共查询到20条相似文献,搜索用时 15 毫秒
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A ruthenium oxide hexacyanoferrate (RuOHCF) modified electrode was developed. Hydrodynamic voltammetry was employed to demonstrate the remarkable electrocatalytic activity toward the oxidation of 2'-deoxyguanosine. The RuOHCF modified electrode was used as amperometric detector for 2'-deoxyguanosine determination in a FIA apparatus. The influence of various experimental conditions was explored for optimum analytical performance, and at these experimental conditions, the method exhibited a linear response range to 2'-deoxyguanosine extending from 3.8 to 252 micromol L(-1) with detection limit of 94 nmol L(-1). Applications in DNA samples were examined, and the results for determination of 2'-deoxyguanosine were in good agreement with those obtained by HPLC analysis. Studies on the kinetics of the in vitro consumption of 2'-deoxyguanosine by acetaldehyde were also performed. 相似文献
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A single-wall carbon nanotubes (SWNT)-film coated glassy carbon electrode (GCE) was described for the determination of tryptophan. In pH 2.5 Na2HPO4-citric acid buffer, tryptophan yields a well-defined and very sensitive oxidation peak at about 1.08 V at the SWNT-film coated GCE. The oxidation peak current increases greatly and the peak potential shifts toward more negative direction at the SWNT-modified GCE in contrast to that at the bare GCE. Under optimized conditions, the oxidation peak current is proportional to the concentration of tryptophan over the range from 4 x 10(-8) to 1 x 10(-5) mol/L. The detection limit is 1 x 10(-8) mol/L at 3 min of accumulation. Using the proposed method, tryptophan in the human's blood serum samples was determined. 相似文献
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Mohammad Bagher Gholivand Mehdi Khodadadian Mehdi Omidi 《Materials science & engineering. C, Materials for biological applications》2013,33(2):774-781
In this work, a bi-layer modified glassy carbon electrode (GCE) was prepared by depositing appropriate amounts of multilayered graphene (GR) on the surface of GCE, followed by electrodepositing copper hexacyanoferrate (CuHCF) nano-particles on the graphene layer. The combination of graphene and CuHCF considerably improved the current response of the GCE towards the oxidation of captopril. Studies showed that the best response of the modified electrode could be achieved within neutral pHs. At a fixed potential under hydrodynamic conditions (stirred solutions), the oxidation current is proportional to the captopril concentration and the calibration plots were linear over the concentration ranges of 0.2 to 5.8 μM and 5.8 to 480 μM. The detection limit of the method was 0.09 μM. The modified electrode was used for electrocatalytic determination of captopril in some real samples. 相似文献
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Jafarei Shayesteh Asadollahzadeh Hamideh Rastakhiz Nahid Ghazizadeh Mahdieh Mohammadi Sayed Zia 《Journal of Materials Science: Materials in Electronics》2022,33(15):11813-11824
Journal of Materials Science: Materials in Electronics - Norepinephrine (NE) is one of the most important catecholamine neurotransmitters in the central nervous system and play an important role in... 相似文献
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Binh Nguyen Thanh Dung Nguyen Nho Thanh Nguyen Mau Nhiem Dao Ngoc Dung Doan Manh Son Le Lam Quyen Nguyen Duc Vu Tuyen Tran Ngoc Tuan Nguyen Hoang Khieu Dinh Quang 《Journal of Materials Science: Materials in Electronics》2022,33(26):20884-20899
Journal of Materials Science: Materials in Electronics - Manganese ferrite/rice husk-derived activated carbon (MF/AC) was synthesized in a coprecipitation process followed by hydrothermal... 相似文献
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Electrocatalytic oxidation of guanine and DNA on a carbon paste electrode modified by cobalt hexacyanoferrate films 总被引:1,自引:0,他引:1
The electrochemical behavior of cobalt hexacyanoferrate complex adsorbed on a carbon paste electrode (CPE) and its application to the electrocatalytic oxidation of guanine and single-strand DNA (ss-DNA) in aqueous solution are investigated in this report. The modification of CPE by the adsorption of this complex results in excellent amplification of the guanine oxidation response of ss-DNA. The effects of paste composition, scan rate, DNA, and guanine concentration were studied. The detection limits of 52 and 920 ng mL(-)(1) were obtained for guanine and ss-DNA, respectively. 相似文献
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Reagentless enzyme electrode for the determination of manganese through biocatalytic enhancement. 总被引:1,自引:0,他引:1
An amperometric enzyme electrode is described for the detection and determination of manganese(II). The biosensor is based on the stimulation by manganese of the aerobic oxidation of substrates by horseradish peroxidase. A mediator, 1,2-naphthoquinone, is used as the substrate and is incorporated with the enzyme into a carbon-paste electrode. The resulting electrode acts as an enzyme-based oxygen sensor, which is sensitive to manganese. Electrochemical control of enzyme activity is achieved through substrate promotion of catalysis. Enzyme modulation by manganese can be switched on and off or adjusted through the appropriate selection of the applied potential. Currents are generated due to the bioelectrocatalytic reduction of oxygen in response to the introduction of manganese sulfate. A sustained current is achieved which is dependent on manganese concentration. Concentrations of 0.5 microM manganese or greater can be measured, and the sensor is reversible, as demonstrated by manganese removal. Biological selectivity for manganese provides a sensor which does not respond to other divalent cations tested, with the possible exception of cobalt. Reagentless, continuous sensing is achieved through substrate cycling. 相似文献
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Simultaneous determination of serotonin and dopamine at the PEDOP/MWCNTs-Pd nanoparticle modified glassy carbon electrode 总被引:1,自引:0,他引:1
Electrochemical determination of dopamine (DA) and serotonin (5-HT) have been studied at a modified glassy carbon electrode (GCE) in 0.1 M phosphate buffer solution (PBS) using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) at pH 7.4, all over the interfering biomolecule ascorbic acid (AA). The GCE was modified by palladium-functionalized, multi-walled carbon nanotubes (MWCNTs-Pd) with electrochemical deposition of poly 3,4-ethylenedioxy pyrrole (PEDOP), denoted as PEDOP/MWCNTs-Pd/GCE, and investigated by SEM and EIS experiments. The highly electrocatalytic activity of the modified electrode toward 5-HT and DA was demonstrated from the sensitive and well-separated voltammetric experiment. The oxidation peaks found were 0.165 and 0.355 mV for DA and 5-HT, respectively. The composite film shows a significant accumulation effects on two species, as well as the mutual interference among the analytes. This biosensor was best in response compared to other modified electrodes made in the same lab. The lowest detection limits were found to be 5.0 x 10(-9) and 1.0 x 10(-8) for 5-HT and DA, respectively. The respective linear ranges were determined as 1.0 x 10(-7) to 2.0 x 10(-4) and 1.0 x 10(-7) to 2.0 x 10(-4) for 5-HT and DA. 相似文献
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ABSTRACTA new sensor for the determination of nicotine is proposed based on the reduction of Cu(II)–nicotine complex at MWCNT modified carbon paste electrode. In borate buffer (pH 7.0) the reduction peak of Cu(II)–nicotine complex was observed at ? 0.05 V (versus Ag/AgCl). The increment of peak current obtained by deducting the reduction peak current of the Cu(II)–nicotine complex was rectilinear with nicotine concentration in the range of 0.05–30.0 n g mL?1, with a detection limit of 0.01 ng/mL?1. The method was applied for the sensitive quantification of nicotine in real samples with the satisfactory results. 相似文献
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M.A. El Mhammedi M. Achak M. Hbid M. Bakasse T. Hbid A. Chtaini 《Journal of hazardous materials》2009,170(2-3):590-594
In this work, determination of cadmium(II) using square wave voltammetry (SWV) was described. The method is based on accumulation of these metal ions on kaolin platinum electrode (K/Pt). The K/Pt performance was optimized with respect to the surface modification and operating conditions. The optimized conditions were obtained in pH of 5.0 and accumulation time of 25 min. Under the optimal conditions, the relationship between the peak current versus concentration was linear over the range of 9 × 10−8 to 8.3 × 10−6 mol L−1. The detection limit (DL, 3σ) was 5.4 × 10−9 mol L−1. The analytical methodology was successfully applied to monitor the Cd(II) content in natural water. Interferences were also evaluated. 相似文献
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通过热丝化学气相沉积(HFCVD)的方法,以钽(Ta)为衬底,三氧化二硼(Be2O3)为硼源,制备掺硼金刚石(BDD)薄膜.并采用共价键合法进一步制得壳聚糖修饰BDD薄膜电极.以此修饰电极为工作电极,在0.1mol/L,pH=4的磷酸氢二钠缓冲液中对Cu2+进行检测.实验表明,Cu2+在4.0×10-7~1.0×10-... 相似文献
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The sensitive determination of cyanide in wastewaters using modified GC electrode with silver hexacyanoferrate nanoparticles (SHFNPs) immobilized on multiwall carbon nanotube (MWCNT) was reported. The immobilization of SHFNPs on MWCNT was confirmed by transmission electron microscopy (TEM). The TEM image showed that the SHFNPs retained the spherical morphology after immobilized on MWCNT. The size of SHFNPs was examined around 27 nm. The GC/MWCNT-SHFNPs was used for the determination of cyanide in borax buffer (BB) solution (pH 8.0). Using square wave voltammetry, the current response of cyanide increases linearly while increasing its concentration from 40.0 nM to 150.0 μM and a detection limit was found to be 8.3 nM (S/N=3). The present modified electrode was also successfully used for the determination of 5.0 μM cyanide in the presence of common contaminants at levels presenting in industrial wastewaters. The practical application of the present modified electrode was demonstrated by measuring the concentration of cyanide in industrial wastewater samples. Moreover, the studied sensor exhibited high sensitivity, good reproducibility and long-term stability. 相似文献
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Cyclic voltammetry of a mixture containing 0.2 mM Na2IrCl6, 0.1 mM PdCl2, 0.2 M K2SO4, and 0.1 M HCl between 1.2 and -0.3 V vs Ag/AgCl for five cycles at 50 mV s-1 yields a stable film on a glassy carbon electrode. The reduction of hydrogen peroxide in 0.1 M KCl is diffusion controlled at that modified electrode. Calibration curves obtained at a 100 mV s-1 scan rate are linear in the range 0.2-1.8 mM H2O2. The slope, 28 microA L mmol-1, is independent of film thickness. Since dissolved oxygen is reduced at about the same potential as H2O2, -0.3 V, at the modified electrode, it will act as an interferent in solutions that are not deaerated; however, the currents are additive. A second limitation of the described procedure is that with the KCl electrolyte the immobilized film must be reoxidized prior to each measurement. Preliminary data are described which suggest that this problem is alleviated by switching to a basic supporting electrolyte. 相似文献
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通过改变有机酸与无机酸的配比研究合成高电导率聚苯胺的最佳条件,使用硝酸对活性炭进行改性,测定活性炭的沉降质量和活化指数并筛选出吸附性能最佳的改性活性炭,将最佳工艺条件下合成的聚苯胺与改性活性炭进行复合制备了聚苯胺/改性活性炭复合电极材料。通过X射线衍射、扫描电子显微镜和电化学性能测试对复合电极材料的结构和性能进行表征和研究。结果表明:用质量分数3%的硝酸改性的活性炭掺杂聚苯胺,二者的相容性最好,且改性活性炭含量为25.5%(质量分数)时,制备的复合电极材料比电容最大,为282F/g,比纯聚苯胺的比容量(210F/g)增加了34.3%。电化学性能测试表明,聚苯胺/改性活性炭复合电极材料内阻小,阻抗高,电容性能优良。 相似文献