Displaying publications 1 - 20 of 470 in total

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  1. Fulltext Targeted DNA complementation on a 1,1'-carbonyldiimidazole-functionalized surface for identifying Mycobacterium tuberculosis
    Xu S, Xue Y, Guo F, Xu M, Gopinath SCB, Mao X
    3 Biotech, 2020 May;10(5):227.
    PMID: 32373419 DOI: 10.1007/s13205-020-02216-2
    Herein, a rapid and sensitive current-volt measurement was developed for identifying the IS6110 DNA sequence to diagnose Mycobacterium tuberculosis (TB). An aminated capture probe was immobilized on a 1,1'-carbonyldiimidazole-functionalized interdigitated electrode (IDE) silica substrate, and the target sequence was detected by complementation. It was found that all tested concentrations displayed a higher response in current changes than the control, and the limit of detection was 10 fM. The sensitivity ranged from 1 to 10 fM. The control sequences with single-, triple-mismatch and noncomplementary sequences showed great discrimination. This rapid and easy DNA detection method helps to identify M. tuberculosis for early-stage diagnosis of TB.
    Matched MeSH terms: Electrodes
  2. Fulltext Quantification of cortisol for the medical diagnosis of multiple pregnancy-related diseases
    Zhang J, Gopinath SCB
    3 Biotech, 2020 Feb;10(2):35.
    PMID: 31988829 DOI: 10.1007/s13205-019-2030-z
    Cortisol is a stress hormone released from the adrenal glands and is responsible for both hyperglycemia and hypertension during pregnancy. These factors make it mandatory to detect the levels of cortisol during pregnancy to identify and treat hypoglycemia and hypertension. In this study, cortisol levels were quantified with an aptamer-conjugated gold nanorod using an electrochemical interdigitated electrode sensor. The surface uniformity was analyzed by high-power microscopy and 3D-nanoprofiler imaging. The detection limit was determined to be 0.01 ng/mL, and a linear regression indicated that the sensitivity range was in the range of 0.01-0.1 ng/mL, based on a 3σ calculation. Moreover, the specificity of the aptamer was determined by a binding analysis against norepinephrine and progesterone, and it was clearly found that the aptamer specifically recognizes only cortisol. Further, the presence of cortisol was detected in the serum in a dose-dependent manner. This method is useful to detect and correlate multiple pregnancy-related diseases by quantifying the levels of cortisol.
    Matched MeSH terms: Electrodes
  3. Interfacial Mechanical Strength Enhancement for High-Performance ZnS Thin-Film Anodes
    Jiang H, Peng H, Guo H, Zeng Y, Li L, Zhang Y, et al.
    ACS Appl Mater Interfaces, 2020 Nov 18;12(46):51344-51356.
    PMID: 33146507 DOI: 10.1021/acsami.0c13139
    Thin-film lithium-ion microbatteries with a high energy density and long lifespan are exceedingly desired for developing self-powered integrated micro-nano devices and systems. However, exploring high-performance thin-film anodes still remains a challenge. Herein, a double-layer-structure diamond-like carbon-ZnS (DLC-ZnS) thin-film anode fabricated by radio frequency magnetron sputtering exhibits high specific capacity and good cycling stability up to 1000 cycles, superior to the pure ZnS thin-film anode. To understand the mechanism, the bimodal amplitude modulated-frequency modulated atomic force microscopy was used to explore the mechanical properties of the thin films, and the DLC layer shows significantly higher Young's modulus than the ZnS thin film. The DLC interface with a high Young's modulus can effectively buffer the mechanical stress originating from the huge volume changes of the ZnS layer during lithiation/delithiation processes; therefore, the DLC interface maintains the higher mechanical integrity of the DLC-ZnS thin film and improves the utilization of ZnS. In addition, the electrochemical kinetics of the DLC-ZnS and ZnS thin films were also investigated by electrochemical methods. Electrochemical impedance spectroscopy tests indicate the obstacle of the DLC interface to Li+ ion diffusion in the initial charge/discharge processes; however, the DLC-ZnS thin film exhibits lower total resistance than the ZnS thin film afterward. In particular, galvanostatic intermittent titration technique tests were performed to find out the differences between the two thin films during the galvanostatical charge/discharge processes. The results demonstrate the obviously enhanced conversion reaction reversibility and decreased alloy reaction polarization of the DLC-ZnS thin film; therefore, it delivers higher reversible capacity.
    Matched MeSH terms: Electrodes
  4. Targeted Surface Doping with Reversible Local Environment Improves Oxygen Stability at the Electrochemical Interfaces of Nickel-Rich Cathode Materials
    Steiner JD, Cheng H, Walsh J, Zhang Y, Zydlewski B, Mu L, et al.
    ACS Appl Mater Interfaces, 2019 Oct 16;11(41):37885-37891.
    PMID: 31589393 DOI: 10.1021/acsami.9b14729
    Elemental doping represents a prominent strategy to improve interfacial chemistry in battery materials. Manipulating the dopant spatial distribution and understanding the dynamic evolution of the dopants at the atomic scale can inform better design of the doping chemistry for batteries. In this work, we create a targeted hierarchical distribution of Ti4+, a popular doping element for oxide cathode materials, in LiNi0.8Mn0.1Co0.1O2 primary particles. We apply multiscale synchrotron/electron spectroscopy and imaging techniques as well as theoretical calculations to investigate the dynamic evolution of the doping chemical environment. The Ti4+ dopant is fully incorporated into the TMO6 octahedral coordination and is targeted to be enriched at the surface. Ti4+ in the TMO6 octahedral coordination increases the TM-O bond length and reduces the covalency between (Ni, Mn, Co) and O. The excellent reversibility of Ti4+ chemical environment gives rise to superior oxygen reversibility at the cathode-electrolyte interphase and in the bulk particles, leading to improved stability in capacity, energy, and voltage. Our work directly probes the chemical environment of doping elements and helps rationalize the doping strategy for high-voltage layered cathodes.
    Matched MeSH terms: Electrodes
  5. A Direct n-Butane Solid Oxide Fuel Cell Using Ba(Zr0.1Ce0.7Y0.1Yb0.1)0.9Ni0.05Ru0.05O3-δ Perovskite as the Reforming Layer
    Wang D, Wong SI, Sunarso J, Xu M, Wang W, Ran R, et al.
    ACS Appl Mater Interfaces, 2021 May 05;13(17):20105-20113.
    PMID: 33886260 DOI: 10.1021/acsami.1c02502
    Hydrocarbon-fueled solid oxide fuel cells (SOFCs) that can operate in the intermediate temperature range of 500-700 °C represent an attractive SOFC device for combined heat and power applications in the industrial market. One of the ways to realize such a device relies upon exploiting an in situ steam reforming process in the anode catalyzed by an anti-carbon coking catalyst. Here, we report a new Ni and Ru bimetal-doped perovskite catalyst, Ba(Zr0.1Ce0.7Y0.1Yb0.1)0.9Ni0.05Ru0.05O3-δ (BZCYYbNRu), with enhanced catalytic hydrogen production activity on n-butane (C4H10), which can resist carbon coking over extended operation durations. Ru in the perovskite lattice inhibits Ni precipitation from perovskite, and the high water adsorption capacity of proton conducting perovskite improves the coking resistance of BZCYYbNRu. When BZCYYbNRu is used as a steam reforming catalyst layer on a Ni-YSZ-supported anode, the single fuel cell not only achieves a higher power density of 1113 mW cm-2 at 700 °C under a 10 mL min-1 C4H10 continuous feed stream at a steam to carbon (H2O/C) ratio of 0.5 but also shows a much better operational stability for 100 h at 600 °C compared with those reported in the literature.
    Matched MeSH terms: Electrodes
  6. Electrochemical Characteristics of a Polymer/Garnet Trilayer Composite Electrolyte for Solid-State Lithium-Metal Batteries
    Walle KZ, Musuvadhi Babulal L, Wu SH, Chien WC, Jose R, Lue SJ, et al.
    ACS Appl Mater Interfaces, 2021 Jan 20;13(2):2507-2520.
    PMID: 33406841 DOI: 10.1021/acsami.0c17422
    Although solid-state Li-metal batteries (LMBs) featuring polymer-based solid electrolytes might one day replace conventional Li-ion batteries, the poor Li-ion conductivity of solid polymer electrolytes at low temperatures has hindered their practical applications. Herein, we describe the first example of using a co-precipitation method in a Taylor flow reactor to produce the metal hydroxides of both the Ga/F dual-doped Li7La3Zr2O12 (Ga/F-LLZO) ceramic electrolyte precursors and the Li2MoO4-modified Ni0.8Co0.1Mn0.1O2 (LMO@T-LNCM 811) cathode materials for LMBs. The Li/Nafion (LiNf)-coated Ga/F-LLZO (LiNf@Ga/F-LLZO) ceramic filler was finely dispersed in the poly(vinylidene fluoride)/polyacrylonitrile/lithium bis(trifluoromethanesulfonimide)/succinonitrile matrix to give a trilayer composite polymer electrolyte (denoted "Tri-CPE") through a simple solution-casting. The bulk ionic conductivity of the Tri-CPE at room temperature was approximately 4.50 × 10-4 S cm-1 and exhibited a high Li+ ion transference number (0.84). It also exhibits a broader electrochemical window of 1-5.04 V versus Li/Li+. A full cell based on a CR2032 coin cell containing the LMO@T-LNCM811-based composite cathode, when cycled under 1 C/1 C at room temperature for 300 cycles, achieved an average Columbic efficiency of 99.4% and a capacity retention of 89.8%. This novel fabrication strategy for Tri-CPE structures has potential applications in the preparation of highly safe high-voltage cathodes for solid-state LMBs.
    Matched MeSH terms: Electrodes
  7. Rapid Surface Modification of Stainless Steel 304L Electrodes for Microbial Electrochemical Sensor Application
    Yeo RYZ, Chin BH, Hil Me MF, Chia JF, Pham HT, Othman AR, et al.
    ACS Biomater Sci Eng, 2023 Nov 13;9(11):6034-6044.
    PMID: 37846081 DOI: 10.1021/acsbiomaterials.3c00453
    Electrogenic microorganisms serve as important biocatalysts for microbial electrochemical sensors (MESes). The electrical signal produced is based on the rate of electron transfer between the microbes and electrodes, which represents the biotoxicity of water. However, existing MESes require complex and sophisticated fabrication methods. Here, several low-cost and rapid surface modification strategies (carbon powder-coated, flame-oxidized, and acid-bleached) have been demonstrated and studied for biosensing purposes. Surface-modified MESe bioanodes were successfully applied to detect multiple model pollutants including sodium acetate, ethanol, thinner, and palm oil mill effluent under three different testing sequences, namely, pollutant incremental, pollutant dumping, and water dilution tests. The carbon powder-coated bioanode showed the most responsive signal profile for all the three tests, which is in line with the average roughness values (Ra) when tested with atomic force microscopy. The carbon powder-coated electrode possessed a Ra value of 0.844, while flame-oxidized, acid-bleached, and control samples recorded 0.323, 0.336, and 0.264, respectively. The higher roughness was caused by the carbon coating and provided adhesive sites for microbial attachment and growth. The accuracy of MESe was also verified by correlating with chemical oxygen demand (COD) results. Similar to the sensitivity test, the carbon powder-coated bioanode obtained the highest R2 value of 0.9754 when correlated with COD results, indicating a high potential of replacing conventional water quality analysis methods. The reported work is of great significance to showcase facile surface modification techniques for MESes, which are cost-effective and sustainable while retaining the biocompatibility toward the microbial community with carbon-based coatings.
    Matched MeSH terms: Electrodes
  8. Fulltext Electrochemical Sodiation/Desodiation into Mn3O4 Nanoparticles
    Mahamad Yusoff NF, Idris NH, Md Din MF, Majid SR, Harun NA, Rahman MM
    ACS Omega, 2020 Nov 17;5(45):29158-29167.
    PMID: 33225147 DOI: 10.1021/acsomega.0c03888
    Mn3O4 is considered to be a promising anode material for sodium-ion batteries (SIBs) because of its low cost, high capacity, and enhanced safety. However, the inferior cyclic stability of the Mn3O4 anode is a major challenge for the development of SIBs. In this study, a one-step solvothermal method was established to produce nanostructured Mn3O4 with an average particle size of 21 nm and a crystal size of 11 nm. The Mn3O4 obtained exhibits a unique architecture, consisting of small clusters composed of numerous tiny nanoparticles. The Mn3O4 material could deliver high capacity (522 mAh g-1 at 100 mA g-1), reasonable cyclic stability (158 mAh g-1 after 200 cycles), and good rate capability (73 mAh g-1 at 1000 mA g-1) even without further carbon coating, which is a common exercise for most anode materials so far. The sodium insertion/extraction was also confirmed by a reversible conversion reaction by adopting an ex situ X-ray diffraction technique. This simple, cost-effective, and environmentally friendly synthesis technique with good electrochemical performance shows that the Mn3O4 nanoparticle anode has the potential for SIB development.
    Matched MeSH terms: Electrodes
  9. Co-Electrolysis-Assisted Decomposition of Hydroxylammonium Nitrate-Fuel Mixtures Using Stainless Steel-Platinum Electrodes
    Chai WS, Sun D, Cheah KH, Li G, Meng H
    ACS Omega, 2020 Aug 11;5(31):19525-19532.
    PMID: 32803046 DOI: 10.1021/acsomega.0c01804
    Hydroxylammonium nitrate (HAN) is a promising green propellant because of its low toxicity, high volumetric specific impulse, and reduced development cost. Electrolytic decomposition of HAN is an efficient approach to prepare it for further ignition and combustion. This paper describes the investigation of a co-electrolysis effect on electrolytic decomposition of HAN-fuel mixtures using stainless steel-platinum (SS-Pt) electrodes. For the first time, different materials were utilized as electrodes to alter the cathodic reaction, which eliminated the inhibition effect and achieved a repeatable and consistent electrolytic decomposition of HAN solution. Urea and methanol were added as fuel components in the HAN-fuel mixtures. When the mass ratio of added urea ≥20%, the electrolytic decomposition of a HAN-urea ternary mixture achieved 67% increment in maximum gas temperature (Tgmax) and 185% increment in overall temperature increasing rate over the benchmark case of HAN solution. The co-electrolysis of urea released additional electrons into the mixtures and enhanced the overall electrolytic decomposition of HAN. In contrast, the addition of methanol did not improve the Tgmax but only increased the overall temperature increasing rate. This work has important implications in the development of an efficient and reliable electrolytic decomposition system of HAN and its mixtures for propulsion applications.
    Matched MeSH terms: Electrodes
  10. Fulltext Ultrasonic Assisted Synthesis of Size-Controlled Cu-Metal-Organic Framework Decorated Graphene Oxide Composite: Sustainable Electrocatalyst for the Trace-Level Determination of Nitrite in Environmental Water Samples
    Arul P, Gowthaman NSK, John SA, Lim HN
    ACS Omega, 2020 Jun 23;5(24):14242-14253.
    PMID: 32596560 DOI: 10.1021/acsomega.9b03829
    Excess levels of nitrite ion in drinking water interact with amine functionalized compounds to form carcinogenic nitrosamines, which cause stomach cancer. Thus, it is indispensable to develop a simple protocol to detect nitrite. In this paper, a Cu-metal-organic framework (Cu-MOF) with graphene oxide (GO) composite was synthesized by ultrasonication followed by solvothermal method and then fabricated on a glassy carbon (GC) electrode for the sensitive and selective determination of nitrite contamination. The SEM image of the synthesized Cu-MOF showed colloidosome-like structure with an average size of 8 μm. Interestingly, the Cu-MOF-GO composite synthesized by ultrasonic irradiation followed by solvothermal process produce controlled size of 3 μm colloidosome-like structure. This was attributed to the formation of an exfoliated sheet-like structure of GO by ultrasonication in addition to the obvious influence of GO providing the oxygen functional groups as a nucleation node for size-controlled growth. On the other hand, the composite prepared without ultrasonication exhibited 6.6 μm size agglomerated colloidosome-like structures, indicating the crucial role of ultrasonication for the formation of size-controlled composites. XPS results confirmed the presence of Cu(II) in the as-synthesized Cu-MOF-GO based on the binding energies at 935.5 eV for Cu 2p3/2 and 955.4 eV for Cu 2p1/2. The electrochemical impedance studies in [Fe(CN)6]3-/4- redox couple at the composite fabricated electrode exhibited more facile electron transfer than that with Cu-MOF and GO modified electrodes, which helped to utilize Cu-MOF-GO for trace level determination of nitrite in environmental effluent samples. The Cu-MOF-GO fabricated electrode offered a superior sensitive platform for nitrite determination than the Cu-MOF and GO modified electrodes demonstrating oxidation at less positive potential with enhanced oxidation current. The present sensor detects nitrite in the concentration range of 1 × 10-8 to 1 × 10-4 M with the lowest limit of detection (LOD) of 1.47 nM (S/N = 3). Finally, the present Cu-MOF-GO electrode was successfully exploited for nitrite ion determination in lake and dye contaminated water samples.
    Matched MeSH terms: Electrodes
  11. Fulltext A simple, portable, electrochemical biosensor to screen shellfish for Vibrio parahaemolyticus
    Nordin N, Yusof NA, Abdullah J, Radu S, Hushiarian R
    AMB Express, 2017 Dec;7(1):41.
    PMID: 28205102 DOI: 10.1186/s13568-017-0339-8
    An earlier electrochemical mechanism of DNA detection was adapted and specified for the detection of Vibrio parahaemolyticus in real samples. The reader, based on a screen printed carbon electrode, was modified with polylactide-stabilized gold nanoparticles and methylene blue was employed as the redox indicator. Detection was assessed using a microprocessor to measure current response under controlled potential. The fabricated sensor was able to specifically distinguish complementary, non-complementary and mismatched oligonucleotides. DNA was measured in the range of 2.0 × 10(-8)-2.0 × 10(-13) M with a detection limit of 2.16 pM. The relative standard deviation for 6 replications of differential pulse voltammetry (DPV) measurement of 0.2 µM complementary DNA was 4.33%. Additionally, cross-reactivity studies against various other food-borne pathogens showed a reliably sensitive detection of the target pathogen. Successful identification of Vibrio parahaemolyticus (spiked and unspiked) in fresh cockles, combined with its simplicity and portability demonstrate the potential of the device as a practical screening tool.
    Matched MeSH terms: Electrodes
  12. Fulltext Physical characterization of the screen-printed carbon electrode surface using scanning electron micrograph
    Issa, R., Hamdan, N.A., Raj, A.S.S., Noh, M.F.M.
    ASM Science Journal, 2011;5(1):36-42.
    MyJurnal
    Researchers have developed and modified DNA biosensor techniques to provide a fast, simple and sensitive method for detection of human diseases, bacterial food contamination, forensic and environmental research. This study describes the physical characterization of screen-printed carbon electrodes using the scanning electron microscope.
    Matched MeSH terms: Electrodes
  13. Fulltext Preliminary characterization study based on cyclic voltammetry and reliability of a fabricated Au/Ti microfluidic three-electrode sensor
    Hamzah, I.H., Sidek, O., Abd Manaf, A.
    ASM Science Journal, 2010;4(2):142-148.
    MyJurnal
    A preliminary study was carried out to fabricate a three electrode system based on electrochemical sensoring. The cyclic voltammetry (CV) technique was chosen to select the type of metal suitable for evaporation and to compare the results produced from the fabricated gold electrode with the conventional macro-electrode system. The methodology and apparatus used involved low cost apparatus and methodology such as soft lithography, wet-etching, thermal evaporation, direct current sputtering, polymethylmethacrylate moulding and polydimethylsiloxane coating. The experiment was conducted at a fixed scan rate of 100 mV/s by using 0.01 M K3Fe(CN)6 in 0.1M KCl and well known method using Randles-Sevcik equation, peak current ratio and voltage separation was used to analyze the characterization on the fabricated sensors. Electrodes of 6.5 mm2 and 0.26 mm2 were fabricated to prove the adsorption effect of the reactant and the influence of the electrode area on the value of the peak current. CV analysis proved that the fabricated sensor was reliable for a range of 24 h at 25ºC room temperature.
    Matched MeSH terms: Electrodes
  14. Fulltext 2-hydroxyethyl cellulose as natural binder in electrodes for solid-state proton battery: construction and preliminary results
    Ramlli, M.A., Isa, M.I.N., Yu, K.X., Siew, Y.W.
    ASM Science Journal, 2018;11(101):47-55.
    MyJurnal
    Affordable and greener materials were extensively studied in electrode fabrication for Liion
    based batteries but less interest was shown to proton battery. Hence, in this work,
    a methodology on preparing a natural based binder for proton battery was reported. 2-
    Hydroxyethyl Cellulose (2HEC) was chosen to replace PVDF commercial binder in electrode
    for ZnSO4|MnO2 proton battery configuration. SEM image shows good surface formation
    for both anode and cathode with good porous structure. OCV result shows that the cell
    improved the stable voltage of reference cell of 0.7 V to 0.9 V after 24 hours. The first
    discharge of the cell took 6 hours and 49 minutes at 0.005mA and shows good potential for
    rechargebility test.
    Matched MeSH terms: Electrodes
  15. Does the location of electrode on tympanic membrane matter when recording electrocochleography?
    Zakaria MN, Nik Othman NA, Musa Z
    Acta Otolaryngol, 2021 Nov;141(11):984-988.
    PMID: 34669557 DOI: 10.1080/00016489.2021.1990996
    BACKGROUND: The non-invasive tympanic electrocochleography (TM-ECochG) is useful for clinical diagnoses. Nevertheless, the influence of the electrode location on tympanic membrane (TM) on ECochG results needs to be studied.

    OBJECTIVE: The aim of the present study was to compare the TM-ECochG results obtained when the electrode was placed on the superior region versus the inferior region of TM.

    MATERIALS AND METHODS: Forty healthy adults (aged 29 to 50 years) participated in this comparative study. The TM-ECochG testing was conducted with the electrode placed on the superior and inferior regions of TM.

    RESULTS: SP and AP amplitudes were statistically higher for the inferior region of TM (p < .05). In contrast, SP/AP ratios were comparable between the two regions of TM (p = .417).

    CONCLUSIONS AND SIGNIFICANCE: In TM-ECochG recording, when the electrode was placed on the inferior region of TM, SP and AP amplitudes were greater than when the electrode was placed on the superior region of TM. On the other hand, SP/AP amplitude ratio was not affected by the location of electrode on TM. The findings from the present study could be useful to guide clinicians in optimizing TM-ECochG recording when testing their respective patients.

    Matched MeSH terms: Electrodes*
  16. Recent Progress on Advanced Materials for Solid-Oxide Fuel Cells Operating Below 500 °C
    Zhang Y, Knibbe R, Sunarso J, Zhong Y, Zhou W, Shao Z, et al.
    Adv Mater, 2017 Dec;29(48).
    PMID: 28628239 DOI: 10.1002/adma.201700132
    Solid-oxide fuel cells (SOFCs) are electricity generators that can convert the chemical energy in various fuels directly to the electric power with high efficiency. Recent advances in materials and related key components for SOFCs operating at ≈500 °C are summarized here, with a focus on the materials, structures, and techniques development for low-temperature SOFCs, including the analysis of most of the critical parameters affecting the electrochemical performance of the electrolyte, anode, and cathode. New strategies, such as thin-film deposition, exsolution of nanoparticles from perovskites, microwave plasma heating, and finger-like channeled electrodes, are discussed. These recent developments highlight the need for electrodes with higher activity and electrolytes with greater conductivity to generate a high electrochemical performance at lower temperatures.
    Matched MeSH terms: Electrodes
  17. Effects of Different Electrode Configurations on the Narrow Band Level-Specific CE-Chirp and Tone-Burst Auditory Brainstem Response at Multiple Intensity Levels and Frequencies in Subjects With Normal Hearing
    Dzulkarnain AAA, Abdullah SA, Ruzai MAM, Ibrahim SHMN, Anuar NFA, Rahim 'EA
    Am J Audiol, 2018 Sep 12;27(3):294-305.
    PMID: 30054628 DOI: 10.1044/2018_AJA-17-0087
    Purpose: The purpose of this study was to investigate the influence of 2 different electrode montages (ipsilateral and vertical) on the auditory brainstem response (ABR) findings elicited from narrow band (NB) level-specific (LS) CE-Chirp and tone-burst in subjects with normal hearing at several intensity levels and frequency combinations.

    Method: Quasi-experimental and repeated-measures study designs were used in this study. Twenty-six adults with normal hearing (17 females, 9 males) participated. ABRs were acquired from the study participants at 3 intensity levels (80, 60, and 40 dB nHL), 3 frequencies (500, 1000, and 2000 Hz), 2 electrode montages (ipsilateral and vertical), and 2 stimuli (NB LS CE-Chirp and tone-burst) using 2 stopping criteria (fixed averages at 4,000 sweeps and F test at multiple points = 3.1).

    Results: Wave V amplitudes were only 19%-26% larger for the vertical recordings than the ipsilateral recordings in both the ABRs obtained from the NB LS CE-Chirp and tone-burst stimuli. The mean differences in the F test at multiple points values and the residual noise levels between the ABRs obtained from the vertical and ipsilateral montages were statistically not significant. In addition, the ABR elicited from the NB LS CE-Chirp was significantly larger (up to 69%) than those from the tone-burst, except at the lower intensity level.

    Conclusion: Both the ipsilateral and vertical montages can be used to record ABR to the NB LS CE-Chirp because of the small enhancement in the wave V amplitude provided by the vertical montage.

    Matched MeSH terms: Electrodes*
  18. Amperometric microbiosensor as an alternative tool for investigation of D-serine in brain
    Mohd Zain Z, Ab Ghani S, O'Neill RD
    Amino Acids, 2012 Nov;43(5):1887-94.
    PMID: 22865247 DOI: 10.1007/s00726-012-1365-0
    This paper discusses the application of a reagentless, selective microbiosensor as a useful alternative tool for monitoring D-serine in neural samples. The main components of the 125-μm-diameter disk biosensor were D-amino acid oxidase for D-serine sensitivity (linear region slope, 61 ± 7 μA cm(-2) mM(-1); limit of detection, 20 nM), and poly-phenylenediamine for rejection of electroactive interference. The response time of the biosensor was of the order of 1 s, ideal for 'real-time' monitoring, and detection of systemically administered D-serine in brain extracellular fluid is demonstrated. Exploitation of this probe might resolve queries involving regulation of D-serine in excitotoxicity, and modulation of N-methyl-D-aspartate receptor function by D-serine and glycine in the central nervous system.
    Matched MeSH terms: Electrodes, Implanted
  19. Facile hydrothermal growth graphene/ZnO nanocomposite for development of enhanced biosensor
    Low SS, Tan MT, Loh HS, Khiew PS, Chiu WS
    Anal Chim Acta, 2016 Jan 15;903:131-41.
    PMID: 26709306 DOI: 10.1016/j.aca.2015.11.006
    Graphene/zinc oxide nanocomposite was synthesised via a facile, green and efficient approach consisted of novel liquid phase exfoliation and solvothermal growth for sensing application. Highly pristine graphene was synthesised through mild sonication treatment of graphite in a mixture of ethanol and water at an optimum ratio. The X-ray diffractometry (XRD) affirmed the hydrothermal growth of pure zinc oxide nanoparticles from zinc nitrate hexahydrate precursor. The as-prepared graphene/zinc oxide (G/ZnO) nanocomposite was characterised comprehensively to evaluate its morphology, crystallinity, composition and purity. All results clearly indicate that zinc oxide particles were homogenously distributed on graphene sheets, without any severe aggregation. The electrochemical performance of graphene/zinc oxide nanocomposite-modified screen-printed carbon electrode (SPCE) was evaluated using cyclic voltammetry (CV) and amperometry analysis. The resulting electrode exhibited excellent electrocatalytic activity towards the reduction of hydrogen peroxide (H2O2) in a linear range of 1-15 mM with a correlation coefficient of 0.9977. The sensitivity of the graphene/zinc oxide nanocomposite-modified hydrogen peroxide sensor was 3.2580 μAmM(-1) with a limit of detection of 7.4357 μM. An electrochemical DNA sensor platform was then fabricated for the detection of Avian Influenza H5 gene based on graphene/zinc oxide nanocomposite. The results obtained from amperometry study indicate that the graphene/zinc oxide nanocomposite-enhanced electrochemical DNA biosensor is significantly more sensitive (P 
    Matched MeSH terms: Electrodes
  20. Sensitive voltammetric determination of paracetamol by poly (4-vinylpyridine)/multiwalled carbon nanotubes modified glassy carbon electrode
    Ghadimi H, Tehrani RM, Ali AS, Mohamed N, Ab Ghani S
    Anal Chim Acta, 2013 Feb 26;765:70-6.
    PMID: 23410628 DOI: 10.1016/j.aca.2012.12.039
    A novel glassy carbon electrode (GCE) modified with a composite film of poly (4-vinylpyridine) (P4VP) and multiwalled carbon nanotubes (P4VP/MWCNT GCE) was used for the voltammetric determination of paracetamol (PCT). This novel electrode displayed a combined effect of P4VP and MWCNT on the electro-oxidation of PCT in a solution of phosphate buffer at pH 7. Hence, conducting properties of P4VP along with the remarkable physical properties of MWCNTs might have combined effects in enhancing the kinetics of PCT oxidation. The P4VP/MWCNT GCE has also demonstrated excellent electrochemical activity toward PCT oxidation compared to that with bare GCE and MWCNT GCE. The anodic peak currents of PCT on the P4VP/MWCNT GCE were about 300 fold higher than that of the non-modified electrodes. By applying differential pulse voltammetry technique under optimized experimental conditions, a good linear ratio of oxidation peak currents and concentrations of PCT over the range of 0.02-450 μM with a limit of detection of 1.69 nM were achieved. This novel electrode was stable for more than 60 days and reproducible responses were obtained at 99% of the initial current of PCT without any influence of physiologically common interferences such as ascorbic acid and uric acid. The application of this electrode to determine PCT in tablets and urine samples was proposed.
    Matched MeSH terms: Electrodes
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