The Experts below are selected from a list of 11433 Experts worldwide ranked by ideXlab platform

Mikko Ritala - One of the best experts on this subject based on the ideXlab platform.

  • low temperature atomic layer deposition of al2o3 thin coatings for corrosion protection of steel surface and Electrochemical Analysis
    Corrosion Science, 2011
    Co-Authors: Belen Diaz, Emma Harkonen, Jolanta światowska, Vincent Maurice, Antoine Seyeux, Philippe Marcus, Mikko Ritala
    Abstract:

    Abstract ToF-SIMS, XPS, voltammetry and EIS investigation of the anti-corrosion properties of thin (10, 50 and 100 nm) alumina coatings grown by atomic layer deposition at 160 °C on steel is reported. Surface Analysis shows a thickness-independent Al 2 O 3 stoichiometry of the coating and trace contamination by the growth precursors. The buried coating/alloy interface has iron oxide formed in ambient air and/or resulting from the growth of spurious traces in the initial stages of deposition. Electrochemical Analysis yields an exponential decay of the coating porosity over four orders of magnitude with increasing thickness, achieved by sealing of the more defective first deposited 10 nm.

Hyun C Yoon - One of the best experts on this subject based on the ideXlab platform.

  • multienzyme modified biosensing surface for the Electrochemical Analysis of aspartate transaminase and alanine transaminase in human plasma
    Analytical and Bioanalytical Chemistry, 2011
    Co-Authors: Seung Yeon Song, Hyun C Yoon
    Abstract:

    We investigated the Electrochemical detection of aspartate transaminase (AST) and alanine transaminase (ALT) by using a multienzyme-modified electrode surface. Determination of the activities of transaminases in human serum is clinically significant because their concentrations and ratios indicate the presence of hepatic diseases or myocardial dysfunction. For Electrochemical detection of AST and ALT, enzymes that participate in the reaction mechanism of AST and ALT, such as pyruvate oxidase (POX) and oxaloacetate decarboxylase, were immobilized on an electrode surface by using an amine-reactive self-assembled monolayer and a homobifunctional cross-linker. In the presence of suitable substrates such as l-aspartate (l-alanine) and α-ketoglutarate, AST and ALT generate pyruvate as an enzymatic end product. To determine the activities of AST and ALT, electroanalyses of pyruvate were conducted using a POX and ferrocenemethanol electron shuttle. Anodically generated oxidative currents from multienzyme-mediated reactions were correlated to AST and ALT levels in human plasma. On the basis of the Electrochemical Analysis, we obtained calibration results for AST and ALT concentrations from 7.5 to 720 units/L in human plasma-based samples, covering the required clinical detection range.

Raheleh Mohammadpour - One of the best experts on this subject based on the ideXlab platform.

  • Reproducible Electrochemical Analysis of nanostructured Cu2O using a non-aqueous 3-methoxypropionitrile-based electrolyte
    Electrochemistry Communications, 2018
    Co-Authors: Leyla Shooshtari, A. Iraji Zad, Raheleh Mohammadpour
    Abstract:

    Cu2O is an attractive material in terms of semiconducting properties and is considered a leading candidate in all-oxide photovoltaics. Electrochemical Analysis of Cu2O, including Mott-Schottky (MS) and impedance spectroscopy (IS), provides a wealth of data on charge carriers, Fermi level and interface properties. MS and IS are usually measured in aqueous solutions. However, Cu2O is easily reduced or oxidized to Cu or CuO in aqueous solutions, the layer peels off after the Analysis and there is a small voltage window for the tests. In some cases, an anti-corrosive n-type barrier layer is employed on top of the bare Cu2O electrode to make the measurement possible, which could result in deviation from actual values. Here we introduce a non-aqueous electrolyte based on tetrabutylammonium-tetrafluoroborate in 3-methoxypropionitrile for Electrochemical Analysis of Cu2O. MS Analysis shows reproducible results in terms of dopant density and flat band potential, while the Analysis in aqueous (0.5 M Na2SO4) electrolyte shows inconsistent, irreproducible results. In the case of IS, the transport resistivity of the layers was evaluated using the new electrolyte and shows a linear trend with thickness, as expected. The proposed non-aqueous electrolyte can potentially be used for the Electrochemical Analysis of other sensitive semiconductors.

  • Reproducible Electrochemical Analysis of nanostructured Cu 2 O using a non-aqueous 3-methoxypropionitrile-based electrolyte
    Electrochemistry Communications, 2017
    Co-Authors: Leyla Shooshtari, Raheleh Mohammadpour
    Abstract:

    Abstract Cu2O is an attractive material in terms of semiconducting properties and is considered a leading candidate in all-oxide photovoltaics. Electrochemical Analysis of Cu2O, including Mott-Schottky (MS) and impedance spectroscopy (IS), provides a wealth of data on charge carriers, Fermi level and interface properties. MS and IS are usually measured in aqueous solutions. However, Cu2O is easily reduced or oxidized to Cu or CuO in aqueous solutions, the layer peels off after the Analysis and there is a small voltage window for the tests. In some cases, an anti-corrosive n-type barrier layer is employed on top of the bare Cu2O electrode to make the measurement possible, which could result in deviation from actual values. Here we introduce a non-aqueous electrolyte based on tetrabutylammonium-tetrafluoroborate in 3-methoxypropionitrile for Electrochemical Analysis of Cu2O. MS Analysis shows reproducible results in terms of dopant density and flat band potential, while the Analysis in aqueous (0.5 M Na2SO4) electrolyte shows inconsistent, irreproducible results. In the case of IS, the transport resistivity of the layers was evaluated using the new electrolyte and shows a linear trend with thickness, as expected. The proposed non-aqueous electrolyte can potentially be used for the Electrochemical Analysis of other sensitive semiconductors.

Genxi Li - One of the best experts on this subject based on the ideXlab platform.

  • Design Nanoprobe Based on Its Binding with Amino Acid Residues on Cell Surface and Its Application to Electrochemical Analysis of Cells.
    Analytical Chemistry, 2018
    Co-Authors: Juan Zhang, Chang Feng, Hong Chen, Genxi Li
    Abstract:

    Nanoprobe usually plays a vital role in the development of new Electrochemical methods for cell Analysis. However, nearly all of the currently used versatile probes are prepared by using lectin. So, a new kind of universal nanoprobe is designed and fabricated in this work for Electrochemical cell Analysis. Specifically, p-sulfonatocalix[4]arene-modified silver nanoparticles (pSC4–AgNPs) are synthesized and explored as a universal nanoprobe. In this probe, pSC4 can recognize and bind to various amino acid residues on the membrane protein, and AgNPs can give a sensitive Electrochemical signal. Therefore, by using the pSC4–AgNPs as a probe, a variety of cells can be well-detected, and the testing results are comparable, showing that the probe has good versatility. At the same time, the detection sensitivity reaches five cells, which is much better than other methods for Electrochemical Analysis of cells, showing its application prospect in trace cell Analysis. In view of the advantages including simplicity o...

  • Electrochemical Analysis of enzyme based on the self assembly of lipid bilayer on an electrode surface mediated by hydrazone chemistry
    Analytical Chemistry, 2017
    Co-Authors: Juan Zhang, Xiaonan Wang, Tingjun Chen, Chang Feng, Genxi Li
    Abstract:

    In this work, a new strategy for Electrochemical Analysis of enzyme has been proposed based on a self-assembled lipid bilayer on an electrode surface mediated by hydrazone chemistry. Taking aldolase as an example, the enzyme can catalyze the formation of products containing carbonyl groups. These groups can react with hydrazine groups of the functional lipid derivative, resulting in the self-assembly of a lipid bilayer on a guanidinium modified electrode surface. The lipid bilayer will then prevent the movement of hydrophilic Electrochemical probes. Consequently, the catalytic reaction of the enzyme may result in the change of the obtained Electrochemical peak current. Experimental results reveal that aldolase activity can be analyzed over a widely linear detection range from 5 mU/L to 100 U/L with a low detection limit of 1 mU/L. Meanwhile, the method can exhibit good precision and reproducibility and it can be applied for real sample Analysis. What is more, because the lipid bilayer is the universal bas...

  • Electrochemical Analysis of Cells
    SpringerBriefs in Molecular Science, 2012
    Co-Authors: Genxi Li, Peng Miao
    Abstract:

    The cell is the basic unit of life, which plays a key role in the development of organisms and participates in almost all physiological processes in vivo. Since the physiological activities of cells are often related to electron transfer and/or electroactive species, electrochemistry is proven to be an effective technique for the Analysis of cells, which can be further used in disease diagnosis and drug screening. Therefore, Electrochemical Analysis of cells has attracted a great many research interests. In recent years, with the development of surface modification technology, molecular recognition and nanotechnology, more and more electrodes with high biocompatibility can be used for cell immobilization, which has greatly promoted the Electrochemical Analysis of cells.

  • Electrochemical Analysis of Proteins
    SpringerBriefs in Molecular Science, 2012
    Co-Authors: Genxi Li, Peng Miao
    Abstract:

    Protein is of great importance to the execution of normal physiological functions of living organisms. Currently, the main techniques for the Analysis of proteins include spectrophotometry, mass spectrometry, electrochemistry, affinity chromatography and enzyme-linked immunosorbent assay (ELISA), etc. Among them, Electrochemical technique receives more and more interests. Especially in recent years, with the continuous improvement of protein-film voltammetry and the recently developed surface modification technology, nanotechnology, signal amplification technology and molecule recognition technology, Electrochemical technique has been gradually overcoming the past drawbacks such as narrow research objects and sole signal format in the Analysis of proteins. In this chapter, we review some typical strategies for the Electrochemical Analysis of protein activity as well as the Electrochemical quantitative Analysis of some proteins.

  • Theoretical Background of Electrochemical Analysis
    SpringerBriefs in Molecular Science, 2012
    Co-Authors: Genxi Li, Peng Miao
    Abstract:

    An electrode is a conductor or semiconductor, which directly contacts the electrolyte solution. In an Electrochemical system, the input and output are both realized through an electrode. The substrate materials of the commonly used electrodes include noble metals (platinum, gold, silver, etc.), mercury, various kinds of carbon materials and semiconductor materials. Since the electron transfer rate between proteins and electrode surfaces is usually prohibitively slow, due to the burying of the electroactive prosthetic groups of most proteins in the electrically insulated peptide backbones and adsorptive denaturation of proteins on electrode surface, chemically modified electrodes (CMEs) are developed to facilitate the Electrochemical Analysis of the biomacromolecules and cells. Meanwhile, different Electrochemical techniques are employed to meet the requirements of different bioassays.

Haleh Ardebili - One of the best experts on this subject based on the ideXlab platform.

  • Thermo-Electrochemical Analysis of lithium ion batteries for space applications using Thermal Desktop
    Journal of Power Sources, 2014
    Co-Authors: William Walker, Haleh Ardebili
    Abstract:

    Abstract Lithium-ion batteries (LIBs) are replacing the Nickel–Hydrogen batteries used on the International Space Station (ISS). Knowing that LIB efficiency and survivability are greatly influenced by temperature, this study focuses on the thermo-Electrochemical Analysis of LIBs in space orbit. Current finite element modeling software allows for advanced simulation of the thermo-Electrochemical processes; however the heat transfer simulation capabilities of said software suites do not allow for the extreme complexities of orbital-space environments like those experienced by the ISS. In this study, we have coupled the existing thermo-Electrochemical models representing heat generation in LIBs during discharge cycles with specialized orbital-thermal software, Thermal Desktop (TD). Our model's parameters were obtained from a previous thermo-Electrochemical model of a 185 Amp-Hour (Ah) LIB with 1–3 C (C) discharge cycles for both forced and natural convection environments at 300 K. Our TD model successfully simulates the temperature vs. depth-of-discharge (DOD) profiles and temperature ranges for all discharge and convection variations with minimal deviation through the programming of FORTRAN logic representing each variable as a function of relationship to DOD. Multiple parametrics were considered in a second and third set of cases whose results display vital data in advancing our understanding of accurate thermal modeling of LIBs.

  • New Techniques for Thermo- Electrochemical Analysis of Lithium-ion Batteries for Space Applications
    2013
    Co-Authors: William Walker, Haleh Ardebili
    Abstract:

    The overall goal of this study was achieved: Replicated the numerical assessment performed by Chen et. al. (2005). Displayed the ability of Thermal Desktop to be coupled with thermo-Electrochemical Analysis techniques. such that the local heat generated on the cells is a function of the model itself using logic blocks and arrays. Differences in the TD temperature vs. depth of discharge profiles and Chen's was most likely due to differences in two primary areas: Contact regions and conductance values. Differences in density and specific heat values. center dot The model results are highly dependent on the accuracy of the material properties with respect to the multiple layers of an individual cell.