Search

Detection of alpha-l-fucosidase has been shown to have relevance in diagnosing hepatocellular carcinoma. Few assays have been developed to measure this enzyme, with most relying on colorimetric techniques involving the enzyme's kinetics. While these assays are facile and quick, the sensitivity is not always sufficient for early tumor detection. To improve upon previous assays for alpha-l-fucosidase, a fluorescence based immunoassay was produced implementing an alpha-l-fucosidase specific antibody (FUCA2). The immobilization of the alpha-l-fucosidase-specific antibody onto a quartz slide was investigated with several bioconjugation approaches and an immunoassay for detection of alpha-l-fucosidase was produced. The immunoassay was utilized to produce calibration curves for quantifying alpha-l-fucosidase concentrations in both PBS and human blood serum. A detection limit of 10 nM was found using human blood serum, which is well below the diagnostic cutoff point of 80 nM. [ABSTRACT FROM AUTHOR]

Alpha-l-fucosidase is a known biomarker for hepatocellular carcinoma that has shown great potential in diagnostics. Most of the focus for this enzyme has been on the free form found in serum; however, little is known of the properties of the minor portion of membrane-bound alpha-l-fucosidase. To better understand the properties of membrane-bound alpha-l-fucosidase, this enzyme was surveyed at the air-water interface. Alpha-l-fucosidase is able to form a stable Langmuir monolayer, which was confirmed through surface-pressure and surface-potential area isotherms, as well as infrared reflection-absorption spectroscopy (IRRAS). Furthermore, an interaction between the alpha-l-fucosidase Langmuir monolayer and a specific antibody for this enzyme, FUCA2, was observed. [ABSTRACT FROM AUTHOR]

Highlights: [•] Surface anchoring groups vary with CNT diameter and surface area. [•] Pt loading increases with the decreasing CNT diameter. [•] Pt size decreases with the increasing CNT diameter. [•] The ORR performance of Pt/CNTs increases with the increasing CNT diameter. [ABSTRACT FROM AUTHOR]

The present article reports on a simple, economical, and green preparative strategy toward water-soluble, fluorescent carbon nanopartides (CPs) with a quantum yield of approximately 6.9% by hydrothermal process using low cost wastes of pomelo peel as a carbon source for the first time. We further explore the use of such CPs as probes for a fluorescent Hg2+ detection application, which is based on Hg2+- induced fluorescence quenching of CPs. This sensing system exhibits excellent sensitivity and selectivity toward Hg2+, and a detection limit as low as 0.23 nM is achieved. The practical use of this system for Hg2+ determination in lake water samples is also demonstrated successfully. [ABSTRACT FROM AUTHOR]

An efficient and novel method for the synthesis of a series of 11-aryl-10,12-dihydrodiindino[1,2-b',2',1'-e]pyridine via one-pot multicomponent reactions of aldehydes, indan-1-one and ammonium acetate has been delineated. All prepared compounds were structurally elucidated by IR, UV-Vis, 1H and 13C NMR and X-ray diffraction techniques. The molecules adopted monoclinic crystal system with P21/c space group and almost similar unit cell dimensions. The X-ray molecular geometries of the studied compounds were in excellent agreement with those computed by B3LYP/6-311++G(d,p) level of theory. The energies of the frontier orbitals calculated by B3LYP/6311++G(d,p) level of theory enabled monitoring the reactivity and stability of the title molecules. The non-linear optical properties (NLO) and pNA were also computed and discussed. Compounds have shown broad spectrum cytotoxic activity against some human tumour cell lines; two of them rendering the most profound effect. [ABSTRACT FROM AUTHOR]

Protected amino/peptide thioacids have been synthesized in pure form in excellent yields and with retention of chirality by using protected aminoacyl- and peptidoylbenzotriazoles as active intermediates. [ABSTRACT FROM AUTHOR]

This study investigates the surface chemistry properties of the tyrosinase enzyme Langmuir monolayer at air-aqueous interface using sodium chloride in the subphase to induce the surface activity of the enzyme. Investigation of surface packing and stability of the tyrosinase Langmuir monolayer were performed using surface chemistry experiments while spectroscopic analysis was done to study enzyme conformation. It was found that the tyrosinase enzyme forms a fluid film at air-aqueous interface with good stability as shown by compression-decompression cycles experiments and stability measurements at various surface pressures. UV-vis absorption and fluorescence measurements at different surface pressures revealed that the Langmuir monolayer has good homogeneity with no evidence of aggregates during compression. To gain insight on the conformation of tyrosinase Langmuir monolayer p-polarized infrared-reflection absorption spectroscopy was used. It was found that at high surface pressures the predominant secondary structures were β-sheets while at lower surface pressure both α -helices and β-sheets were present. The circular dichroism spectra were obtained by transferring the Langmuir monolayer at 10 mN.m−1 to a solid quartz support (Langmuir-Blodgett film, LB film), which showed that the major conformation present were α-helices. Images from the immobilized LB films were obtained using atomic force microscopy which showed homogenous and regular deposition with a mean thickness ranging from 3 to 4 nm. [ABSTRACT FROM AUTHOR]

Abstract Hepatocellular carcinoma (HCC) is among the leading causes of mortality in the world. The detection of HCC in its early stage is the key for early treatment and thus the improvement of the chances of survival. Among the various methods of HCC screening, assays based on the detection of biomarker that is specific to HCC such as alpha- l -fucosidase (AFU) have been regarded as the most prominent methods. In this regards, a new assay for the detection of AFU to screen HCC was developed. This assay was based on the energy transfer between carbon dots (C-dots) and gold nanoparticles (AuNPs), the concentration of AFU could be monitored by the degree of C-dots fluorescence quenching due to the energy transfer. With this assay, a limit of detection of 3.4 nM (well below the diagnostic cutoff point of 80 nM), and a broad linear range of detection from 11.3 to 200 nM were achieved. We also demonstrate the determination of the concentration of AFU in human blood serum. Graphical abstract Image 1 Highlights • Energy transfer between carbon dots and AuNPs was used to design assay for the detection of alpha- l -fucosidase. • A sandwich assay was designed by combining polyclonal antibody coated AuNPs with monoclonal antibody attached to carbon dots. • A limit of detection of 3.4 nM and linear range from 11.3 to 200 nM were achieved. [ABSTRACT FROM AUTHOR]

The interface of nucleic acids and nanomaterials is among the most promising fields in recent years. Considerable efforts have been devoted to the development of novel systems based on the two components for various promising applications such as sensing, bioimaging, drug delivery, and theranostics. However, the determination of nucleic acid concentration in these systems remains as a challenge due to the interference of nanoparticles. To this end, we developed a simple, yet reliable, method to quantify the nucleic acid concentration in their nanoparticle or polymer conjugates based on circular dichroism (CD) spectroscopy. In this paper, three nucleic acids, namely, DNA sodium salt from calf thymus (NaDNA), DNA from herring sperm (hsDNA), and ribonucleic acid from torula yeast (tyRNA), were noncovalently conjugated to three nanoparticles. The concentrations of the three nucleic acids in their nanoparticle conjugates were successfully determined on the basis of CD spectra calibration curves. [ABSTRACT FROM AUTHOR]

Carbon dots, a recent member of the renowned carbon-based nanomaterials family, have attracted significant interest from various fields. The extraordinary properties, including excellent photoluminescence, high biocompatibility, and tunable surface functionalities as well as the abundant and inexpensive nature, have led to remarkable bioapplications in bioimaging, drug delivery, and theranostics development. In this article, studies on the interaction of C-dots with biomacromolecules are reviewed first, and recent developments of C-dots for target-specific bioimaging, drug delivery as well as theranostics development are highlighted and discussed. [ABSTRACT FROM AUTHOR]

Fe/N/C catalysts are very active for the oxygen reduction reaction (ORR); however, the nature of the active site(s) is not fully understood. In this work, we study the performance of different types of N/C and Fe/N/C catalysts for the ORR, and the effect of the addition of NaCN. Phthalocyanine and graphene have been studied as model metal-free catalysts for the ORR. Fe-phthalocyanine (FePhcy), Fe-phthalocyanine dispersed in graphene (FePhcy/G) and Fe/N/G, have been used as model Fe-containing catalysts. FePhcy and FePhcy/G only contain Fe atoms coordinated to 4 nitrogen atoms. On the other hand, different species such as Fe-Nx and Fe 3 C coexist in Fe/N/G. In addition, C C ensembles are present in the graphene present in FePhcy/G and Fe/N/G. The ORR activity is characteristic of each catalyst, being the highest for the catalysts containing FeN 4 ensembles. The addition of CN − results in the selective poisoning of the Fe-containing sites but it does not suppress the ORR activity of the Graphene containing samples. In-situ infrared spectroscopy studies during the ORR reveal that CN − poisoning of the Fe sites is reversible, desorbing at potentials less positive than ca. 600 mV. As a consequence, the ORR activity of the Fe-containing sites is recovered gradually. [ABSTRACT FROM AUTHOR]

Peptides and proteins have become very promising drug candidates in recent decades due to their unique properties. However, the application of these drugs has been limited by their high enzymatic susceptibility, low membrane permeability and poor bioavailability when administered orally. Considerable efforts have been made to design and develop drug delivery systems that could transport peptides and proteins to targeted area. Although it is of great importance to determine the composition after loading a drug to the carrier, the ability to do so is significantly limited by current analytical methods. In this letter, five important proteins, α 1 -antitrypsin, hemoglobin human, human serum albumin, human transferrin and r-globulin were chemically conjugated to two model drug carriers, namely carbon dots and polymer O-(2-carboxyethyl) polyethylene glycol. A simple yet convenient method based on circular dichroism spectroscopy was developed to determine the compositions of the various protein-carrier conjugates. [ABSTRACT FROM AUTHOR]

The current work deals with the mixed micellization phenomena of surface active promazine hydrochloride (PMZ) drug with cationic hydrotropes (para-toluidine hydrochloride and ortho-toluidine hydrochloride) in absence and occurrence of 50 mmol kg 1 NaCl at five different temperature (293.15-313.15 K). PMZ is an amphiphilic phenothiazine drug and employed for the cure of mania and schizophrenia. Conductometry measurement was employed to gain a detailed picture of the interactions between drug and hydrotrope molecules. The experimental data were analyzed according to different mixing models within the outline of the pseudophase separation model. The evaluated values of critical micelle concentration (cmc) were found to be inferior than cmcid values signifying attractive interactions involving the both components in the solutions. NaCl further reduces the cmc of pure amphiphiles and their mixed systems as a result of screening of the electrostatic repulsion between the polar head groups. The micellar mole fractions (X1) of hydrotropes evaluated by various proposed models were constantly more than ideal values (Xid 1) signifying high involvements of hydrotrope in mixed micelles. Activity coefficients (fRub 1 and fRub 2) were always below one in all cases signifying synergism in mixed micelles. Thermodynamic parameters favor the process of micellization which is found to be entropy driven. The negative values of free energies of mixing demonstrated the stability of the mixed systems of drug and hydrotrope. [ABSTRACT FROM AUTHOR]

The fate of organic pollutants in the environment is influenced by several factors including the type and strength of their interactions with soil components especially SOM. However, a molecular level answer to the question “How organic pollutants interact with SOM?” is still lacking. In order to explore mechanisms of this interaction, we have developed a new SOM model and carried out molecular dynamics (MD) simulations in parallel with sorption experiments. The new SOM model comprises free SOM functional groups (carboxylic acid and naphthalene) as well as SOM cavities (with two different sizes), simulating the soil voids, containing the same SOM functional groups. To examine the effect of the hydrophobicity on the interaction, the organic pollutants hexachlorobenzene (HCB, non-polar) and sulfanilamide (SAA, polar) were considered. The experimental and theoretical investigations explored four major points regarding sorption of SAA and HCB on soil, yielding the following results. 1—The interaction depends on the SOM chemical composition more than the SOM content. 2—The interaction causes a site-specific adsorption on the soil surfaces. 3—Sorption hysteresis occurs, which can be explained by inclusion of these pollutants inside soil voids. 4—The hydrophobic HCB is adsorbed on soil stronger than the hydrophilic SAA. Moreover, the theoretical results showed that HCB forms stable complexes with all SOM models in the aqueous solution, while most of SAA–SOM complexes are accompanied by dissociation into SAA and the free SOM models. The SOM-cavity modeling had a significant effect on binding of organic pollutants to SOM. Both HCB and SAA bind to the SOM models in the order of models with a small cavity > a large cavity > no cavity. Although HCB binds to all SOM models stronger than SAA, the latter is more affected by the presence of the cavity. Finally, HCB and SAA bind to the hydrophobic functional group (naphthalene) stronger than to the hydrophilic one (carboxylic acid) for all SOM models containing a cavity. For models without a cavity, SAA binds to carboxylic acid stronger than to naphthalene. [ABSTRACT FROM AUTHOR]

Abstract: In this communication, we report on the solvothermal preparation of spinel ZnCo2O4/N-doped carbon nanotube (ZnCo2O4/NCNT) composite. As a novel oxygen reduction reaction (ORR) electrocatalyst, the ZnCo2O4/NCNT composite shows high activity via a four-electron pathway in alkaline solution. Such catalyst also exhibits superior methanol tolerance ability and durability over commercial Pt/C catalyst. [Copyright &y& Elsevier]

Abstract: In this paper, we demonstrate the first use of BCNO nanoparticles (BCNO NPs) as a novel highly efficient fluorosensor for Cu2+ detection with high selectivity. The detection process is ultrafast and can be completed within 2min, and the detection limit is 0.1μM. We also show the practical use of this sensor for Cu2+ determination in real water samples. [Copyright &y& Elsevier]

Abstract: Poly(o-anisidine) (POAS)/silverized multiwall carbon nanotubes (POAS–MWCNTs/Ag) composite was prepared by adsorption of POAS on the surface of MWCNTs by solution method. This research demonstrated that it was possible to metalized MWCNTs and uses a polymer as a substitute for polyaniline (PANI) to synthesize MWCNTs/conducting polymer nanocomposites by one-step easy mixing of solutions. The resulting composite was characterized using SEM; TGA and fourier transform infrared spectroscopy (FTIR), X-ray spectroscopy. The electrical resistivity of the composites was studies and it was found unusually higher conductivity than that of pure POAS and MWCNTs and it was 5S/cm. All the results demonstrated a facile route to the synthesis of POAS–MWCNTs/Ag composites, possessing good electrical conductivity and outstanding thermal stability at high temperature. [Copyright &y& Elsevier]

Abstract: In this article, for the first time, two-dimensional hybrid mesoporous Fe2O3–graphene (mFe2O3–G) nanostructures were developed as a peroxidase mimetic with catalytic activities superior to those of mFe2O3, G, and previously reported Fe-based peroxidase mimetics. The high-surface-area mFe2O3 not only offers a large number of catalytically active sites, but also facilitates the diffusion of 3,3,5,5-tetramethylbenzidine (TMB) and H2O2 toward G surface. On the other hand, G is π-rich and thus favors the adsorption and enrichment of TMB within these pores. These synergistic effects lead to highly improved catalytic performances. Based on these findings, a simple, rapid, and highly sensitive and selective optical detector of glucose has been developed and demonstrated in buffer solution with a pretty low detection limit of 0.5μM. In addition, this nanosensor is reusable and can also be used for glucose detection in diluted serum. [Copyright &y& Elsevier]

Abstract: In this paper, a novel and highly sensitive DNA sensor based on biopolymer is presented. This polydopamine nanospheres-based sensing platform exhibits high selectivity and sensitivity with a detection limit of 5nM and the sensitivity of this sensing platform increases with increased temperature. [Copyright &y& Elsevier]

Abstract: In this communication, for the first time, we demonstrate the electrodeposition of Ni3S2 on ZnO (ZnO@Ni3S2) array supported on nickel foam. We further demonstrate the direct use of ZnO@Ni3S2 array as a binder-free electrode material for supercapacitors and this electrode exhibits a very high specific capacitance of 1529 F g−1 at a current density of 2 A g−1, good rate capability and cycling stability. [Copyright &y& Elsevier]

A convenient synthesis of chiral N-, O-, and S-acyl monoiso- and diisopeptides from di- and tripeptides containing tryptophan, tyrosine, and cysteine units using benzotriazole is reported in solution phase. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we demonstrate the preparation of reduced graphene oxide (rGO) decorated with FeF3 nanoparticles (FeF3NPs) by adding FeF3 aqueous solution to the rGO ethanol/water dispersion. The obtained FeF3/rGO nanocomposite is further tested as a cathode material for rechargeable lithium batteries and found to have high discharge capacities, good rate capabilities and cycling performance. It can deliver a high discharge capacity of 476mAhg−1 at a current density of 50mAg−1 in the voltage range 1.0–4.5V. It still delivers a discharge capacity of 146mAhg−1 with 81% capacity retention after 50 charge–discharge cycles under a current density of 1000mAg−1 in the voltage range 1.7–4.5V. [Copyright &y& Elsevier]

In this paper, for the first time, we report on the growth of ultrathin Ni(OH)2 nanosheet arrays on a nickel foam (NF) via a novel pH-driven dissolution–precipitation route, carried out by a hydrothermal treatment of the NF in an acidic medium without the introduction of other nickel sources. Acid etching of the NF surface leads to nano-pits and produces Ni(H2O)n2+ ions at the early stage of the reaction. With the elapsed time, an increase in the pH level occurs and the Ni(H2O)n2+ ions gradually hydrolyze and preferentially precipitate on the nano-pits, serving as nucleation sites and leading to ultrathin Ni(OH)2 nanosheet arrays on an NF. The effects of the experimental parameters, such as reaction time, acid type and starting pH value, on the Ni(OH)2 growth are also investigated. Because the nano-pits are integrated parts of the NF and the deposition of Ni(OH)2 nanosheets on such nano-pits ensures intimate contact between them, the Ni(OH)2/NF is robust enough to withstand a violent sonication process and efficient and rapid electron transfer is achieved. As a binder-free anode for Li-ion batteries, the Ni(OH)2/NF exhibits an unexpected ultrahigh capacity of 1689 mA h g−1 and excellent cycling stability. [ABSTRACT FROM AUTHOR]

Abstract: The present communication reports on the preparation of N-doped carbon nanotubes (NCNTs) by pyrolysis of FeCl3 and methyl orange (MO) co-doped functional tubular polypyrrole (PPy). As an oxygen reduction reaction (ORR) catalyst, NCNT-800 obtained at 800°C exhibits high catalytic activity comparable to commercial Pt/C catalyst with superior methanol tolerance ability and durability in alkaline conditions. [Copyright &y& Elsevier]

The present communication reports on a facile one-step solvothermal synthesis of highly crystallized MoS 2/TiO 2 nanocomposites for the first time. The TEM image shows the generation of a large amount of TiO 2 nanoparticles with diameters in the range of 5–8 nm. The photocurrent measurement suggests that loading a certain amount of MoS 2 can effectively improve separation of photogenerated carries. Cyclic voltammograms measurements reveal that TiO 2 modified with 1.0 wt% MoS 2 can reduce hydrogen reduction overpotential, thereby leading to enhanced photocatalytic activity. Photocatalytic H 2 evolution test suggests that 1.0 wt% MoS 2/TiO 2 nanocomposites show superior photocatalytic activity, and the H 2 production rate achieves 119.5 μmol h −1 g −1 and is about 19 times higher than that of TiO 2 alone, which could be attributed to the short diffusion distance in TiO 2 nanoparticles, efficient interfacial electron transfer from TiO 2 nanoparticles to MoS 2 surface, and reduced hydrogen reduction overpotential. Furthermore, the MoS 2/TiO 2 photocatalysts are stabile during the photocatalytic H 2 evolution test. Graphical abstract: [Figure not available: see fulltext.]. [ABSTRACT FROM AUTHOR]

Abstract: The present communication reports on the first electrodeposition of Ni(OH)2 on ZnO array supported on Ni foam. When applied as a binder-free electrode material for pseudocapacitive energy storage, the resulting ZnO@Ni(OH)2 array exhibits a high specific capacitance of 2028Fg−1 at a current density of 10Ag−1 with good cycling stability. Meanwhile, the array exhibits a superb rate capability. Even at an extremely high current density of 100Ag−1, the array still shows a very high specific capacitance of 1059Fg−1. [Copyright &y& Elsevier]

Abstract: The present communication reports on the first preparation of Ni(OH)2 nanoflakes array on Ni foam, carried out by hydrothermal treatment of Ni foam in acidic medium without the presence of extra nickel salt. We further demonstrate the application of such Ni(OH)2/Ni foam as a binder-free electrode material for supercapacitors. It is found that it can deliver high capacities of 1228F/g and 918F/g at 5A/g and 30A/g, respectively, with excellent cycling stability. [Copyright &y& Elsevier]

Open-chain N-Cbz-protected-peptidoyl benzotriazolides are converted by a novel lactamization strategy using proline as a turn introducer into both symmetrical (5a-c and 11a-c) and unsymmetrical (19a-e) bis-2,5-diketopiperazines (bis-2,5-DKPs), previously recognized as difficult targets. [ABSTRACT FROM AUTHOR]

Abstract: In this communication, for the first time, we demonstrate the fast and facile preparation of porous FeF3 nanospheres using solvent exchange from FeF3 aqueous solution to ethanol. We further demonstrate the use of such FeF3 nanospheres as cathode materials for rechargeable lithium-ion batteries with good rate capability and cycling performance. [Copyright &y& Elsevier]

Abstract: The article reports on the microwave-assisted rapid green synthesis of photoluminescent carbon nanodots (C-dots) with diameters in the range of 1–4nm using flour as the carbon source. It suggests that the resultant C-dots exhibit high sensitivity and selectivity toward Hg2+ with a detection limit as low as 0.5nM and a linear range of 0.0005–0.01μM. The practical use of this system for Hg2+ determination in real lake water samples is also demonstrated successfully. [Copyright &y& Elsevier]

Abstract: The present communication demonstrates the first environmentally friendly hydrothermal synthesis of nickel sulfide nanospheres/reduced graphene oxide (nickel sulfides/rGO) nanocomposites with the use of l-cysteine as a reducing agent, sulfur donor, and linker. The nanosphere consists of ultrafine particles leading to textural pores. The resulting nickel sulfides/rGO nanocomposites were further used as an electrode material for supercapacitors and found to exhibit very high specific capacitances of 1169Fg−1 and 761Fg−1 at current rates of 5Ag−1 and 50Ag−1, respectively, with good cycling stability. [Copyright &y& Elsevier]

Abstract: The present communication reports on the first preparation of porous tubular C/MoS2 nanocomposites using porous anodic aluminum oxide as a template. We further demonstrate the application of such composites as a novel electrode material for supercapacitors. It is found that they can deliver a high capacitance of 210F/g at 1A/g and exhibit excellent long-term cycling stability over 1000 cycles. [Copyright &y& Elsevier]

A highly efficient fluorosensor based on ultrathin graphitic carbon nitride (g-C3N4) nanosheets for Cu2+ was developed. In the absence of metal ions, the nanosheets exhibit high fluorescence; the strong coordination of the Lewis basic sites on them to metal ions, however, causes fluorescence quenching via photoinduced electron transfer leading to the qualitative and semiquantitative detection of metal ions. This fluorosensor exhibits high selectivity toward Cu2+. The whole detection process can be completed within 10 min with a detection limit as low as 0.5 nM. The use of test paper enables the naked-eye detection of Cu2+ with a detection limit of 0.1 nmol. The practical use of this sensor for Cu2+ determination in real water samples was also demonstrated. [ABSTRACT FROM AUTHOR]

Abstract: The carbon nitride dots (CNDs) can serve as an effective stabilizing agent for reduced graphene oxide (GO) prepared by chemical reduction using hydrazine hydrate as the reducing agent. Physicochemical characterization with a combination of techniques including UV–vis spectroscopy, Raman spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy indicate the preparation of aqueous dispersion of rGO and the formation of CNDs–rGO hybrids. We further demonstrate the subsequent self-assembly of the CNDs–rGO with glucose oxidase (GOD) into hybrids, which is confirmed by the scanning electron microscopy and electron energy dispersive spectrum analysis. As a typical application of such materials, a glucose biosensor has been constructed by deposition of the GOD–CNDs–rGO hybrids on the surface of a glassy carbon electrode. The linear detection range and detection limit are estimated to be from 40μM to 20mM (r =0.994) and 40μM at signal-to-noise ratio of 3, respectively. It is further shown that this glucose biosensor can be used for glucose detection in human blood serum. [Copyright &y& Elsevier]

Abstract: The present communication reports on the preparation of WS2 nanoparticles–encapsulated amorphous carbon tubes (WS2NPs/CTs) via two-step processes. Firstly, CTs were grown in anodic aluminum oxide (AAO) film by hydrothermal carbonization of glucose. Secondly, the as-prepared CTs/AAO film was impregnated with (NH4)2WS4 followed by high temperature treatment in Ar atmosphere. We further demonstrate the application of the resulting WS2NP/CT composites as a novel electrode material for supercapacitor. Such composites were found to deliver a specific capacitance of 337F/g at a high current density of 10A/g with good cycle stability. [Copyright &y& Elsevier]

Abstract: We have prepared calcined CuO microsheets (MSs) by a wet-chemical process using reducing agents in alkaline medium and characterized by UV/vis., fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (XRD), and field-emission scanning electron microscopy (FESEM) etc. The detailed structural, compositional, and optical characterizations of the MSs were evaluated by XRD pattern, FT-IR, X-ray photoelectron spectroscopy (XPS), and UV–vis spectroscopy, respectively which confirmed that the obtained MSs are well-crystalline CuO and possessed good optical properties. The CuO MSs morphology was investigated by FESEM, which confirmed that the calcined nanomaterials were sheet-shaped and grown in large-quantity. Here, the efficiency of the CuO MS was applied for a selective adsorption of gold(III) ion prior to its detection by inductively coupled plasma-optical emission spectrometry (ICP-OES). The selectivity of CuO MSs towards various metal ions, including Au(III), Cd(II), Co(II), Cr(III), Fe(III), Pd(II), and Zn(II) was analyzed. Based on the adsorption isotherm study, it was confirmed that the selectivity of MSs phase was mostly towards Au(III) ion. The static adsorption capacity for Au(III) was calculated to be 57.0mgg−1. From Langmuir adsorption isotherm, it was confirmed that the adsorption process was mainly monolayer-adsorption onto a surface containing a finite number of adsorption sites. [Copyright &y& Elsevier]

The present communication reports on the first use of commercially available three-dimensional porous Ni foam (NF) as a novel electrochemical sensing platform for nonenzymatic glucose detection. NF not only acts as a working electrode, but also functions as an effective electrocatalyst for electrooxidation of glucose. The sensor exhibits high selectivity toward glucose. The linear range and limit of detection were 0.05–7.35 mM (R = 0.995) and 2.2 μM with a signal-to-noise ratio of 3, respectively. The application of this glucose sensor in human blood serum has also been demonstrated successfully. [ABSTRACT FROM AUTHOR]

The present paper reports on the facile preparation of novel Ni(ii)-based metal–organic coordination polymer nanoparticle/reduced graphene oxide (NiCPNP/rGO) nanocomposites for the first time. The formation of the nanocomposites occurs in a single step, carried out by hydrothermal treatment of the mixture of tannic acid functioned graphene oxide and NiCl2 aqueous solution in N,N-dimethylformamide. It is found that the NiCPNP/rGO nanocomposite-modified electrode shows high electrocatalytic activity for glucose oxidation in alkaline medium. This nonenzymatic glucose sensor exhibits high selectivity toward glucose and the linear range and limit of detection are estimated to be from 0.01 to 8.75 mM (r: 0.997) and 0.14 μM with a signal-to-noise ratio of 3, respectively. The application of this glucose sensor in human blood serum has also been demonstrated successfully. [ABSTRACT FROM AUTHOR]

Unprotected S-acylated cysteine isopeptides containing α-, β- or γ-amino acid units have been synthesized, and their conversion to native hexapeptides by S- to the N-terminus ligations involving 17-, 18- and 19-membered cyclic transition states have been demonstrated both experimentally and computationally to be more favorable than intermolecular cross-ligations. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we report on one-pot synthesis of Ag nanoparticles/reduced graphene oxide (AgNPs/rGO) nanocomposites by heating mixed solution of graphene oxide (GO) and AgNO3 with the use of diethylenetriamine as a reducing agent at 80°C for 30min. Several analytical techniques including UV–vis spectroscopy, Raman spectroscopy and transmission electron microscopy (TEM) have been employed to characterize the resulting nanocomposites. It was found that such nanocomposites exhibit good catalytic activity toward the reduction of H2O2. This nonenzymatic H2O2 sensor shows a fast amperometric response time of less than 2s. The linear detection range is estimated to be from 0.1 to 100mM (r =0.999), and the detection limit is estimated to be 3.6μM at a signal-to-noise ratio of 3. [Copyright &y& Elsevier]

Abstract: Cobalt doped antimony oxide nano-particles (NPs) have been synthesized by hydrothermal process and structurally characterized by utilizing X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and Fourier transforms infrared spectrophotometer (FT-IR) which revealed that the synthesized cobalt antimony oxides (CoSb2O6) are well crystalline nano-particles with an average particles size of 26±10nm. UV–visible absorption spectra (∼286nm) were used to investigate the optical properties of CoSb2O6. The chemical sensing of CoSb2O6 NPs have been primarily investigated by I–V technique, where dichloromethane is used as a model compound. The analytical performance of dichloromethane chemical sensor exhibits high sensitivity (1.2432μAcm−2 mM−1) and a large linear dynamic range (1.0μM–0.01M) in short response time (10s). The photo catalytic activity of the synthesized CoSb2O6 nano-particles was evaluated by degradation of acridine orange (AO), which degraded 58.37% in 200min. These results indicate that CoSb2O6 nano-particles can play an excellent research impact in the environmental field. [Copyright &y& Elsevier]

The article demonstrates the application of graphene flakes (GFs) as supercapacitors. It discusses the preparation of electrode materials by hydrothermal synthesis. It reports that GFs synthesized through chlorosulfonic acid and hydrogen peroxide exfoliation have been successfully used to synthesize a manganese oxide/GF (MG) composite. It adds that GFs exhibit good conductivity and inhibit the aggregation of the manganese oxide nanosheets.

Abstract: Low-dimensional nanoparticles composed SnO2–Co3O4 nanocubes (NCs) were prepared by a hydrothermal method using reducing agents. The doped nanomaterials were investigated by UV/vis, powder X-ray diffraction, FT-IR, energy-dispersive X-ray spectroscopy (EDS), and Raman spectroscopy, and field-emission scanning electron microscopy. They were deposited on a silver electrode (AgE, surface area, 0.0216cm2) to give a drug sensor with a fast response towards Olmesartan medoxomil (OSM) in 0.1molL−1 phosphate buffer-phases. The sensor also exhibits higher sensitivity, long-term stability, and enhanced electrochemical response. The calibration plot is linear (r 2=0.9948) over the 0.28nmolL−1–1.4μM OSM concentration range. The sensitivity is ∼2.083μAcm−2 mmolL−1 and the detection limit is 0.17nmolL−1 (at an SNR of 3). We discuss the possible potential uses of this nanoparticles doped semiconductor NCs in terms of drug sensing, which could also be employed for the determination of drugs in quality control of formulation. [Copyright &y& Elsevier]

Abstract: Ag nanoparticles-decorated reduced graphene oxide (AgNPs-rGO) has been successfully fabricated through a one-step strategy, carried out by hydrothermal treatment of the mixture of AgNO3 and GO solution under strong alkaline conditions at 180°C for 30min. The reaction was accomplished without extra reducing agent and surface modifier. As-synthesized AgNPs-rGO has been successfully applied in catalytic performance toward the reduction of H2O2. This H2O2 sensor shows a wide linear range of 0.1–60mM (r =0.991) and a low detection limit of 1.80μM at a signal-to-noise ratio of 3. [Copyright &y& Elsevier]

In this work, we develop a novel environmentally friendlystrategy toward one-pot synthesis of CuS nanoparticle-decorated reducedgraphene oxide (CuS/rGO) nanocomposites with the use of l-cysteine, an amino acid, as a reducing agent, sulfur donor, andlinker to anchor CuS nanoparticles onto the surface of rGO sheets.Upon visible light illumination (λ > 400 nm), the CuS/rGOnanocomposites show pronounced enhanced photocurrent response andimproved photocatalytic activity in the degradation of methylene blue(MB) compared to pure CuS. This could be attributed to the efficientcharge transport of rGO sheets and hence reduced recombination rateof excited carriers. [ABSTRACT FROM AUTHOR]

The article focuses on construction of graphene-based ternary organic-inorganic nanocomposites of Porphyrin which is aid by graphene oxide reduction (GO) as it is cheap and produces large-scale reduced graphene oxide (RGO). Porphyrin (P) with Tin (Sn) works as an effective photocatalyst for the reduction of graphene oxide (GO) under visible-light irradiation. It states the photoreduction of gold (Au) catalyzed by Sn-porphyrin (SnP) leads to ternary angular gold (Au) nanoparticles (AuNPs).

Abstract: Ag nanoparticle-decorated TiO2 nanowires (AgNP–TiO2 NWs) have been successfully fabricated through a green photocatalytic process, carried out by irradiating the mixture of AgNO3 solution in ethanol and pre-formed TiO2 NWs under UV light. Such nanocomposites exhibit remarkable catalytic performance toward the reduction of H2O2 and this H2O2 sensor shows a wide linear range of 0.1mM to 60mM (r =0.991) and a low LOD of 1.70μM at a signal-to-noise ratio of 3. [Copyright &y& Elsevier]

This study demonstrates the first synthesis of novel organic/inorganic ternary nanohybrids of tin(IV) prophyrin (SnPor), Ag nanoparticles (AgNPs), and reduced graphene oxide (RGO) by an environmentally friendly phtotcatalytic process using SnPor as a photocatalyst for the reduction of both GO and AgI. The nanohybrids exhibit high photocurrent generation as a result of the photosensitization effect of SnPor and surface plasmon resonance excitation in the AgNPs. Furthermore, in the activity test, the nanohybrids show good catalytic activity in the degradation of rhodamine B under the irradiation of visible light (λ>400 nm) and in the reduction of 4-nitrophenol. The detailed mechanism is discussed in the article. [ABSTRACT FROM AUTHOR]

The article focuses on fast and sensitive colorimetric detection of H[2]O[2] and glucose on the based on polyoxometalate clusters. It states that the application of colorimetric assay to glucose detection both in buffer solution and diluted serum showed that silicotungstic acid (HSiW) catalyzes the oxidation of tetramethylbenzidine (TMB) by H2O2. It also states that this detection system is simple, fast, sensitive, and selective.