双酚A在纳米二氧化铈修饰碳糊电极上的电化学行为及应用

采用固相合成法制备了纳米二氧化铈并对其进行了表征.研究了环境激素双酚A在CeO<,2>修饰碳糊电极上的电化学行为.在0.01 mol/L(pH 9.18)的硼砂溶液中,BPA于0.40 V处产生一不可逆的氧化峰,与裸碳糊电极相比,BPA在修饰电极上的电流响应明显增大,据此建立了测定塑料样品中BPA的线性扫描伏安法.线性...     

PMB/n-ZnS修饰碳糊电极对双酚A的电化学行为研究

将纳米硫化锌(n-Zn S)作为载体,通过掺杂-电聚合的方式制备出聚亚甲基蓝/纳米硫化锌复合膜修饰电极(PMB/n-Zn S/CPE)。运用循环伏安法(CV)和电子扫描显微镜(SEM)对复合膜进行表征,其元素组成借助于X射线能谱仪(EDS)进行了分析,进而研究了双酚A在该修饰电极上的电化学行为,探讨了最佳实验条件。掺杂了n-Zn S颗粒后的复合膜呈现出三维空间结构,对双酚A的电催化氧化性能显著提高,峰电流是裸电极上的2.5倍,其氧化峰电流与浓度在1.0×10-5~5.0×10-4mol/L范围内呈现出良好的线性关系,检出限为1.0×10-6mol/L。     

介孔碳纳米纤维修饰电极用于黄酮类化合物芦丁的电化学测定

制备了新型的介孔碳纳米纤维修饰热解石墨电极(MCNF/PGE),并将其用于芦丁含量的测定。用循环伏安法、交流阻抗谱法、示差脉冲伏安法研究了该修饰电极膜性能及芦丁在该修饰电极上的电化学行为。结果表明,修饰电极可有效促进探针离子[Fe(CN)6]3-/4-在电极表面的电子传递;芦丁在该修饰电极表面的电化学过程受扩散控制。由于MCNFs大量的石墨边缘缺陷、大比表面积以及介孔结构,与裸电极相比,该修饰电极对芦丁呈现出很高的电催化活性,芦丁阳极峰电流约为裸电极上的18倍。在最佳实验条件下,芦丁的氧化峰电流(Ipa)与其浓度(c)在2.0×10-8～1.2×10-6mol/L范围内呈良好的线性关系,检出限(S/N=3)为5.0×10-9mol/L,线性系数r2=0.999。此外,计算了电荷转移系数(α)、标准速率常数(ks),并推测了芦丁的电化学氧化还原机理。该修饰电极易于制备、可再生,重复性及稳定性良好,可作为一种高灵敏度的电化学传感器应用于芦丁片剂中芦丁的含量测定。     

甲巯咪唑基于血红素修饰碳糊电极的电化学测定

制备了一种血红素修饰碳糊电极,用循环伏安法研究了甲巯咪唑在该修饰碳糊电极上的电化学响应特征,并对各实验参数进行了优化.相对于裸碳糊电极,甲巯咪唑在血红素修饰碳糊电极上的氧化峰电位明显负移,氧化峰电流大大提高,说明血红素对甲巯咪唑的氧化具有一定的促进作用.微分脉冲伏安实验结果表明,甲巯咪唑的氧化峰电流与其浓度在4×10-7 ～2×10-4 mol/L范围内呈良好的线性关系,检出限(S/N=3)为2×10-7 mol/L.该修饰碳糊电极显示了较好的抗干扰能力,尿酸几乎不干扰测定.用于实际尿样中甲巯咪唑的加标回收测定,结果满意.     

静电纺氮硫共掺杂碳纳米纤维修饰电极用于电化学发光检测盐酸地芬尼多

以聚丙烯腈(PAN)为碳源,Na2S2O3为硫源,采用静电纺丝和高温碳化,制备了氮硫共掺杂多孔碳纳米纤维(N,S-SCNFs).采用场发射扫描电镜、透射电镜、比表面及孔隙度分析仪、X射线衍射仪对材料进行表征.将N,S-SCNFs悬浊液滴涂在裸玻碳电极(GCE)表面,得到N,S-SCNFs/GCE修饰电极.采用循环伏安法...     

二氧化硅/金复合膜修饰玻碳电极用于双酚A的检测

该文制备了二氧化硅/金复合膜修饰玻碳电极(SiO_2/Au/GCE),提出了一种简便检测双酚A(BPA)的电化学分析方法。采用扫描电镜(SEM)和红外光谱(FT-IR)对SiO_2和SiO_2/Au的形貌和结构进行了表征,循环伏安法(CV)和交流阻抗法(EIS)研究了SiO_2/Au/GCE的表面电化学特性,同时用CV、计时库仑法(CC)、控制电位电解库仑法、线性扫描伏安法(LSV)和差分脉冲伏安法(DPV)等研究了BPA在SiO_2/Au/GCE上的电化学行为,优化了实验参数,并得到电化学动力参数。实验发现:SiO_2/Au/GCE对BPA具有良好的电催化活性,BPA在该修饰电极上的氧化峰电流为GCE上的3倍,且BPA在SiO_2/Au/GCE上的氧化过程为2电子2质子的完全不可逆电极过程。在最佳条件下,BPA的氧化峰电流分别在0.01~0.50μmol/L和0.50~25μmol/L浓度范围内呈良好的线性关系,检出限为1.9×10-8mol/L。用于一次性手套中BPA含量的测定,回收率为98.9%~105.3%,与高效液相色谱法(HPLC)进行对照,结果满意。     

植酸镁基修饰电极的制备及其对双酚A的检测

采用水热法制备了植酸基材料（PAC）和植酸镁基复合材料（PA-Mg）,并用扫描电镜（SEM）, X射线衍射（XRD）, X射线光电子能谱（XPS）对PAC和PA-Mg进行了表征。分别采用循环伏安法（CV）和交流阻抗法（EIS）探究了2种材料的电化学性能,采用微分脉冲伏安法（DPV）探究了2种材料对双酚A(BPA)的响应。结果表明,相比PAC, PA-Mg表现出更优异的电化学性能,分别以PA-Mg和PAC为修饰材料,以玻碳电极（GCE）为基底电极构建PA-Mg/GCE和PAC/GCE。PA-Mg/GCE对BPA的响应电流值是PAC/GCE的2.2倍。PA-Mg/GCE在最佳检测条件下对BPA的线性响应范围为0.8～50μmol/L,检出限为0.1μmol/L,相关系数为0.996。将PA-Mg/GCE用于模拟废水中BPA浓度的测定,加标回收率在92.5%～101.5%之间。     

纳米CeO2修饰碳糊电极微分脉冲伏安法对盐酸克伦特罗的测定

研究了盐酸克伦特罗(CLB)在纳米CeO2修饰碳糊电极上的电化学行为.结果表明:在0.10 mol·L-1的HClO4溶液中,CLB于+0.40 V(vs SCE)左右处产生1对准可逆的氧化还原峰.与裸碳糊电极相比,CLB在修饰电极上的电流响应明显增大,据此建立了尿样中CLB的微分脉冲伏安测定方法.线性范围为5.0×10-9 ～6.0×10-6 mol·L-1(r=0.998 2,n=7),检出限为2.5×10-9 mol·L-1(3sb),加标回收率为96% ～104%.     

基于DNA-单壁纳米碳管复合修饰电极的双酚A电化学传感器

利用单壁纳米碳管(SWNT)优异的电学性能和催化特性以及DNA特定的分子识别功能,成功构建了一种高灵敏度、快速测定双酚A(BPA)的电化学传感器。在pH7.0的磷酸缓冲溶液中,BPA在SWNT-DNA复合修饰电极上的氧化电流信号是空白电极上的10倍。在10～200 mV/s扫速范围内,氧化峰电流与扫速呈线性关系,表明该氧化过程受吸附控制,通过理论计算,BPA在修饰电极上的反应是一个双电子和双质子过程。在最优的实验条件下,采用差分脉冲伏安法(DPV)对BPA进行测定,氧化电流与BPA浓度在1.0×10-8～2.0×10-5mol/L范围内呈良好的线性关系(r=0.9954),检出限为5.0×10-9mol/L(S/N=3)。该方法初步用于实际样品分析,BPA的加标回收率为93.1%～109.3%。     

还原氧化石墨烯-多壁碳纳米管复合膜负载金纳米粒子修饰玻碳电极检测双酚A

以水合肼为还原剂,采用均相还原法制备还原氧化石墨烯-多壁碳纳米管复合材料(rGO-MWCNTs),通过滴涂法将其修饰到玻碳电极(GCE)表面.以此复合材料为载体,采用电化学方法制备了金纳米粒子-还原氧化石墨烯-多壁碳纳米管复合膜修饰电极(AuNPs-rGO-MWCNTs/GCE).通过扫描电镜(SEM)、EDS能谱技术和电化学方法对此电极进行了表征.研究了双酚A在修饰电极上的电化学行为.结果表明,此电极对双酚A的电极过程具有良好的电化学活性,在0.10 mol/L PBS溶液(pH 7.0)中,微分脉冲伏安法测定双酚A的线性范围为5.0 × 10-9~1.0 × 10-7 mol/L和1.0 × 10-7~2.0 × 10-5 mol/L,检出限为1.0 ×10-9 mol/L(S/N=3). 将此电极用于模拟水样和超市购物小票样品中双酚A含量的测定,加标回收率分别为97%~110%和98%~104%.     

Simultaneous Electrochemical Determination of Hydroquinone and Bisphenol A using a Carbon Paste Electrode Modified with Silver Nanoparticles

In this paper, a rapid and sensitive modified electrode for the simultaneous determination of hydroquinone (HQ) and bisphenol A (BPA) is proposed. The simultaneous determination of these two compounds is extremely important since they can coexist in the same sample and are very harmful to plants, animals and the environment in general. A carbon paste electrode (CPE) was modified with silver nanoparticles (nAg) and polyvinylpyrrolidone (PVP). The PVP was used as a reducing and stabilizing agent of nAg from silver nitrate in aqueous media. The nAg‐PVP composite obtained was characterized by transmission electron microscopy and UV‐vis spectroscopy. The electrochemical behavior of HQ and BPA at the nAg‐PVP/CPE was investigated in 0.1 mol L⁻¹ B−R buffer (pH 6.0) using cyclic voltammetry (CV) and square wave voltammetry (SWV). The results indicate that the electrochemical responses are improved significantly with the use of the modified electrode. The calibration curves obtained by SWV, under the optimized conditions, showed linear ranges of 0.09–2.00 μmol L⁻¹ for HQ (limit of detection 0.088 μmol L⁻¹) and 0.04–1.00 μmol L⁻¹ for BPA (limit of detection 0.025 μmol L⁻¹). The modified electrode was successfully applied in the analysis of water samples and the results were comparable to those obtained using UV‐vis spectroscopy.     

Voltammetric Determination of Selected Aminoquinolines Using Carbon Paste Electrode

Optimum conditions have been found for voltammetric determination of mutagenic 5‐aminoquinoline, 6‐aminoquinoline and 3‐aminoquinoline by differential pulse voltammetry and adsorptive stripping differential pulse voltammetry on carbon paste electrode. The lowest limits of determination were found for adsorptive stripping differential pulse voltammetry in 0.1 mol dm^?3 H₃PO₄ (5×10^?7 mol dm^?3 , 1×10^?7 mol dm^?3, and 1×10^?7 mol dm^?3 for 5‐aminoquinoline, 6‐aminoquinoline and 3‐aminoquinoline, respectively). The possibility to determine mixtures of 8‐aminoquinoline with 3‐aminoquinoline or 5‐aminoquinoline or 6‐aminoquinoline, and mixtures of 5‐aminoquinoline with 3‐aminoquinoline or 6‐aminoquinoline by differential pulse voltammetry was verified. Binary mixtures of 8‐aminoquinoline with 3‐aminoquinoline or 6‐aminoquinoline, and of 3‐aminoquinoline with 5‐aminoquinoline could be successfully analyzed.     

头孢氨苄在碳糊电极上的电化学行为及其分析研究

用循环伏安法和线性扫描伏安法研究了头孢氨苄在碳糊电极上的电化学行为,考察了不同电解质溶液、pH以及扫描速率等的影响。实验表明:在2.0 mol·L-1HCl支持电解质中,头孢氨苄的降解产物在-0.45 V(vs.SCE)处的电化学还原反应为2电子与2质子参加的受吸附控制的不可逆过程。还原峰电流与头孢氨苄的浓度的平方根在1.8×10-8～3.0×10-4mol·L-1范围内呈良好的线性关系,回收率在95.7%～101.5%范围,检出限(S/N=3)为1.0×10-8mol·L-1。并探讨了头孢氨苄在电极上的反应机理。     

Determination of Bisphenol A Using an Electrochemical Sensor Based on a Molecularly Imprinted Polymer-Modified Multiwalled Carbon Nanotube Paste Electrode

A novel electrochemical sensor for bisphenol A was developed through the combination of a molecular imprinting technique with a multiwalled carbon nanotube paste electrode. A molecularly imprinted polymer and nonimprinted polymer were synthesized in the presence and absence of bisphenol A, and then used to prepare the electrode. The bisphenol A imprinted polymer was applied as a selective recognition element in the electrochemical sensor. Differential pulse voltammetry was used to characterize the electrochemical behavior of bisphenol A at the modified electrodes. The results showed that the imprinted sensor had highest response for bisphenol A. Parameters including the carbon paste composition, pH, and adsorption time for the imprinted sensor were optimized. Under the optimized conditions, the differential pulse voltammetry peak current was linear with the concentration of bisphenol A from 0.08 to 100.0 µM, with a detection limit of 0.022 µM. The imprinted sensor for bisphenol A exhibited good selectivity, stability, and reproducibility. This sensor was successfully used for the determination of bisphenol A in real water samples.     

麦饭石修饰碳糊电极伏安法测定克林霉素

在pH=9的磷酸盐缓冲溶液(PBS)中,用麦饭石修饰碳糊电极循环伏安法研究了克林霉素的电化学性质,并讨论了影响克林霉素测定的各种因素,得到了其测定的最佳实验条件。克林霉素的氧化峰电位是0.80V,氧化峰电流与克林霉素的浓度在3.25×10-6～1.10×10-4 mol.L-1范围内呈良好的线性关系。该测定方法的检出限(S/N=3)为5.0×10-7 mol.L-1。用标准加入法测定回收率范围在94.9%～101.4%。克林霉素在0.80V处的氧化为1电子、1质子参加的受扩散控制的不可逆过程。克林霉素的电化学测定方法能很好地用于实际样品的测定而且结果与药典法一致。     

Electrochemical Reduction and Voltammetric Determination of Metronidazole Benzoate at Modified Carbon Paste Electrode

Abstract

A metalloporphyrin incorporated carbon paste sensor has been developed for the determination of metronidazole benzoate (MTZB). Zn(II) complex of 5,10,15,20-tetrakis (3-methoxy-4-hydroxy phenyl) porphyrin (TMHPP) was used as the active material. The MTZB gave a well-defined reduction peak at?0.713 V in 0.1 mol l^?1 phosphate buffer solution of pH around 7. Compared with bare carbon paste electrode (CPE), the TMHPP Zn(II) modified electrode significantly enhanced the reduction peak current of MTZB as well as lowered its reduction potential. Under optimum conditions the reduction peak current was proportional to MTZB concentration over the range 1 × 10^?3 mol l^?1 to 1 × 10^?5 mol l^?1. The detection limit was found to be 4.36 × 10^?6 mol l^?1. This sensor has been successfully applied for the determination of MTZB in pharmaceutical formulations and urine samples.     

化学修饰碳糊电极微分脉冲伏安法测定岩矿样品中的钯

制备了一种含硫脲基螯合树脂的碳糊修饰电极 ,并将其用于矿样中痕量钯的测定。通过实验选定了电极预处理及测定的最佳条件 ,并对影响峰电流的各种因素及电极的性能进行了讨论。在最佳条件下 ,测定钯的浓度范围为 8.66× 1 0 - 9～ 8.66×1 0 - 5mol/L,检出限为 9.84× 1 0 - 10 mol/L     

Electrochemical Analysis of D‐Penicillamine Using a Carbon Paste Electrode Modified with Ferrocene Carboxylic Acid

The electrochemical behavior of D ‐penicillamine (D ‐PA) studied at the surface of ferrocene carboxylic acid modified carbon paste electrode (FCAMCPE) in aqueous media using cyclic voltammetry and double step potential chronoamperometry. It has been found that under optimum condition (pH 7.00), the oxidation of D ‐PA at surface of such an electrode is occurred about 420 mV less positive than that an unmodified carbon paste electrode (CPE). The catalytic oxidation peak current was linearly dependent on the D ‐PA concentration and a linear calibration curve was obtained in the ranges 7.5×10^?5 M – 1.0×10^?3 M and 6.5×10^?6 M?1.0×10^?4 M of D ‐PA with cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods respectively. The detection limits (3σ) were determined as 6.04×10^?5 M and 6.15×10^?6 M. This method was also used for the determination of D ‐PA in pharmaceutical preparation (capsules) by standard addition method.     

延胡索酸泰妙菌素在碳糊电极上的电化学性质及电分析方法

运用循环伏安法(CV)、计时电流法(CA)和计时电量法(CC)研究了延胡索酸泰妙菌素(Tiamulin fumarate,TF)在碳糊电极(Carbon Paste Electrode,CPE)上的电化学及其电化学动力学性质。结果表明,TF在CPE上的电化学过程是一不可逆的氧化过程,氧化峰电位Ep为0.772 V。在扫描速度10～1 000 mV.s-1范围内,其氧化峰电流Ip与扫描速度v呈良好的线性关系,表明TF在CPE上的伏安行为是一受吸附控制的过程。方波伏安(SWV)法结果表明TF氧化峰电流与其浓度在5.0×10-7～1.0×10-5mol.L-1及1.0×10-5～1.0×10-4mol.L-1范围内均呈良好的线性关系,相关系数r分别为0.9980及0.9966,检出限(S/N=3)为5.8×10-8mol.L-1,相对标准偏差(RSD)为0.8%～2.8%,加样回收率为97.6%～102.0%。据此建立了TF含量的电化学测定方法。该方法简便快捷,测定结果令人满意。     

A Novel Sensitive Electrochemical Sensor Based on Nickel Chloride Solution Modified Glassy Carbon Electrode for Curcumin Determination

In this research, the high conductivity of nickel chloride solution as well as the ability of nickel ions in establishing particular bonds with curcumin was benefited to fabricate a new electrochemical sensor based on nickel chloride solution modified glassy carbon electrode (NiCl₂/GCE) for detection and measurement of curcumin in human blood serum. Atomic force microscope (AFM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) methods indicated that using nickel chloride solution for the modification of the glassy carbon electrode (GCE) surface had a significant effect on improvement of the electrode performance. Differential pulse voltammetry (DPV) was used for quantitative measurement of curcumin, which exhibited the linear response of NiCl₂/GCE toward curcumin within the concentration range of 10–600 μM and provided the detection limit of 0.109 μM for curcumin in human blood serum.