共查询到20条相似文献,搜索用时 648 毫秒
1.
Chunhai Yang Shenghui Zhang Yingxuan Liu Wensheng Huang 《Frontiers of Chemistry in China》2008,3(3):353-358
A multi-wall carbon nanotubes (MWNTs)-Nafion film-coated glassy carbon electrode (GCE) was fabricated and the electrochemical
behavior of ofloxacin on the MWNTs-Nafion film-coated GCE were investigated by cyclic voltammetry (CV), linear sweep voltammetry
(LSV) and electrochemical impedance spectroscopy (EIS). The oxidation peak current of ofloxacin increased significantly on
the MWNTs-Nafion film modified GCE compared with that using a bare GCE. This nano-structured film electrode exhibited excellent
enhancement effects on the electrochemical oxidation of ofloxacin. A well-defined oxidation peak attributed to ofloxacin was
observed at 0.97 V and was applied to the determination of ofloxacin. The oxidation peak current was proportional to ofloxacin concentration
in the ranges 1.0 × 10−8 to 1.0 × 10−6 mol/L and 1.0 × 10−6 to 2.0 × 10−5 mol/L. A detection limit of 8.0 × 10−9 mol/L was obtained for 400 s accumulation at open circuit (S/N = 3). This method for the detection of ofloxacin in human
urine was satisfactory.
__________
Translated from Chinese Journal of Applied Chemistry, 2007, 24(5): 540–545 [译自: 应用化学] 相似文献
2.
A multi-wall carbon nanotube (MWNT)/cetyl pyridine bromine (CPB) composite film modified glassy carbon electrode (GCE) was
developed for the electrochemical determination of hymecromone in phosphonate buffer. Electrochemical behaviour of hymecromone
at the composite film electrode was investigated with voltammetry. Compared with an irreversible oxidation of hymecromone
at the bare GCE, the oxidation peak current was enhanced greatly at the film electrode. Some parameters such as pH, scan rate,
accumulation potential and accumulation time were optimized. Under optimal conditions, an oxidation peak at 0.82 V was employed
to determine hymecromone electrochemically. A linearity between the oxidation peak current and the hymecromone concentration
was obtained in the range of 3.0 × 10−7 − 2.0 × 10−5 mol 1−1 with a detection limit of 8.0 × 10−8 mol 1−1. The proposed procedure was successfully applied to assay hymecromone in pharmaceutical formulation with satisfactory results.
The text was submitted by the authors in English. 相似文献
3.
Xiaojiang Zheng Dazhai Zhou Dongshan Xiang Wensheng Huang Shaofang Lu 《Russian Journal of Electrochemistry》2009,45(10):1183-1187
A poly(L-cysteine) thin film was prepared onto electrode surface via electropolymerization. In pH 7.0 phosphate buffer, L-cysteine was oxidized during the cyclic potential sweep between −0.60 and 2.00 V, forming a thin film at the glassy carbon
electrode (GCE) surface. The electrochemical behaviors of ascorbic acid at the bare GCE and the poly(L-cysteine) film-coated GCE were investigated. The oxidation peak potential of ascorbic acid shifts to more negative potential
at the poly(L-cysteine) film-modified GCE. Moreover, the oxidation peak current significantly increases at the poly(L-cysteine) film-modified GCE. These phenomena indicate that poly(L-cysteine) film shows highly-efficient catalytic activity to the oxidation of ascorbic acid. Based on this, a sensitive and
simple electrochemical method was proposed for the determination of ascorbic acid. The oxidation peak current of ascorbic
acid is proportional to its concentration over the range from 1.0 × 10−6 to 5.0 × 10−4 mol l−1. The limit of detection is evaluated to be 4.0 × 10−7 mol l−1. 相似文献
4.
Single-wall carbon nanotubes (SWNT) were dispersed into water in the presence of dicetyl phosphate (DCP), and then a SWNT-DCP
film-coated glassy carbon electrode (GCE) was constructed. The electrochemical behavior of acetaminophen at bare GCE and SWNT-DCP
modified GCE were compared, suggesting that the SWNT-DCP-modified GCE significantly enhances the oxidation peak current of
acetaminophen. A sensitive and simple electrochemical method with a good linear relationship in the range of 1.0 × 10−7–2.0 × 10−5 mol L−1, was developed for the determination of acetaminophen. The detection limit is 4.0 × 10−8 mol L−1 for 3-min accumulation. This method was successfully demonstrated with tablets. 相似文献
5.
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
6.
Lin Cui Lifang Li Shiyun Ai Huanshun Yin Peng Ju Tao Liu 《Journal of Solid State Electrochemistry》2011,15(6):1253-1261
Guanosine-5′-monophosphate (GMP) was investigated the electrochemical behaviors based on solid-phase extractionon (SPE) at
Cu-Mg-Al hydrotalcite-like compound (HTLC) modified glass carbon electrode. Cu-Mg-Al hydrotalcite-like compound (HTLC) was
proved as a new sorbent for SPE of GMP, which showed an irreversible adsorption oxidation process on the HTLC/GCE with the
oxidation peak potential located at 1.15 V (vs. SCE) in a pH 5.0 acetate buffer solution. Influencing factors of the electrochemical
behavior of GMP on the HLTC/GCE were optimized and kinetic parameters were calculated. Under the optimal conditions, with
differential pulse voltammetry (DPV), a linear relationship was obtained between the oxidation peak current and the GMP concentration
in the range from 1.0 × 10− 6 to 8.0 × 10−4 mol L−1 with the detection limit as 5.0 × 10−7 mol L−1 (signal-to-noise ratio of 3). The modified electrode surface has very good reproducibility and stability. 相似文献
7.
The electrocatalytic oxidation of quinine sulfate (QS) was investigated at a glassy carbon electrode, modified by a gel containing
multiwall carbon nanotubes (MWCNTs) and room-temperature ionic liquid of 1-Butyl-3-methylimidazolium hexafluorophate (BMIMPF6) in 0.10 M of phosphate buffer solution (PBS, pH 6.8). It was found that an irreversible anodic oxidation peak of QS with
E
pa as 0.99 V appeared at MWCNTs-RTIL/glassy carbon electrode (GCE). The electrode reaction process was a diffusion-controlled
one and the electrochemical oxidation involved two electrons transferring and two protons participation. Furthermore, the
charge-transfer coefficient (α), diffusion coefficient (D), and electrode reaction rate constant (k
f) of QS were found to be 0.87, 7.89 × 10−3 cm2⋅s−1 and 3.43 × 10−2 s−1, respectively. Under optimized conditions, linear calibration curves were obtained over the QS concentration range 3.0 × 10−6 to 1.0 × 10−4 M by square wave voltammetry, and the detection limit was found to be 0.44 μM based on the signal-to-noise ratio of 3. In
addition, the novel MWCNTs-RTIL/GCE was characterized by the electrochemical impedance spectroscopy and the proposed method
has been successfully applied in the electrochemical quantitative determination of quinine content in commercial injection
samples and the determination results could meet the requirement. 相似文献
8.
Chidan Wan Tao Liu Shuang Wei Shenghui Zhang 《Russian Journal of Electrochemistry》2008,44(3):327-331
In this work, a multi-wall carbon nanotube (MWNT) film-modified glassy carbon electrode (GCE) was constructed for the determination
of 8-hydroxydesoxyguanosine (8-OHdG). The electrochemical behaviors of 8-OHdG were examined using cyclic voltammetry (CV)
and linear sweep voltammetry (LSV), suggesting that MWNT film facilitates the electron transfer of 8-OHdG and then significantly
enhances the oxidation peak current of 8-OHdG. Finally, a sensitive and simple electrochemical method with a good linear relationship
in the range of 8.0 × 10−8 ∼ 5.0 × 10−6 mol 1−1, was developed for the determination of 8-OHdG. The detection limit is 9.0 × 10−9 mol 1−1 for 6-min accumulation. This newly-proposed method was successfully used to detect 8-OHdG in urine samples.
Published in Russian in Elektrokhimiya, 2008, Vol. 44, No. 3, pp. 351–356.
The text was submitted by the authors in English. 相似文献
9.
Tsung-Hsuan Tsai Tse-Wei Chen Shen-Ming Chen Ramiah Sarawathi 《Russian Journal of Electrochemistry》2012,48(3):291-301
The NiHCF-PEDOT, CuHCF-PEDOT and MnHCF-PEDOT films were prepared on glassy carbon electrode (GCE) by multiple scan cyclic
voltammetry and characterized using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scanning electron
microscope (SEM) techniques. The advantages of these films are demonstrated for selectivity detection of ascorbic acid using
cyclic voltammetry and amperometric method. Interestingly, the NiHCF-PEDOT and CuHCF-PEDOT modified electrodes exhibited a
wide linear response range (5 × 10−6−3 × 10−4 M, R
2 = 0.9973 and 1.8 × 10−3−1.8 × 10−2 M, R
2 = 0.9924). The electrochemical sensors facilitated the oxidation of AA but not responded to other electroactive biomolecules
such as dopamine, uric acid, H2O2, glucose. The difference is MnHCF-PEDOT/GCE that no response to AA. In addition, the NiHCF-PEDOT and CuHCF-PEDOT modified
electrodes exhibited a distinct advantage of simple preparation, specificity, stability and reproducibility. 相似文献
10.
Ying Xu Fei Wang Le Wang Fangyuan Zhao Baocheng Yang Baoxian Ye 《Journal of Solid State Electrochemistry》2012,16(4):1473-1480
A novel voltammetric sensor, based on single-walled carbon nanotubes (SWNT) dispersed in Nafion and modified glassy carbon
electrode (GCE), was fabricated and used to determine the trace amounts of dihydromyricetin (DMY). The electrochemical behavior
of DMY at this sensor was investigated in 0.1 mol L−1 sulfuric acid solutions + 0.1 mol L−1 NaCl by cyclic voltammetry and squarewave voltammetry. Compared with bare GCE, the electrode presented an excellent response
of DMY through an adsorption-controlled quasi-reversible process. Under the optimum conditions, the response peak currents
were linear relationship with the DMY concentrations in the range of 1.0 × 10−7–1.0 × 10−5 mol L−1 with a detection limit of 9 × 10−8 mol L−1. Based on this voltammetric sensor, a simple and sensitive electroanalytical method for DMY was proposed and applied to quantitative
determination of DMY in Ampelopsis grossedentata samples. In addition, the oxidation mechanism was proposed and discussed, which could be a reference for the pharmacological
action of DMY in clinical study. 相似文献
11.
Yingliang Wei Qing Zhang Chen Shao Chao Li Luping Zhang Xianli Li 《Journal of Analytical Chemistry》2010,65(4):398-403
A rapid and convenient electrochemical method is described for the determination of salbutamol based on multi-carbon nanotubes
(MWNT) film coated glassy carbon electrode (GCE). The electrochemical behavior of salbutamol at this modified electrode was studied by square wave voltammetry, which indicated
that the oxidation peak potential of salbutamol shifted on 40 mV to less positive potential and the peak current increased
4.5 fold, in contrast to that at a bare electrode. Various experimental parameters such as pH value of supporting electrolyte,
the amount of modifier, and accumulation time were optimized. Under optimal measurement conditions, there is a good linear
relationship between the peak current (I
pa) and salbutamol concentration in the range from 8.0 × 10−7 to 1.0 × 10−5 M, and the detection limit is 2.0 × 10−7 M (S/N = 3) at 2 min accumulation. The method has been successfully employed to detect salbutamol in pharmaceutical formulations. 相似文献
12.
Qiong He Tian Gan Dongyun Zheng ShengShui Hu 《Journal of Solid State Electrochemistry》2010,14(6):1057-1064
Simple and sensitive electrochemical method for the determination of nitrite, based on a nano-alumina-modified glassy carbon
electrode (GCE), is described. Nitrite yields a well-defined oxidation peak whose potential is 0.74 V at the nano-alumina-coated
GCE in 0.1 mol L−1 phosphate buffer (pH 5.0). Compared with bare GCE, the nano-alumina-modified GCE has evident catalytic effect towards the
oxidation of nitrite, and its peak current can be significantly enhanced. Some of the experimental parameters were optimized
for the determination of nitrite. The oxidation peak current was proportional to nitrite concentration in the range of 5.0 × 10−8–1.1 × 10−3 mol L−1, and a detection limit of 1.0 × 10−8 mol L−1 was obtained. This method has been successfully used to the determination of nitrite in sausage sample. Furthermore, results
obtained by the method have been compared with spectrophotometric method. 相似文献
13.
A novel electrochemical sensor for methyl parathion based on silicate– cetyltrimethylammonium bromide nanocomposite film has
been fabricated by electro-assisted deposition onto glassy carbon electrode in one-step via an electrochemical modulation
of pH at the electrode/solution interface to promote controlled gelification of tetraethylorthosilicate sol, and was characterized
with scanning electron microscopy, X-ray diffraction, and electrochemical impedance spectroscopy. The electrochemical sensing
of methyl parathion on the film-modified electrode was investigated applying cyclic voltammetry and square wave voltammetry.
Compared to the unmodified electrode, the shapes of the redox peaks were improved and the peak currents significantly increased.
Experimental parameters such as deposition time, pH value, and accumulation conditions have been optimized. A linear relationship
between the peak current and methyl parathion concentration was obtained in the range from 1.0 × 10−7 to 1.0 × 10−4 mol L−1 with a detection limit of 1.04 × 10 −8 mol L−1 (S/N = 3) after accumulation at 0 V for 120 s. The film electrode shows great promise for determination of methyl parathion in
real samples.
相似文献
14.
The polymerization of o-phenylenediamine (OPD) on l-tyrosine (Tyr) functionalized glassy carbon electrode (GCE) and its electro-catalytic oxidation towards ascorbic acid (AA)
had been studied in this report. l-Tyrosine was first covalently grafted on GCE surface via electrochemical oxidation, which was followed by the electrochemical
polymerization of OPD on the l-tyrosine functionalized GCE. Then, the poly(o-phenylenediamine)/l-tyrosine composite film modified GCE (POPD-Tyr/GCE) was obtained. X-ray photo-electron spectroscopy (XPS), field emission
scanning electron microscope (SEM), and electrochemical techniques have been used to characterize the grafting of l-tyrosine and the polymerization and morphology of OPD film on GCE surface. Due to the doping of the carboxylic functionalities
in l-tyrosine molecules, the POPD film showed good redox activity in neutral medium, and thus, the POPD-Tyr/GCE exhibited excellent
electrocatalytic response to AA in 0.1 mol l−1 phosphate buffer solution (PBS, pH 6.8). The anode peak potential of AA shifted from 0.58 V at GCE to 0.35 V at POPD-Tyr/GCE
with a greatly enhanced current response. A linear calibration graph was obtained over the AA concentration range of 2.5 × 10−4–1.5 × 10–3 mol l−1 with a correlation coefficient of 0.9998. The detection limit (3δ) for AA was 9.2 × 10−5 mol l−1. The modified electrode showed good stability and reproducibility and had been used for the determination of AA content in
vitamin C tablet with satisfactory results. 相似文献
15.
A carbon ionic liquid electrode (CILE) was fabricated by mixing N-butylpyridinium hexafluoro-phosphate (BPPF
6
) with graphite powder and further used for the investigation on the electrochemical behavior of L-tryptophan (Trp). The fabricated CILE showed good conductivity, inherent electrocatalytic ability and strong promotion to the electron transfer
of Trp. On the CILE, an irreversible oxidation peak appeared at 0.948 V (vs. saturated calomel reference electrode). For 5.0
× 10−5 M Trp the oxidation peak current increased about 5 times and the oxidation peak potential decreased on 0.092 V compared to
carbon paste electrode. The results indicated that an electrocatalytic reaction occurred on CILE. The conditions for the electrochemical
detection were optimized and the electrochemical parameters of Trp on CILE were carefully investigated. Under the selected
conditions, the oxidation peak current showed linear relationship with Trp concentration in the range of 8.0 × 10−6 ∼1.0 × 10−3 M for cyclic voltammetry and the detection limit was estimated as 4.8 × 10−6 M (3σ). The interferences of other amino acids or metal ions on the determination were tested and the proposed method was
successfully applied to the synthetic sample analysis. 相似文献
16.
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
17.
Chunya Li 《Mikrochimica acta》2007,157(1-2):21-26
Multi-wall carbon nanotubes (MWNT) were dispersed into water in the presence of dicetyl phosphate (DCP), and MWNT-DCP composite
film coated glassy carbon electrodes (GCE) were constructed. The electrochemical properties of 2-chlorophenol at a bare GCE
and MWNT-DCP modified GCE were compared. It was found that MWNT-DCP modified GCEs significantly enhance the oxidation peak
current of 2-chlorophenol and lowers its oxidation overpotential, suggesting great potential in the sensitive determination
of 2-chlorophenol. Finally, a sensitive and simple voltammetric method was developed for the determination of 2-chlorophenol.
The oxidation peak current increases linearly with the concentration in the range of 1.0 × 10−7–2.0 × 10−5 mol L−1, and the detection limit is 4.0 × 10−8 mol L−1 for 2 min accumulation. The method was successfully used to determine 2-chlorophenol in waste water samples. 相似文献
18.
We report a sensitive and convenient voltammetric method for the direct determination of 10-hydroxycamptothecin (HCPT). At
a multi-wall carbon nanotube (MWNT)-modified electrode, HCPT yields a very sensitive and well-shaped oxidation peak, which
can be used as analytical signal for HCPT determination. Compared with the poor electrochemical signal at the unmodified GCE,
the electrochemical response of HCPT at the MWNT-modified GCE was greatly improved, as confirmed by the significant peak current
enhancement. This result indicates that the MWNT-modified GCE has great potential in the sensitive determination of HCPT.
Based on this, a very sensitive and simple electrochemical method was proposed for HCPT determination after all the experimental
parameters were optimized. The newly-proposed method possesses very low detection limit (2 × 10−9 mol L−1) and wider linear range (from 1 × 10−8 to 4 × 10−6 mol L−1). Rapid and simple sample analysis is another advantage. Finally, this method was successfully demonstrated using HCPT drugs. 相似文献
19.
Multiwalled carbon nanotubes-polymeric alizarin film modified electrode was made. The electrochemical behavior of levofloxacin
hydrochloride on modified electrode was studied with cyclic voltammetry, linear sweep voltammetry and chronopotentiometry.
The results indicated that the electrical oxidation of levofloxacin hydrochloride on MWNT-PAR electrode, in HAc-NaAc buffer
solution at pH 4.2 was irreversible and was controlled by diffusion. Some important parameters m, n, D, E
D, ΔS
rc and ΔH
rc of the electrochemical process were evaluated. Good linearity relationship between peak current and its concentration in
the range of 5.0 × 10−6–1.0 × 10−4 mol l−1 was found, of which the equation was I
p(A) = −5.456 × 10−6 0.2667c, the correlative coefficient r = −0.9976 and detect limitation was 4.0 × 10−7 mol l−1. The recovery of levofloxacin hydrochloride in levofloxacin hydrochloride injection was between 94.6 and 104.7%. 相似文献
20.
Sh. Lü 《Russian Journal of Electrochemistry》2006,42(2):163-166
A glassy-carbon electrode modified with a thin film of multiwall carbon nanotubes is used for the determination of nicotinic
acid (NA). At the electrode, the latter yields a well-defined and very sensitive oxidation peak at 0.21 V (SCE). Investigation
of the electrochemical behavior of NA shows that the electrode significantly enhances the NA oxidation peak current, compared
with the non-modified electrode. Based on this, a very sensitive and simple electrochemical method is proposed for the NA
determination after the optimization of all experimental parameters. The oxidation peak current is proportional to the NA
concentration over the range 2×10−7 to 4×10−5 M, and the detection limit is 8×10−8 M after a 4-min accumulation. The relative standard deviation of 5.4% for the successive determination of 1×10−6 MNA (n=10) indicates excellent reproducibility. The analysis method is successfully demonstrated using tablet samples.
Published in Russian in Elektrokhimiya, 2006, Vol. 42, No. 2, pp. 190–195.
The text was submitted by the author in English. 相似文献