共查询到20条相似文献,搜索用时 46 毫秒
1.
M. Yousef Elahi H. Heli S. Z. Bathaie M. F. Mousavi 《Journal of Solid State Electrochemistry》2007,11(2):273-282
The electrocatalytic oxidation of glucose was investigated on a nickel-basedchemically modified electrode (Ni(II)-curcumin) prepared by electropolymerization of Ni-curcumin complex (curcumin=1,7-bis[4-hydroxy-3-methoxyphenyl]-1,6-heptadiene-3,5-dione) in alkaline solution. Reaction kinetic and mechanism were investigated by using cyclic voltammetry (CV) and chronoamperometry (CA) techniques and steady-state polarization measurements. Cyclic voltammetry studies indicated that in the presence of glucose the anodic peak current of surface redox mediator was increased, followed by decrease in the corresponding cathodic current. This indicates that glucose was oxidized at the surface of this modified electrode. The results were explained based on the concept of electrocatalytic reactions that occur in this chemically modified electrode. The diffusion coefficient of glucose and the rate constant of the catalytic oxidation of glucose were found to be 6.7×10−6 cm2 s−1 and 6.5×103 M−1 s−1, respectively. It has shown that by using the Ni-curcumin modified electrode, glucose can be determined with good response and low detection limit. 相似文献
2.
Juliana Canto Duarte Rita de Cássia Silva Luz Flavio Santos Damos Adriano Bof de Oliveira Lauro Tatsuo Kubota 《Journal of Solid State Electrochemistry》2007,11(5):631-638
The electrocatalytical oxidation of hydrazine at low potential using tetracyanoquinodimethanide adsorbed on silica modified
with titanium oxide was investigated by cyclic voltammetry and amperometry. The modified electrode was prepared modifying
a carbon paste electrode employing lithium tetracyanoquinodimethanide adsorbed onto silica gel modified with titanium oxide.
This electrode showed an excellent catalytic activity and stability for hydrazine oxidation. With this modified electrode,
the oxidation potential of hydrazine was shifted toward less positive value, presenting a peak current much higher than those
observed on a bare GC electrode. The linear response range, sensitivity and detection limit were, respectively, 2 up to 100 μmol
l−1, 0.36 μA l μmol−1, and 0.60 μmol l−1. The repeatability of the modified electrode evaluated in term of relative standard deviation was 4.2% for 10 measurements
of 100 μmol l−1 hydrazine solution. The number of electrons involved in hydrazine oxidation (4), the heterogenous electron transfer rate
constant (1.08 × 103 mol−1 l s−1), and diffusion coefficient (5.9 × 10−6 cm2 s−1) were evaluated with a rotating disk electrode. 相似文献
3.
Liang Wang Jun Yue Bai Peng Fei Huang Hong Jing Wang Xiao Wei Wu Yu Qing Zhao 《Mikrochimica acta》2007,158(1-2):73-78
The electrochemical behaviors of uric acid (UA) at the penicillamine (Pen) self-assembled monolayers modified gold electrode
(Pen/Au) have been studied. The Pen/Au electrode is demonstrated to promote the electrochemical response of UA by cyclic voltammetry
(CV). The diffusion coefficient D of UA is 6.97 × 10−6 cm2 s−1. In differential pulse voltammetric (DPV) measurements, the Pen/Au electrode can separate the UA and ascorbic acid (AA) oxidation
potentials by about 120 mV and can be used for the selective determination of UA in the presence of AA. The detection limit
was 1 × 10−6 mol L−1. The modified electrode shows excellent sensitivity, good selectivity and antifouling properties. 相似文献
4.
Salimi Abollah Noorbakhsh Abdollah Semnani Abolfazl 《Journal of Solid State Electrochemistry》2011,15(9):2041-2052
A simple method was used to fabricate flavin adenine dinucleotide (FAD)/NiOx nanocomposite on the surface of glassy carbon
(GC) electrode. Cyclic voltammetry technique was applied for deposition nickel oxide nanostructures onto GC surface. Owing
to its high biocompatibility and large surface area of nickel oxide nanomaterials with immersing the GC/NiOx-modified electrode
into FAD solution for a short period of time, 10–140 s, a stable thin layer of the FAD molecules immobilized onto electrode
surface. The FAD/NiOx films exhibited a pair of well-defined, stable, and nearly reversible CV peaks at wide pH range (2–10).
The formal potential of adsorbed FAD onto nickel oxide nanoparticles film, E
o′ vs. Ag/AgCl reference electrode is −0.44 V in pH 7 buffer solutions was similar to dissolved FAD and changed linearly with
a slope of 58.6 mV/pH in the pH range 2–10. The surface coverage and heterogeneous electron transfer rate constant (k
s
) of FAD immobilized on NiOx film glassy carbon electrode are 4.66 × 10−11 mol cm−2 and 63 ± 0.1 s−1, indicating the high loading ability of the nickel oxide nanoparticles and great facilitation of the electron transfer between
FAD and nickel oxide nanoparticles. FAD/NiOx nanocomposite-modified GC electrode shows excellent electrocatalytic activity
toward S2O82− reduction at reduced overpotential. Furthermore, rotated modified electrode illustrates good analytical performance for amperometric
detection of S2O82−. Under optimized condition, the concentration calibration range, detection limit, and sensitivity were 3 μM–1.5 mM, 0.38 μM
and 16.6 nA/μM, respectively. 相似文献
5.
A novel type of glassy carbon electrode modified with magnetic carbon-coated nickel nanoparticles (C-Ni/GCE) was fabricated
and the electrochemical properties of brucine were studied using it. The carbon-coated nickel nanoparticles showed excellent
electrocatalytic activity for the redox of brucine and an enhanced electron transfer rate. The electrochemical behavior of
brucine on the C-Ni/GCE was explored by cyclic voltammetry (CV), and a redox mechanism for brucine was proposed. A series
of electrochemical parameters were calculated for brucine by CV and controlled-potential electrolysis. The C-Ni/GCE showed
good sensitivity, selectivity and stability, and was applied to determine the concentration of brucine. The differential pulse
voltammetry (DPV) response of the C-Ni/GCE showed that the catalytic current was linear with the concentration of brucine
in the range of 4.7 × 10−8 to 2.4 × 10−4 mol l−1, with a correlation coefficient of 0.998. The detection limit was 1.4 × 10−8 mol l−1. 相似文献
6.
A self-assembled electrode with a meso-2,3-dimercaptosuccinic acid (DMSA) monolayer has been characterized by electrochemical
quartz crystal microbalance and complex impedance analysis, surface enhanced Raman spectroscopy and cyclic voltammetry. The
self-assembled electrode was used for the simultaneous electrochemical detection of epinephrine (EP) and uric acid (UA) in
phosphate buffer of pH 7.7. The simultaneous oxidation of EP and UA was performed by cyclic voltammetry (CV) and differential
pulse voltammetry (DPV), and the signals for each method were well separated with a potential difference of over 330 mV and
without interference by each other. The detection limit of EP is 5.4 × 10−8 mol L−1 by CV and 5.3 × 10−8 mol L−1 by DPV and that of UA is 8.4 × 10−8 mol L−1 by CV and 4.2 × 10−8 mol L−1 by DPV. The DMSA self-assembled electrode can be applied to the simultaneous determination of EP and UA. 相似文献
7.
Reza Ojani Jahan-Bakhsh Raoof Shahla Fathi Sharife Alami-Valikchali 《Journal of Solid State Electrochemistry》2011,15(9):1935-1941
Nickel ions were incorporated in NaY zeolite according to cation exchange mechanism. Then NiY zeolite was used as modifier
for preparation of modified carbon paste electrode. The electrochemical behavior of NiY-modified carbon paste electrode (NiY/CPE)
was studied in alkaline solution using cyclic voltammetry method. Ability of different electrodes containing NiY/CPE, Ni-NiY/CPE,
Ni-NaY/CPE, and Ni/CPE for electrocatalytic oxidation of methanol was compared (three last electrodes prepared by open circuit
accumulation of Ni(II) ions on the surface of NiY/CPE, NaY/CPE, and bare CPE, respectively). Results show that Ni-NiY/CPE
is best catalyst for the electrochemical oxidation of methanol in alkaline solution and both process of earlier Ni ion incorporation
through cation exchange in NaY zeolite and open circuit accumulation of Ni ion on the surface of electrode are essential to
have good catalyst. Effect of graphite–zeolite ratio on electrocatalytic current was studied and 3:1 ratio of graphite–zeolite
was selected as optimum ratio for preparing electrode. Ni-NiY/CPE has very good stability toward the methanol oxidation in
concentration range of 0.005 to 0.5 M. Finally, using chronoamperometric method, the catalytic rate constant (k) for methanol was found to be 1.56 × 104 cm3 mol−1 s−1. 相似文献
8.
Alireza Feizbakhsh Ali Aghassi Ali Ehsani Malihe A. Jamaat Ali Naeemy Iman Danaee 《中国化学会会志》2012,59(9):1086-1093
In this study we investigated the electrocatalytic oxidation of anti‐inflammatory drug (paracetamol) on Nickel and Nickel–copper alloy modified glassy carbon electrodes (GC/Ni and GC/NiCu) in alkaline solution. These electrodes prepared by galvanostatic method and different electrochemical techniques such as cyclic voltammetry and chronoamperometry were used to track the oxidation process and its kinetics. From Voltammetric studies we concluded that in the presence of drugs the anodic peak current of low valences Nickel species increased, followed by a decrease in the corresponding cathodic current peak. This indicates that drugs were oxidized on the redox mediator which was immobilized on the electrode surface via an electrocatalytic mechanism. Using Laviron's equation, the values of α and ks for the immobilized redox species were determined. The anodic peak currents show linear dependency with the square root of scan rate. This behavior is the characteristic of a diffusion controlled process. Under the CA regime the reaction followed a Cottrellian behavior and the diffusion coefficient of paracetamol was found in agreement with the values obtained from CV measurements. 相似文献
9.
Xiaolan Hou Guijun Shen Liang Meng Ling Zhu Ming Guo 《Russian Journal of Electrochemistry》2011,47(11):1262-1267
Multi-walled carbon nanotubes (MWNTs) modified glassy carbon electrode (GCE) was simply and conveniently fabricated. The electrochemical
properties of paracetamol (PCT) at the prepared modified electrode were investigated by cyclic voltammetry (CV). Based on
this, an ultrasensitive and rapid electrochemical method was developed for the determination of PCT. The result indicated
that the oxidation of PCT was greatly improved at the MWNTs-modified GC (MWNTs/GC) electrode as compared with the bare GC
electrode, with relatively high sensitivity, stability and life time. Good linear relationship between the oxidation peak
current and the PCT concentration in the range of 1 × 10−7 to 1 × 10−3 M (r = 0.996) was obtained in phosphate buffer solution (PBS) with pH 6.5, the detection limit was 2 × 10−8 M (S/N = 3) by use of modified electrode. The proposed method was successfully applied to the PCT determination in tablets. 相似文献
10.
Self-assembled monolayers (SAMS) of chemisorbed thioglycollate on a gold electrode surface have been used as a base interface
for the electrostatic adsorption of ferrocenium ion. Electrochemical impedance spectra (EIS) and cyclic voltammetry (CV) were
used to evaluate the electrochemical properties of the supramolecular film. The bare gold electrode failed to distinguish
the oxidation peaks of ascorbic acid (AA) and uric acid (UA) in phosphate buffer solution (PBS, pH 7.0), while the ferricinium–thioglycollate
modified electrode could separate them efficiently. In differiential pulse voltammetric measurements, the prepared gold electrode
could separate AA and UA signals, allowing the simultaneous determination of AA and UA. Under optimal conditions and within
the linear range of 1.0 × 10−6 to 5.0 × 10−4 M, the detection limits of AA and UA achieved were 2.0 × 10−7 and 1.0 × 10−7 M, respectively. The applicability of the prepared electrode was demonstrated by measuring AA and UA in human urine without
any pretreatment.
Figure Fabrication process for the modified electrode 相似文献
11.
CeO2 nanoparticles approximately 12 nm in size were synthesized and subsequently characterized by XRD, TEM and UV-vis spectroscopy.
Then, a gold electrode modified with CeO2 nanoparticles was constructed and characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV).
The modified electrode demonstrated strong catalytic effects with high stability towards electrochemical oxidation of rutin.
The anodic peak currents (measured by differential pulse voltammetry) increased linearly with the concentration of rutin in
the range of 5.0 × 10−7–5.0 × 10−4 mol · L−1. The detection limit (S/N = 3) was 2.0 × 10−7 mol · L−1. The relative standard deviation (RSD) of 8 successive scans was 3.7% for 5.0 × 10−6 mol · L−1 rutin. The method showed excellent sensitivity and stability, and the determination of rutin in tablets was satisfactory. 相似文献
12.
Covalent modification of a glassy carbon electrode with penicillamine for simultaneous determination of hydroquinone and catechol 总被引:1,自引:0,他引:1
Liang Wang Peng Fei Huang Jun Yue Bai Hong Jing Wang Li Ying Zhang Yu Qing Zhao 《Mikrochimica acta》2007,158(1-2):151-157
A simple and highly selective electrochemical method has been developed for the simultaneous determination of hydroquinone
(HQ) and catechol (CC) at a glassy carbon electrode covalently modified with penicillamine (Pen). The electrode is used for
the simultaneous electrochemical determination of HQ and CC and shows an excellent electrocatalytical effect on the oxidation
of HQ and CC upon cyclic voltammetry in acetate buffer solution of pH 5.0. In differential pulse voltammetric measurements,
the modified electrode was able to separate the oxidation peak potentials of HQ and CC present in binary mixtures by about
103 mV although the bare electrode gave a single broad response. The determination limit of HQ in the presence of 0.1 mmol L−1 CC was 1.0 × 10−6 mol L−1, and the determination limit of CC in the presence of 0.1 mmol L−1 HQ was 6.0 × 10−7 mol L−1. The method was applied to the simultaneous determination of HQ and CC in a water sample. It is simple and highly selective. 相似文献
13.
Nickel‐modified glassy carbon electrode (GC/Ni) prepared by galvanostatic deposition was used for the electrocatalytic oxidation of glucose in alkaline solutions where different electrochemical methods were employed. In cyclic voltammetry studies, in the presence of glucose an increase in the peak current of the oxidation of nickel hydroxide is followed by a decrease in the corresponding cathodic current. This suggests that the oxidation of glucose is being catalyzed through mediated electron transfer across the nickel hydroxide layer comprising nickel ions of various valence states. Under the chronoamperometric regime, the reaction followed a Cottrellian behavior and the diffusion coefficient of glucose was found to be 8 × 10?6 cm2 s?1. A mechanism based on the electrochemical generation of Ni3+‐active sites and their subsequent consumptions by glucose has been discussed, and kinetic parameters have been derived. The heterogeneous rate constants for the oxidation of glucose at the surface of modified electrodes were determined by rotating disk electrode using the Koutecky–Levich plots, which are in agreement with the data obtained by chronoamperometry. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 712–721, 2012 相似文献
14.
M. Houshmand A. Jabbari H. Heli M. Hajjizadeh A. A. Moosavi-Movahedi 《Journal of Solid State Electrochemistry》2008,12(9):1117-1128
The electrocatalytic oxidation of aspirin and acetaminophen on nanoparticles of cobalt hydroxide electrodeposited on the surface
of a glassy carbon electrode in alkaline solution was investigated. The process of oxidation and the kinetics have been investigated
using cyclic voltammetry, chronoamperometry, and steady-state polarization measurements. Voltammetric studies have indicated
that in the presence of drugs, the anodic peak current of low valence cobalt species increases, followed by a decrease in
the corresponding cathodic current. This indicates that drugs are oxidized on the redox mediator which is immobilized on the
electrode surface via an electrocatalytic mechanism. With the use of Laviron’s equation, the values of anodic and cathodic
electron-transfer coefficients and charge-transfer rate constant for the immobilized redox species were determined as α
s,a = 0.72, α
s,c = 0.30, and k
s = 0.22 s−1. The rate constant, the electron transfer coefficient, and the diffusion coefficient involved in the electrocatalytic oxidation
of drugs were reported. It was shown that by using the modified electrode, aspirin and acetaminophen can be determined by
amperometric technique with detection limits of 1.88 × 10−6 and 1.83 × 10−6 M, respectively. By analyzing the content of acetaminophen and aspirin in bulk forms using chronoamperometric and amperometric
techniques, the analytical utility of the modified electrode was achieved. The method was also proven to be valid for analyzing
these drugs in urine samples. 相似文献
15.
A study of the electrocatalytic oxidation of aspirin on a nickel hydroxide-modified nickel electrode
The electrocatalytic oxidation of aspirin has been investigated on a nickel oxide-modified nickel electrode in alkaline solution.
The process of oxidation and its kinetics have been investigated by using cyclic voltammetry, chronoamperometry, and electrochemical
impedance spectroscopy techniques and also steady-state polarization measurements. Voltammetric studies have indicated that
in the presence of aspirin, the anodic peak current of low-valence nickel species increases, followed by a decrease in the
corresponding cathodic current. This indicates that aspirin was oxidized on the redox mediator immobilized on the electrode
surface via an electrocatalytic mechanism. The rate constant of the catalytic oxidation of aspirin and the electron transfer
coefficient have been found to be 1.15×105 cm3 mol−1s−1 and 0.49, respectively. Impedance measurements show that aspirin is diffused into the bulk of the modifier film, and the
oxidation process of aspirin occurs in the bulk of nickel oxide film. It has been shown that by using this modified electrode,
aspirin can be determined with a detection limit of 4.8×10−5 and successfully applied for determination of aspirin in tablet. 相似文献
16.
A new modified electrode was prepared by electrodeposition of caffeic acid (CFA) at the surface of an activated glassy carbon
electrode. Cyclic voltammetry was used to investigate the redox properties of this electrode at various solution pH values
and at various scan rates. The pH dependence of the electrode response was found to be 58.5 mV/pH, which is very close to
the expected Nernstian value. The electrode was also employed to study electrocatalytic oxidation of reduced nicotinamide
adenine dinucleotide (NADH), using cyclic voltammetry, chronoamperometry and rotating disk voltammetry as diagnostic techniques.
It was found that the modified electrode exhibits potent and persistent electrocatalytic properties toward NADH oxidation
in phosphate buffer solution (pH 7.0) with a diminution of the overpotential of about 450 mV compared to the process at an
unmodified electrode. The electrocatalytic current increases linearly with NADH concentration in the range tested from 0.05
to 1.0 mM. The apparent charge transfer rate constant and transfer coefficient for electron transfer between the electrode
surface and immobilized CFA were calculated as 11.2 s−1 and 0.43, respectively. The heterogeneous rate constant for oxidation of NADH at the CFA-modified electrode surface was also
determined and found to be about 3 × 103 M−1 s−1. Finally, the diffusion coefficient of NADH was calculated as 3.24 × 10−6 cm2 s−1 for the experimental conditions, using chronoamperometric results.
Received: 6 January 1999 / Accepted: 11 May 1999 相似文献
17.
A voltammetric sensor for the determination of parathion has been developed based on the use of a poly(carmine) film electrode.
The reduction of parathion at the poly(carmine) modified glassy carbon electrode (GCE) is studied by cyclic voltammetry (CV)
and linear scan voltammetry (LSV). Parathion yields a well-defined reduction peak at a potential of −0.595 V on the poly(carmine)
modified GCE in pH 6.0 phosphate buffer solution (PBS). Compared with that on a bare GCE, the reduction peak current of parathion
is significantly enhanced. All the experimental parameters are optimized for the determination of parathion. The reduction
peak current is linear with the parathion concentration in the range of 5.0 × 10−8 to 1.0 × 10−5 mol L−1, and the detection limit is 1.0 × 10−8 mol L−1. 相似文献
18.
Titanium‐supported nanoscale flaky nickel electrode (nanoNi/Ti) was prepared by a hydrothermal process using hydrazine hydrate as a reduction agent. Its electrocatalytic activity as an electrocatalyst for the electrooxidation of glucose was evaluated in alkaline solutions using cyclic voltammetry (CV), chronoamperometric responses (CA) and electrochemical impedance spectra (EIS). The nanoNi/Ti electrode exhibits significantly high current density of glucose oxidation. A high catalytic rate constant of 1.67×106 cm3 mol?1 s?1 was calculated from amperometric responses on the nanoNi/Ti electrode. Low charge transfer resistances on the nanoNi/Ti in 0.5 M NaOH containing various concentrations of glucose were obtained according to the analysis for EIS. Furthermore, amperometric data show a linear dependence of the current density for glucose oxidation upon glucose concentration in the range of 0.05–0.6 mM with a sensitivity of 7.32 mA cm?2 mM?1. A detection limit of 0.0012 mM (1.2 μM) M glucose was found. Results show that the prepared nanoNi/Ti electrode presents high electrocatalytic activity for glucose oxidation. 相似文献
19.
Jing Bai Jean Chrysostome Ndamanisha Lin Liu Li Yang Liping Guo 《Journal of Solid State Electrochemistry》2010,14(12):2251-2256
The potential application of ordered mesoporous carbon (OMC)-modified glassy carbon electrode (OMC/GCE) in electrochemistry
as a novel electrode material was investigated. X-ray diffraction, transmission electron micrographs, and cyclic voltammetry
were used to characterize the structure and electrochemical behaviors of this material. Compared to GC electrode, the peak
currents of potassium ferricyanide (K3[Fe(CN)6]) increase and the peak potential separation (ΔE
p) decreases at the OMC/GC electrode. These phenomena suggest that OMC-modified GC electrode possesses larger electrode area
and faster electron transfer rate, as compared with bare GC electrode. Furthermore, riboflavin was detected using OMC/GC electrode
in aqueous solutions. The results showed that, under an optimum condition (pH 7.0), the OMC/GC electrode exhibited excellent
response performance to riboflavin in the concentration range of 4.0 × 10−7 to 1.0 × 10−6 M with a high sensitivity of 769 μA mM−1. The detection limit was down to around 2 × 10−8 M. With good stability and reproducibility, the present OMC/GC electrode was applied in the determination of vitamin B2 content in vitamin tablets, and satisfactory results were obtained. 相似文献
20.
Gilberto Maia Fernando C. Maschion Sônia T. Tanimoto Katri Vaik Uno Mäeorg Kaido Tammeveski 《Journal of Solid State Electrochemistry》2007,11(10):1411-1420
The electrochemical reduction of oxygen on glassy carbon (GC) electrodes modified with anthraquinones was studied using cyclic
voltammetry (CV) and the rotating disk electrode (RDE) technique. Two methods were used in surface modification. The first
method comprised immersion of the polished or anodically pretreated GC electrode in a solution containing 9,10-anthraquinone-2-carboxylic
acid (AQ-2-COOH) or its anion (AQ-2-COO−) in dimethylsulfoxide (DMSO) or 9,10-anthraquinone-2-ethanoic acid (AQ-2-CH2COOH) or its anion (AQ-2-CH2COO−) in N,N-dimethylformamide (DMF). Alternatively, the surface of the GC disk was modified by anodic oxidation of AQ-2-COOH or AQ-2-COO− in DMSO or AQ-2-CH2COOH in DMSO or DMF or AQ-2-CH2COO− in DMF. The modified electrodes showed electrocatalytic activity toward oxygen reduction in 0.1 M acetate buffer pH (4.8),
0.1 M phosphate buffer (pH 8) and 0.1 M NaOH. Atomic force microscopy (AFM) examination of the modified electrodes was carried
out and the differences in surface morphology of various modifications were in evidence. 相似文献