

CO oxidation has been performed on Co 3 O 4 nanocubes and Co(OH) 2 nanosheets as model catalysts. The reaction rate of CO on Co 3 O 4 /Co(OH) 2 nanocomposites obtained by one-pot synthesis is about ~ two orders of magnitude higher than that on Co 3 O 4 nanomaterials. The catalytic behaviors of different nanomaterials revealed that the assembly with nano building blocks cause the catalytic sites much more active for CO oxidation. The kinetic data showed that the activation energy for CO oxidation over Co 3 O 4 /Co(OH) 2 nanocomposites was lower than that of other nanomaterials. Since Co(OH) 2 nanosheets can prevent Co 3 O 4 nanocubes aggregating, nanocomposites kept good catalytic stability. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) is a noninvasive and site-specific therapeutic technique for the clinical treatment of various of superficial diseases. In order to tuning the operation wavelength and improve the tissue penetration of PDT, rare-earth doped upconversion nanoparticles (UCNPs) with strong anti-stokes emission are introduced in PDT recently. However, the conventional Yb3+-sensitized UCNPs are excited at 980 nm which is overlapped with the absorption of water, thus resulting in strong overheating effect. Herein, a convenient but effective design to obtain highly emissive 795 nm excited Nd3+-sensitized UCNPs (NaYF4:Yb,Er@NaYF4:Yb0.1Nd0.4@NaYF4) is reported, which provides about six times enhanced upconversion luminescence, comparing with traditional UCNPs (NaYF4:Yb,Er@NaYF4). A colloidal stable and non-leaking PDT nanoplatform is fabricated later through a highly PEGylated mesoporous silica layer with covalently linked photosensitizer (Rose Bengal derivative). With as-prepared Nd3+-sensitized UCNPs, the nanoplatform can produce singlet oxygen more effective than traditional UCNPs. Significant higher penetration depth and lower overheating are demonstrated as well. All these features make as-prepared nanocomposites excellent platform for PDT treatment. In addition, the nanoplatform with uniform size, high surface area, and excellent colloidal stability can be extended for other biomedical applications, such as imaging probes, biosensors, and drug delivery vehicles. [ABSTRACT FROM AUTHOR]

The composition, structure and transformation characteristics of clay minerals in various size particles (< 2000, 450–2000, 100–450 and 25–100 nm) of two Alfisols (Haplustalf and Hapludalf) in China were investigated by elemental analysis, X-ray diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FT-IR) and 27 Al and 29 Si Magic-angle Spinning Nuclear Magnetic Resonance (MAS NMR). The clay minerals in < 2000, 450–2000 and 100–450 nm size particles of the two soils were illite, vermiculite, smectite, kaolinite and kaolinite interstratified minerals. In Haplustalf, vermiculite was dominant clay mineral in 450–2000 nm particles and illite was dominant clay mineral in 100–450 nm particles. In Hapludalf, kaolinite (and kaolinite interstratified minerals) predominated in all size particles. With decreasing particle sizes, the two clays showed a decrease in K 2 O, Na 2 O, MgO and SiO 2 contents and an increase in Al 2 O 3 content, with the minimum molar ratio of SiO 2 to Al 2 O 3 observed in nanoparticles (25–100 nm). Meanwhile, the smectite and vermiculite contents decreased or disappeared, leaving illite and kaolinite (and kaolinite interstratified minerals) as the main clay minerals in the two soil nanoparticles. Additionally, with decreasing particle sizes, the clay mineral structures were transformed from well crystalline to poor crystalline, with illite being the poor crystalline in nanoparticles of the soils. The hydroxyl groups between the tetrahedral and octahedral structures of the 2:1 clay minerals and the surface of kaolinite gradually broke down, and IV Al of the tetrahedral structure gradually reduced. In nanoparticles, Al mainly appeared in the octahedral structure as VI Al, and Si in the structure of Q 3 (Si linked to three other Si atoms via oxygen). The composition and structure of clay minerals in different size particles showed that the clay minerals weathered from larger particles (> 100 nm) were an important mineral source of nanoparticles, and the 1:1 clay minerals were mainly inherited from the minerals in larger particles and transformed from 2:1 clay minerals into nanoparticles. [ABSTRACT FROM AUTHOR]

Heterogeneous ZnInS/g-CN hybrid composites, as highly efficient visible-light-driven photocatalysts, were designed and fabricated by a simple one-step hydrothermal route for the first time, wherein the cubic ZnInS nanoparticles were in situ immobilized on the surface of porous g-CN nanosheets (NSs). The resultant composites exhibit efficient photocatalytic activities, excellent photo-stability, and versatile photocatalytic abilities towards organic dye degradation, Cr(VI) reduction, and water splitting for H evolution. The significant enhancement of photocatalytic activity is attributed to the effective separation of photo-generated charge carrier pairs based on the construction of close heterogeneous interface and well-matched band structure, which can obviously lengthen the life span of holes and electrons pairs. Besides, the effective charge transfer from cubic ZnInS to ultrathin g-CN NSs was confirmed by photoluminescence spectra, transient photocurrent-time ( I- t) curves and electrochemical impedance spectroscopy Nyquist plots. This research provides a new sight in designing the highly efficient visible light responsive photocatalysts for environmental remediation and energy production. [ABSTRACT FROM AUTHOR]

We report on a sensitive electrochemical immunoassay for the prostate specific antigen (PSA). An immunoelectrode was fabricated by coating a glassy carbon electrode with multiwalled carbon nanotubes, poly(dimethyldiallylammonium chloride), CeO and PSA antibody (in this order) using the layer-by-layer method. The immunosensor is then placed in a sample solution containing PSA and o-phenylenediamine (OPD). It is found that the CeO nanoparticles facilitate the electrochemical oxidation of OPD, and this produces a signal for electrochemical detection of PSA that depends on the concentration of PSA. There is a linear relationship between the decrease in current and the concentration of PSA in the 0.01 to 1,000 pg mL concentration range, and the detection limit is 4 fg mL. The assay was successfully applied to the detection of PSA in serum samples. This new differential pulse voltammetric immunoassay is sensitive and acceptably precise, and the fabrication of the electrode is well reproducible. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A novel fluorescent immunosensor was developed based on the use of CuS nanoparticles (CuS NPs) as labels for the highly sensitive detection of human prostate cancer biomarker prostate specific antigen (PSA). In the presence of CuS NPs, the non-fluorescent substrate o-phenylenediamine could be oxidized into the stable fluorescent product 2,3-diamiophenazine at physiological pH. Throughout the reaction, no other oxidizing agents (e.g. hydrogen peroxide) were needed. The relatively mild oxidation conditions made the immunoassay robust, reliable and facile. The proposed immunoassay exhibited high sensitivity and specificity for the detection of PSA. A linear relationship between the fluorescent signals and the concentration of PSA was obtained in the range of 0.5 pg mL−1 to 50 ng mL−1, with a detection limit of 0.1 pg mL−1 (S/N = 3). The proposed fluorescent immunoassay can be used as a promising platform for the detection of a variety of other biomarkers. [ABSTRACT FROM AUTHOR]

A robust, nanobiotechnology-based electrochemical cytosensing platform for the detection of acute leukemia cells was developed with high sensitivity, selectivity, acceptable rapidity and excellent extensibility. It utilized the competitive binding of cell-specific aptamers to acute leukemia cells and subsequent voltammetric quantification of the metal signature. Greatly enhanced sensitivity was achieved with dual signal amplification by using Fe3O4 magnetic nanoparticles (MNPs) as carriers to load a large amount of gold nanoparticles (AuNPs) and AuNP-catalyzed silver deposition. The proposed competitive cytosensor showed high sensitivity with a detection limit down to 10 cells. This simple and low-cost electrochemical cytosensing approach offers great promise to extend its application to early detection of human leukemia and possibly to other cancer cells. [ABSTRACT FROM AUTHOR]

Abstract: Covalent organic frameworks (COFs) are a new generation of porous materials constructed from light elements linked by strong covalent bonds. Herein we present rapid preparation of highly fluorescent nanoparticles of a new type of COF, i.e. melamine-based porous polymeric network SNW-1, by a microwave-assisted synthesis route. Although the synthesis of SNW-1 has to be carried out at 180°C for 3d under conventional reflux conditions, SNW-1 nanoparticles could be obtained in 6h by using such a microwave-assisted method. The results obtained have clearly demonstrated that microwave-assisted synthesis is a simple yet highly efficient approach to nanoscale COFs or other porous polymeric materials. Remarkably, the as-synthesized SNW-1 nanoparticles exhibit extremely high sensitivity and selectivity, as well as fast response to nitroaromatic explosives such as 2,4,6-trinitrotoluene (TNT), 2,4,6-trinitrophenylmethylnitramine (Tetryl) and picric acid (PA) without interference by common organic solvents, which is due to the nanoscaled size and unique hierarchical porosity of such fluorescence-based sensing material. [Copyright &y& Elsevier]

Abstract: PbS and Bi2S3 nanocrystals with well-controlled sizes and shapes were easily produced from molecular precursors (xanthate) in ethylene diamine (en) solution at room temperature. When lead or bismuth ethylxanthate were added into en solution, the precipitates were instantly formed, and subsequently, PbS cubes and flower-like Bi2S3 hierarchical structures were obtained if the mixtures were left still for 5days under ambient conditions. This work not only provides a facile route to synthesize chalcogenides with well-defined nano- and microstructures in a solution-phase system, but also gives insight into understanding on decomposition behavior of molecular precursors in various solvents. [Copyright &y& Elsevier]

Abstract: A sensitive colorimetric detection for biomolecules based on aptamer was described. Poly(dimethylsiloxane) (PDMS)–gold nanoparticles (AuNPs) composite film was used as a platform for immobilizing anti-target aptamer. PDMS–AuNPs composite film only covered with aptamer showed high inhibiting ability towards silver reduction, after target molecules were conjugated on the modified surface, the catalytic efficiency of AuNPs for silver reduction was increased. In this system, the darkness density of silver enhancement was applied for target quantitative measurement. Lysozyme and adenosine 5′-triphosphate (ATP) were tested as the models, quantitative measurements with imaging software or semiquantitative measurements with naked eyes were carried out in the range of 1×10−2–1μg/mL and 1×10−4–1×103 μg/mL, the volume of reagent using in each assay is 15μL or less. We speculated that aptamer-target conjugates’ inhibition ability for AuNPs’ catalytic efficiency toward silver reduction might come from charge and spatial effects. This study can offer a completely novel and relatively general approach for colorimetrical aptamer sensors with good analytical properties and potential applications. The sensor could be coupled with digital transmission of images for remote monitoring system in diagnosis, food control, and environmental analysis. [Copyright &y& Elsevier]

Abstract: In this paper, stabilizer-free gold nanoparticles (Au NPs) were synthesized by a facile pulse sonoelectrochemical method in the absence of stabilizer. The size and shape of the Au NPs can be controlled by adjusting current density, reaction time and the pH value of the precursor solution. The morphology and structure of the Au NPs were characterized by transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), UV–visable spectra (UV–vis), energy-dispersive X-ray (EDX) and X-ray diffraction (XRD). The pH value has a great effect on the size and dispersion of the obtained Au NPs. The Au NPs could further used as substrate for fabrication of HRP biosensor which exhibited excellent biocatalytical activity with high sensitivity and rapid response. This method provides a facile route for the synthesis of stabilizer-free Au NPs. Since the preparation process do not need the addition of any surfactants/capping agent, the resulting Au NPs are suitable for the applications in fields of biology and catalysis. [Copyright &y& Elsevier]

Abstract: An electroosmotic flow (EOF)-switchable poly(dimethylsiloxane) (PDMS) microfluidic channel modified with cysteine has been developed. The native PDMS channel was coated with poly(diallyldimethylammonium chloride) (PDDA), and then gold nanoparticles by layer-by-layer technique was assembled on PDDA to immobilize cysteine. The assembly was followed by infrared spectroscopy/attenuated total reflection method, contact angle, EOF measurements and electrophoretic separation methods. EOF of this channel can be reversibly switched by varying the pH of running buffer. At low pH, the surface of channels is positively charged, EOF is from cathode to anode. At high pH, the surface is negatively charged, EOF is from anode to cathode. At pH 5.0, near the isoelectric point of the chemisorbed cysteine, the surfaces of channels show neutral. When pH is above 6.0 or below 4.0, the magnitude of EOF varies in a narrow range. And the modified channel surface displayed high reproducibility and good stability, a good reversibility of cathodic–anodic EOF transition under the different pH conditions was observed. Separation of dopamine and epinephrine as well as arginine and histidine were performed on the modified chip. [Copyright &y& Elsevier]