多壁碳纳米管修饰玻碳电极伏安法测定氯霉素

研究了氯霉素(CAP)在多壁碳纳米管修饰玻碳电极上的电化学行为.发现在pH=2.0的0.1 mol/LKCl-HCl底液中,CAP在该修饰电极上有一灵敏的还原峰(Ep=-0.36 V vs.Ag/AgCl),峰电流与CAP浓度成正比,线性范围为6.0×10-6~2.7×10-4mol/L,检测限达3.0×10-6mol/L.该方法灵敏、准确,用于模拟样品和实际样品的测定,结果满意.     

纳米金修饰玻碳电极测定邻苯二酚

采用恒电位沉积方法将HAuCl4直接还原成纳米金并修饰于玻碳电极表面,制备了对邻苯二酚具有电催化氧化作用的纳米金修饰电极。邻苯二酚在该修饰电极上发生一可逆的氧化还原反应。在磷酸盐缓冲溶液(pH 7.5)中,当邻苯二酚的浓度为3.0×10-3mol.L-1时,与裸玻碳电极相比,其Epa负位移了170 mV,Epc正位移了50 mV,ΔE下降为60 mV,且峰电流显著增大,氧化峰电流与邻苯二酚浓度在5.0×10-6~4.2×10-3mol.L-1范围内呈线性关系,相关系数为0.997 6,检出限(3σ)为5.0×10-7mol.L-1。在浓度为5.0×10-4mol.L-1测得RSD(n=10)为2.9%,回收率在98.0%~101.0%之间。     

单壁碳纳米角电化学应用

单壁碳纳米角具有独特的性质,如大的比表面积、良好的导电性和生物相容性等,在某些领域应用广泛. 本文结合作者课题组工作,综述了单壁碳纳米角电化学应用现状,并展望其今后的发展趋势.     

Electrochemical Behavior and Voltammetric Determination of Curcumin at Electrochemically Reduced Graphene Oxide Modified Glassy Carbon Electrode

This work presents a sensitive voltammetric method for determination of curcumin by using a electrochemically reduced graphene oxide (ERGO) modified glass carbon electrode (GCE) in 100 mM KCl‐10 mM sodium phosphate buffer solution (pH 7.40). The electrochemical behaviors of curcumin at ERGO/GCE were investigated by cyclic voltammetry, suggesting that the ERGO/GCE exhibits excellent electrocatalytic activity towards curcumin, compared with bare GCE and GO/GCE electrodes. The electrochemical reaction mechanisms of curcumin, demethoxycurcumin and bisdemethoxycurcumin at the ERGO/GCE were also investigated and discussed systematically. Under physiological condition, the modified electrode showed linear voltammetric response from 0.2 μM to 60.0 μM for curcumin, with the detection limit of 0.1 μm. This work demonstrates that the graphene‐modified electrode is a promising strategy for electrochemical determination of biological important phenolic compounds.     

肌红蛋白在磷脂-月桂酸修饰的玻碳电极上的电化学行为及其分析应用

报道了肌红蛋白(Mb)在磷脂、月桂酸修饰的玻碳电极上的电化学行为 ,在 +0.2～ -0.7V(vs.Ag/AgCl)电位范围内 ,于pH6.0的0.01mol·L-1的KH2PO4、Na2HPO4底液中 ,肌红蛋白产生不可逆的还原电流峰 ;还原峰电流与肌红蛋白浓度在2.25×10-8 ～1.40×10-6 mol·L-1 范围内呈良好线性关系 ;线性回归方程为Ip(μA)=-0.01419 +0.2382cMb(10 -7mol·L -1) ,线性回归系数r(10)为0.998 ,检出限为1.20×10 -8mol·L -1,该电极可作为检测肌红蛋白的新型的高灵敏度电化学生物传感器。     

Electrochemical Detection of NADH,Cysteine, or Glutathione Using a Caffeic Acid Modified Glassy Carbon Electrode

A modified electrode was prepared using electrodeposition methods to immobilize caffeic acid (CAF) onto the surface of a glassy carbon electrode (GCE) to create a polymer suitable for biosensor development. The polymer film coverage of the surface bound species was further optimized using electrodeposition methods, thus increasing the surface coverage to ca. 10^?9 mol cm^?2. Using cyclic voltammetry, the modified carbon electrode was used to facilitate and observe the electrocatalytic oxidation of coenzymes such as NADH, cysteine, and glutathione at different concentrations. A calibration curve was determined in each case within the concentration range; 300 nM to 10 mM, with the limits of detection (LOD) of 246 µM, 99 µM, 2.2 µM for NADH, cysteine, and glutathione respectively.     

Voltammetric Determination of Arsenic with Modified Glassy Carbon Electrode

In this study, glassy carbon electrode modified with nano gold‐crystal violet film has been used to detect arsenite (As (III)) in a model system and in groundwater samples. The modified electrode was characterized by scanning electrochemical microscopy (SECM) and electrochemical impedance spectroscopy (EIS). Using voltammetric measuring technique, linear response was obtained in a concentration range of 2.0–22.0 μM. The arsenite concentrations in groundwater samples varied between 2.4 μM to 4.8 μM. The sensitivity of the modified electrode for As (III) detection was 5.6 μA/μM cm² and 0.8 μM concentration was found as lower limit of detection (LOD). The accuracy of the method was checked with standard method anodic stripping voltammetry (ASV). Groundwater samples were characterized with dynamic (DLS) and electrophoretic (ELS) light scattering measurements which have shown that particles present in different samples differ in size distribution and zeta potential which did not interfere with As (III) detection.     

多壁碳纳米管修饰玻碳电极测定乙炔雌二醇

多壁碳纳米管修饰玻碳电极测定乙炔雌二醇;多壁碳纳米管;乙炔雌二醇;化学修饰电极;电化学测定     

Electrochemical Behavior and Determination of L‐Tyrosine at Single‐walled Carbon Nanotubes Modified Glassy Carbon Electrode

Based on single‐walled carbon nanotubes (SWCNTs) modified glassy carbon electrode (GCE/SWCNTs), a novel method was presented for the determination of L ‐tyrosine. The GCE/SWCNTs exhibited remarkable catalytic and enhanced effects on the oxidation of L ‐tyrosine. In 0.10 mol/L citric acid‐sodium citrate buffer solution, the oxidation potential of L ‐tyrosine shifted negatively from +1.23 V at bare GCE to +0.76 V at GCE/SWCNTs. Under the optimized experimental conditions, the linear range of the modified electrode to the concentration of L ‐tyrosine was 5.0×10^?6–2.0×10^?5 mol/L (R₁=0.9952) and 2.7×10^?5–2.6×10^?4 mol/L (R₂=0.9998) with a detection limit of 9.3×10^?8 mol/L. The kinetic parameters such as α (charge transfer coefficient) and D (diffusion coefficient) were evaluated to be 0.66, 9.82×10^?5 cm² s^?1, respectively. And the electrochemical mechanism of L ‐tyrosine was also discussed.     

盐酸二甲双胍在玻碳电极上的伏安行为及测定

对盐酸二甲双胍在玻碳电极上的伏安行为进行了研究,发现在0.3 mol/L NaOH底液中,盐酸二甲双胍于-0.37 V产生良好的还原峰,其浓度在1.0×10-9～1.0×10-6 mol/L范围内与峰电流有良好的线性关系,该方法具有很强的抗干扰能力。实验测定了盐酸二甲双胍片剂中的盐酸二甲双胍含量。测得糖尿病人尿液中盐酸二甲双胍含量为7.73×10-4 mol/L,测得RSD为3.6%,回收率93.0％～105.0%。     

Electrochemical Determination of Tannins Using Multiwall Carbon Nanotubes Modified Glassy Carbon Electrode

A novel chemically modified electrode is prepared on the basis of the attachment of multiwall carbon nanotubes (MWNTs) to the surface of a glassy carbon electrode (GCE) in the presence of a hydrophobic surfactant. The electrochemical behavior of tannins at the MWNTs-modified GCE is investigated. Tannins yield a well-defined oxidation at about 0.30 V (SCE) at the MWNTs-modified GCE. MWNT-film shows remarkable enhancement effect on the oxidation peak current of tannins. The experimental parameters are optimized, and a direct electrochemical method to detect tannins is proposed. The oxidation peak current is proportional to the concentration of tannins over the range from 4 × 10^–7 to 2 × 10^–4 M, and the detection limit is 1 × 10^–7 mol/l after 5 min of accumulation. The relative standard deviation of 6% for determination of 2 × 10^–6 mol/l tannins indicates excellent reproducibility. The analysis method is demonstrated by using tea and Chinese gall samples.     

Electrochemical Determination of Pentachlorophenol Using a Glassy Carbon Electrode Modified with a Film of CuS Nanocomposite-Chitosan

A new electrochemical sensor was fabricated by modifying the glass carbon electrode surface with CuS nanocomposites and chitosan for the determination of pentachlorophenol. CuS nanocomposites obtained by a solvothermal method were composed primarily of CuS with hexagonal phase and Cu₂Cl(OH)₃ with a tetragonal phase. The results indicated that CuS nanocomposites possessed good electrochemical activity. After optimizing the experimental conditions, the linear dependence of current vs. pentachlorophenol concentration was reached in a range from 1.88 × 10^?6–7.50 × 10^?5 mol/L pentachlorophenol, and the detection limit was 6.25 × 10^?7 mol/L. The electrode displayed a high degree of stability and reproducibility. A new, simple, rapid, and highly sensitive electrochemical detection method of pentachlorophenol was established.     

用多壁碳纳米管修饰玻碳电极为工作电极循环伏安法测定辛硫磷

将多壁碳纳米管(MWCNT′s)置于硝酸-硫酸(1+1)溶液中回流6 h使之净化及功能化。取MWCNT′s 5 mg置于超纯水10 mL中经超声振荡20 min制得其悬浮液,取悬浮液10μL滴加在玻碳电极(GCE)表面,经自然干燥后即得用MWCNT′s修饰的玻碳电极(MWCNT′s/GCE)。基于此修饰电极对辛硫磷的催化还原反应,提出了蔬菜中辛硫磷的循环伏安测定法,在pH 4的乙酸盐支持电解质溶液中,在电位0.78 V(对SCE)处可见明显的还原峰,且其峰电流值与辛硫磷浓度在5.0×10-8~1.0×10-6mol.L-1之间呈线性关系。应用此法分析了两件蔬菜样品,并以此试样为基体加入标准溶液对方法进行回收及精密度试验,测得其回收率的平均值和相对标准偏差(n=5)分别依次为100.3%,96.5%及3.7%,3.2%。     

Electrochemical Detection of Steroid Hormones Using a Nickel‐Modified Glassy Carbon Electrode

This paper demonstrates the development of an analytical method for detecting steroid hormones by coupling HPLC to electrochemical detection, using a nickel‐modified glassy carbon electrode. The method was evaluated in terms of sensitivity, linear dynamic range, limit of detection, and response stability. The developed method exhibited good figures of merit for the steroid hormones studied with no evidence of electrode fouling. As an example, the limit of detection (S/N=3) for E3 was 0.10 µM and the response precision (n=5) was 0.6 %. The application of the method for the analysis of a real river water sample is demonstrated.     

硫化物在乙酰二茂铁修饰碳糊电极上的电化学行为及电分析

研究了S2-在乙酰二茂铁(AFc)修饰碳糊电极(AFc/CPE)上的电催化氧化行为及其电化学分析方法。实验结果表明,AFc/CPE对S2-的电化学氧化具有良好的催化作用。用计时电流法(CA)测定了S2-在AFc/CPE上的电催化氧化反应速率常数k为(2.60±0.05)×105 L.mol-1.s-1。用方波伏安法(SWV)测得催化氧化峰电流与S2-的浓度在5.0×10-5～1.0×10-3 mol.L-1范围内呈良好线性关系,检出限(S/N=3)为1.3×10-7 mol.L-1,同时运用SWV法对造纸废水水样中S2-的含量进行了电化学定量测定。     

芦丁在玻碳电极上的阳极伏安行为及其测定

本文应用线性扫描伏安法，微分脉冲伏安和循环伏安法对芦丁在玻碳电极上的阳极伏安行为进行了研究。     

盐酸川芎嗪在玻碳电极上的伏安行为及应用

对盐酸川芎嗪在玻碳电极上的伏安行为进行了研究 ,在 0 .0 1mol LKCl～HCl(pH 2 .2 )底液中盐酸川芎嗪于 -0 .5 5V处产生良好的阴极还原峰 ,其浓度在 1 0× 1 0 - 6 ～ 1 .0× 1 0 - 4mol L范围内与峰电流呈线性关系。该方法具有很强的抗干扰能力 ,操作简便、快速。用于注射液中盐酸川芎嗪的测定 ,结果满意。对电极反应机理也进行了探讨。     

用银-色氨酸复合膜修饰玻碳电极循环伏安法测定去甲肾上腺素

在含有1.0mmol.L-1硝酸银、5.58×10-2 mol.L-1色氨酸的溶液中,于-0.8～1.8V(vs.Ag/AgCl)电位下,在玻碳电极表面电沉积一层银-色氨酸复合膜,制得银-色氨酸复合膜修饰玻碳电极(Ag-TRY/GCE)。采用扫描电镜对电极表面的性能进行表征,循环伏安法对其电化学性能进行研究。试验发现:在pH 6.0磷酸盐缓冲溶液中,去甲肾上腺素(NE)在修饰电极出现一对明显的氧化还原峰,氧化峰电位为0.306V,还原峰电位为0.368V,提出了用循环伏安法测定NE的方法。在试验条件下,氧化峰电流与去甲肾上腺素浓度在3.4×10-7～8.3×10-6 mol.L-1和8.3×10-6～1.1×10-4 mol.L-1两段范围内呈线性关系,检出限(3S/N)为4.3×10-8 mol.L-1。修饰电极用于药物中去甲肾上腺素的测定,加标回收率在95.6%～99.4%之间。     

Electrochemical Behavior and Voltammetric Determination of Diclofenac at a Multi-Walled Carbon Nanotube-Ionic Liquid Composite Modified Carbon Ceramic Electrode

This work describes the electrochemical behavior of diclofenac on the surface of a carbonceramic electrode (CCE) modified with multi-walled carbon nanotubes (MWCNT) and an ionic liquid (IL) composite. The MWCNT-IL composite showed an enhancement effect in the electro-oxidation of diclofenac with respect to a bare carbon ceramic electrode. Based on the experimental outcomes, a possible mechanism for the electro-oxidation of diclofenac is proposed and discussed. Under the optimized experimental conditions, the MWCNT-IL CCE showed a linear response to diclofenac over the concentration range 50 nM–20 µM with a detection limit of 27 nM. The developed diclofenac sensor showed good stability, sensitivity, and reproducibility in the measurement of diclofenac in human blood plasma samples.     

磷脂-月桂酸膜修饰玻碳电极测定多巴胺及其电化学行为

本文报道了多巴胺 (DA)在磷脂 -月桂酸修饰的玻碳电极上的电化学行为 ,在+ 0 .7～ -0 .4V(vs.Ag/ Ag Cl)电位范围内 ,于 p H 6.4的 0 .0 1 mol/ L的 KH2 PO4 -Na2 HPO4 底液中 ,多巴胺产生很灵敏的氧化峰电流。氧化峰电流与多巴胺浓度在 3 .1× 1 0 - 7～ 1 .2× 1 0 - 4mol/ L范围内呈良好线性关系。该电极可作为检测多巴胺的新型的高灵敏度电化学生物传感器