Fabrication of Pb-Containing PtAu Nanoflowers via Galvanic Replacement Method for Electrocatalytical Oxidation of Methanol.

A Pb-containing PtAu nanoflower electrocatalyst was deposited on the cathode via galvanic replacement reaction in a double-cabin galvanic cell (DCGC) with a Cu plate as the anode, a multiwalled carbon nanotube (MWCNT) modified glassy carbon electrode (GCE) as the cathode, 0.1 M HClO aqueous solution as the anolyte, and Pb-containing Pt salt and Au salt mixed aqueous solution as the catholyte, respectively, and the electrocatalytic performance of the modified electrode toward methanol oxidation in the alkaline medium was investigated. Electrochemical studies reveal that the stripping of bulk Cu can induce underpotential deposition (UPD) of Pb on Pt during the galvanic replacement reaction, which affects the morphology and composition of Pb-containing PtAu nanoparticles.

Preparation of Gold Nanoparticles via Anodic Stripping of Copper Underpotential Deposition in Bulk Gold Electrodeposition for High-Performance Electrochemical Sensing of Bisphenol A.

Bisphenol A is one of the most widely used industrial compounds. Over the years, it has raised severe concern as a potential hazard to the human endocrine system and the environment. Developing robust and easy-to-use sensors for bisphenol A is important in various areas, such as controlling and monitoring water purification and sewage water systems, food safety monitoring, etc.

Comprehensive Study of an Earth-Abundant Bifunctional 3D Electrode for Efficient Water Electrolysis in Alkaline Medium.

We report efficient electrolysis of both water-splitting half reactions in the same medium by a bifunctional 3D electrode comprising Co3O4 nanospheres nucleated on the surface of nitrogen-doped carbon nanotubes (NCNTs) that in turn are grown on conductive carbon paper (CP). The resulting electrode exhibits high stability and large electrochemical activity for both oxygen and hydrogen evolution reactions (OER and HER). We obtain a current density of 10 mA/cm(2) in 0.

Pro-inflammatory S100A9 Protein as a Robust Biomarker Differentiating Early Stages of Cognitive Impairment in Alzheimer's Disease.

Pro-inflammatory protein S100A9 was established as a biomarker of dementia progression and compared with others such as Aβ(1-42) and tau-proteins. CSF samples from 104 stringently diagnosed individuals divided into five subgroups were analyzed, including nondemented controls, stable mild cognitive impairment (SMCI), mild cognitive impairment due to Alzheimer's disease (MCI-AD), Alzheimer's disease (AD), and vascular dementia (VaD) patients. ELISA, dot-blotting, and electrochemical impedance spectroscopy were used as research methods.

Small palladium islands embedded in palladium-tungsten bimetallic nanoparticles form catalytic hotspots for oxygen reduction.

The sluggish kinetics of the oxygen reduction reaction at the cathode side of proton exchange membrane fuel cells is one major technical challenge for realizing sustainable solutions for the transportation sector. Finding efficient yet cheap electrocatalysts to speed up this reaction therefore motivates researchers all over the world. Here we demonstrate an efficient synthesis of palladium-tungsten bimetallic nanoparticles supported on ordered mesoporous carbon.

The role of pro-inflammatory S100A9 in Alzheimer's disease amyloid-neuroinflammatory cascade.

Pro-inflammatory S100A9 protein is increasingly recognized as an important contributor to inflammation-related neurodegeneration. Here, we provide insights into S100A9 specific mechanisms of action in Alzheimer's disease (AD). Due to its inherent amyloidogenicity S100A9 contributes to amyloid plaque formation together with Aβ.

Synthesis of palladium/helical carbon nanofiber hybrid nanostructures and their application for hydrogen peroxide and glucose detection.

We report on a novel sensing platform for H2O2 and glucose based on immobilization of palladium-helical carbon nanofiber (Pd-HCNF) hybrid nanostructures and glucose oxidase (GOx) with Nafion on a glassy carbon electrode (GCE). HCNFs were synthesized by a chemical vapor deposition process on a C60-supported Pd catalyst. Pd-HCNF nanocomposites were prepared by a one-step reduction free method in dimethylformamide (DMF).

Formation of nitrogen-doped graphene nanoscrolls by adsorption of magnetic γ-Fe2O3 nanoparticles.

Graphene nanoscrolls are Archimedean-type spirals formed by rolling single-layer graphene sheets. Their unique structure makes them conceptually interesting and understanding their formation gives important information on the manipulation and characteristics of various carbon nanostructures. Here we report a 100% efficient process to transform nitrogen-doped reduced graphene oxide sheets into homogeneous nanoscrolls by decoration with magnetic γ-Fe2O3 nanoparticles.

Formation of active sites for oxygen reduction reactions by transformation of nitrogen functionalities in nitrogen-doped carbon nanotubes.

Heat treating nitrogen-doped multiwalled carbon nanotubes containing up to six different types of nitrogen functionalities transforms particular nitrogen functionalities into other types which are more catalytically active toward oxygen reduction reactions (ORR). In the first stage, the unstable pyrrolic functionalities transform into pyridinic functionalities followed by an immediate transition into quaternary center and valley nitrogen functionalities. By measuring the electrocatalytic oxidation reduction current for the different samples, we achieve information on the catalytic activity connected to each type of nitrogen functionality.

Neuroprotective and nootropic drug noopept rescues α-synuclein amyloid cytotoxicity.

Parkinson's disease is a common neurodegenerative disorder characterized by α-synuclein (α-Syn)-containing Lewy body formation and selective loss of dopaminergic neurons in the substantia nigra. We have demonstrated the modulating effect of noopept, a novel proline-containing dipeptide drug with nootropic and neuroprotective properties, on α-Syn oligomerization and fibrillation by using thioflavin T fluorescence, far-UV CD, and atomic force microscopy techniques. Noopept does not bind to a sterically specific site in the α-Syn molecule as revealed by heteronuclear two-dimensional NMR analysis, but due to hydrophobic interactions with toxic amyloid oligomers, it prompts their rapid sequestration into larger fibrillar amyloid aggregates.

Magnetically enhanced cytotoxicity of paramagnetic selenium-ferroferric oxide nanocomposites on human osteoblast-like MG-63 cells.

We use quartz crystal microbalance (QCM), 3-(4,5-dimethylthizaol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and fluorescence/optical microscopic inspections to investigate the cytotoxicity of paramagnetic selenium-ferroferric oxide (Se-Fe(3)O(4)) nanocomposites on human osteoblast-like MG-63 cells. The nearly spherical Se-Fe(3)O(4) nanocomposites of 40-50nm diameter, as characterized by transmission electron microscopy (TEM), are synthesized through reduction of selenious acid by ascorbic acid in the presence of nanosized Fe(3)O(4). The QCM technique is employed for the first time to monitor the toxicity of Se-Fe(3)O(4) on tumor cells in a real-time manner.

Development of cationic colloidal silica-coated magnetic nanospheres for highly selective and rapid enrichment of plasma membrane fractions for proteomics analysis.

PM (plasma membrane) proteins play critical roles in many biological processes and are often used as molecular targets for drug discovery. In PM proteome research, fast and highly selective methods for PM preparation are highly desirable for efficient PM protein identification. In the present study, an improved PM isolation technique involving coating intact cells with synthesized cationic silica-coated magnetic nanospheres was developed and applied to the proteomic analysis of the PM from human erythroleukaemia K562 cells.

In vitro study on the individual and synergistic cytotoxicity of adriamycin and selenium nanoparticles against Bel7402 cells with a quartz crystal microbalance.

Selenium nanoparticles (Se NPs) were prepared based on the reduction of selenious acid (H(2)SeO(3)), by employing sodium alginate (SA) as a template. The real-time monitoring of the drug-inducing apoptosis process of human hepatic cancer cells Bel7402 was performed with the quartz crystal microbalance (QCM) measurement. The anti-tumor effect of adriamycin (ADM) used in combination with Se NPs was investigated.

Dynamic measurement of the surface stress induced by the attachment and growth of cells on Au electrode with a quartz crystal microbalance.

The processes of adhesion, spreading and proliferation of human mammary cancer cells MCF-7 on two Au electrodes with different surface roughness (R(f) and R(f)=3.2 or 1.1) were monitored and clearly identified with the quartz crystal microbalance (QCM) technique.

Real-time monitoring of the cell agglutination process with a quartz crystal microbalance.

The real-time monitoring of the agglutination process of human hepatic normal cells (L-02) at the quartz crystal microbalance (QCM) gold (Au) electrode was performed. Two lectins, concanavalin A (Con A) and wheat germ agglutinin (WGA), induced the cell agglutination, resulting in the different Deltaf(0) and DeltaR(1) responses from those caused by the normal cell attachment and growth. The cell-Con A-cell aggregates had higher affinity for the Au substrate due to the excellent adsorption ability of Con A, which was revealed by increased Deltaf(0) and DeltaR(1) shifts and the obvious mass effect of QCM.

The preparation and characterization of poly(o-phenylenediamine)/gold nanoparticles interface for immunoassay by surface plasmon resonance and electrochemistry.

The poly-o-phenylenediamine (PoPD) nonconducting film and gold nanoparticles (AuNPs) were combined to fabricate AuNPs/PoPD film, which is used as a novel biocompatible interface for the immobilization of antibody and develop a simple and sensitive label-free immunoassay for the detection of the related antigen (human immunoglobulin G (IgG)). Surface plasmon resonance (SPR) and electrochemical methods were used to provide the real-time information about the polymer film growth, assembling of various sizes of gold nanoparticles, anti-human IgG antibody (anti-hIgG) immobilization and the antigen-antibody interaction. The microstructures of the PoPD and AuNPs/PoPD films were characterized by atomic force microscopy (AFM).

Electrodeposition of carbon nanotubes-chitosan-glucose oxidase biosensing composite films triggered by reduction of p-benzoquinone or H2O2.

We report here on the electroreduction of p-benzoquinone (BQ) or H2O2 as a new trigger for simple, fast, uniform, and controllable electrodeposition of chitosan (CS) hydrogels and biosensing nanocomposite films of CS, multiwalled carbon nanotubes (MWCNTs), and glucose oxidase (GOD). The multiparameter electrochemical quartz crystal microbalance (EQCM) based on crystal electroacoustic impedance analysis was used to dynamically monitor the deposition processes. When the EQCM Au electrode was immersed in a weakly acidic solution (here pH 5.

Simultaneous quartz crystal microbalance-electrochemical impedance spectroscopy study on the adsorption of anti-human immunoglobulin G and its immunoreaction at nanomaterial-modified Au electrode surfaces.

The quartz crystal microbalance method (QCM), in combination with electrochemical impedance spectroscopy (EIS), has been utilized to monitor in situ anti-human IgG adsorption on several Au-based surfaces, bare Au, nanogold/4-aminothiophenol (4AT)/Au, and multi-walled carbon nanotubes (MWCNT)/Au, and succeeding human IgG reactions. Also, the immobilization protocol of anti-human IgG via its glutaraldehyde (GA) cross-linking with self-assembled 4AT on an Au electrode and the subsequent surface immunoreaction were examined. The resonant frequency (f(0)) and the motional resistance (R(1)) of the piezoelectric quartz crystal (PQC) as well as electrochemical impedance parameters were measured and discussed.

Electrochemical quartz crystal impedance and fluorescence quenching studies on the binding of carbon nanotubes (CNTs)-adsorbed and solution rutin with hemoglobin.

Electrochemical quartz crystal impedance (QCI) technique was utilized to monitor in situ the adsorption of rutin (RT) onto a carbon nanotubes (CNTs)-modified gold electrode and to study the binding process of solution hemoglobin (Hb) to RT immobilized on the electrode. Time courses of the QCI parameters including crystal resonant frequency were simultaneously obtained during the RT adsorption and Hb-RT binding. In contrast to the negligible RT adsorption at a bare gold electrode, the modification by CNTs notably enhanced the amount of adsorption, and almost all of the adsorbed RT molecules were found to be electroactive.