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1.
Electroanalytical methods can be used for the reliable detection of the toxic heavy metal lead in drinking water samples. Inkjet printed electrodes have potential for the rapid and affordable assessment of drinking water. Researchers have shown the electrochemical sensing applicability of inkjet printed electrodes. In this work, Pb2+ was detected using an inkjet printed multi‐walled carbon nanotube (IJP‐MW‐CNT) electrode with silver tracks printed underneath. The silver tracks provide the sensor with the conductivity needed for sensitive measurements. MW‐CNT were dispersed in water using bile salts as a surfactant to prepare the ink. The IJP‐MW‐CNT electrode was used as the working electrode with a platinum wire and Ag/AgCl as auxiliary and reference electrode, respectively. The electrodes performance was optimized in 0.1 M acetate buffer (pH=4.3) and had two linear ranges of 5 to 20 ppb (R2=0.99) with a sensitivity of 38 nA/ppb and 20 to 50 ppb (R2=0.98) with a sensitivity of 15 nA/ppb and a limit of detection (LOD) of 1.0 ppb for Pb2+. The analytical applicability of electrode was determined by constructing a calibration curve in an unaltered drinking water sample (i. e.) Cincinnati tap water with two linear ranges of 15 to 40 ppb (R2=0.99) with a sensitivity of 1.5 nA/ppb and 40 to 70 ppb (R2=0.99) with a sensitivity of 3.5 nA/ppb and a LOD of 1.0 ppb for Pb2+. Effects of copper and cadmium as potential interferents are reported.  相似文献   

2.
制备了金纳米粒子/碳纳米管修饰玻碳电极(AuNPs-CNTs/GCE),采用循环伏安法和线性扫描伏安法研究了4-壬基酚在修饰电极上的电化学行为,并建立了一种灵敏简便地检测4-壬基酚的电化学方法。优化了pH值、扫描速率、富集时间等测定参数,并计算出pH值与氧化峰电压、扫描速率与氧化峰电流之间的数量关系。在pH 10.0的BR缓冲溶液中,4-壬基酚在AuNPs-CNTs/GCE上出现灵敏的氧化峰,氧化电位为0.51 V。与裸玻碳电极(GCE)和单一碳纳米管修饰电极(CNTs/GCE)相比,AuNPs-CNTs/GCE明显提高了4-壬基酚的氧化电流。在优化实验条件下,4-壬基酚的浓度分别在0.05~4μmol/L和6~14μmol/L范围内与氧化峰电流呈良好的线性关系,检出限为0.023μmol/L,对于实际样品测定的回收率为95%~104%。该修饰电极具有良好的重现性和稳定性,可用于环境样品中4-壬基酚的直接检测。  相似文献   

3.
采用原位还原法制备金纳米粒子/聚多巴胺/碳纳米管(Au-PDA-MWNTs)复合材料,并将其用于建立高灵敏检测核黄素的电化学方法.采用紫外–可见光谱、扫描电镜、x-射线能谱对Au-PDA-MWNTs复合材料进行表征,采用循环伏安法和差示脉冲伏安法探讨核黄素(RF)在Au-PDA-MWNTs修饰的玻碳电极上的电化学行为,并对RF含量进行测定.该方法对核黄素的检测在5×10-9 mol·L-1~1×10-5 mol·L-1的范围内呈良好的线性关系(R=0.9906),检测限为1.7×10-9 mol·L-1.本方法操作简便、抗干扰能力强,方法可行,因此该方法成功实现了维生素药片中RF含量的测定.  相似文献   

4.
以表面处理多壁碳纳米管(MWCNTs)和硝酸银为原料,利用硼氢化钠还原法制备了纳米银/多壁碳纳米管复合材料(AgNPs/MWCNTs),并通过紫外-可见吸收光谱、红外光谱、拉曼光谱和X射线衍射进行表征。采用滴涂法将该纳米复合材料修饰至玻碳电极表面,得到纳米银/多壁碳纳米管修饰电极(AgNPs/MWCNTs/GCE)。以AgNPs/MWCNTs/GCE为工作电极,研究了缓冲溶液、pH值、支持电解质和扫描速度对磺胺甲■唑(SMZ)电化学反应活性的影响。结果表明,与多壁碳纳米管、纳米银单独修饰电极相比,该纳米复合材料修饰电极对SMZ显示了更高的电催化活性。优化条件下,SMZ浓度在3.0×10~(-7)~5.0×10~(-5) mol/L范围内与峰电流呈线性关系,检出限(S/N=3)为6.4×10~(-8) mol/L。该方法操作简单、快速,可用于河水样品中SMZ的检测。  相似文献   

5.
于浩  高小玲  徐娜  陈小霞  冯晓  金君 《分析测试学报》2016,35(11):1416-1421
采用过氧化氢刻蚀法制备石墨烯量子点(GQDs),再采用原位化学还原法制备金纳米粒子-石墨烯量子点纳米复合物(Au NPs-GQDs),最后以聚二甲基二烯丙基氯化铵(PDDA)为交联剂将上述纳米复合物组装于多壁碳纳米管表面,制得金纳米粒子-石墨烯量子点-PDDA-多壁碳纳米管复合材料(Au NPs-GQDsPDDA-MWCNTs)。通过荧光光谱法、紫外-可见吸收光谱法和透射电子显微镜对上述复合材料进行表征。采用滴涂法制得该复合材料修饰的玻碳电极,研究了过氧化氢在该电极上的电化学行为。结果表明:在石墨烯量子点、金纳米粒子和多壁碳纳米管三者的协同作用下,该电极对过氧化氢的电氧化表现出强的催化活性。在优化条件下,安培法检测H_2O_2的线性范围为2.0×10~(-8)~1.5×10~(-3)mol/L,检出限(3sb)为8.0×10~(-9)mol/L,灵敏度为61.6μA/(mmol·L~(-1))。  相似文献   

6.
《Electroanalysis》2004,16(20):1697-1703
An amperometric glucose biosensor based on multi‐walled carbon nanotube (MWCNT) modified glassy carbon electrode has been developed. MWCNT‐modified glassy carbon electrode was obtained by casting the electrode surface with multi‐walled carbon nanotube materials. Glucose oxidase was co‐immobilized on the MWCNT‐modified glassy carbon surface by electrochemical deposition of poly(o‐phenylenediamine) film. Enhanced catalytic electroreduction behavior of oxygen at MWCNT‐modified electrode surface was observed at a potential of ?0.40 V (vs. Ag|AgCl) in neutral medium. The steady‐state amperometric response to glucose was determined at a selected potential of ?0.30 V by means of the reduction of dissolved oxygen consumed by the enzymatic reaction. Common interferents such as ascorbic acid, 4‐acetamidophenol, and uric acid did not interfere in the glucose determination. The linear range for glucose determination extended to 2.0 mM and the detection limit was estimated to be about 0.03 mM.  相似文献   

7.
In this work, an electrochemical sensor based on pyrolytic graphite electrode (PGE), cobalt phthalocyanine (CoPc) and multiwalled carbon nanotube (MWCNT) composite designed as PGE‐MWCNT/CoPc was developed and validated for pyridoxine (vitamin B6) determination employing Differential Pulse Voltammetry (DPV). The electrochemical behaviour of pyridoxine at the PGE‐MWCNT/CoPc has been evaluated and the charge transfer coefficient, α, and the charge transfer rate constant, κ, were calculated as 0.30 and 11.67±0.43 s?1, respectively, which indicates that, although this system is irreversible, it is viable kinetically to be used as a sensor. The optimized experimental conditions were pH 5.5 in 0.30 mol L?1 phosphate buffer. The linear range found was 10 to 400 μmol L?1 of pyridoxine, with r=0.9987. The limits of detection and quantification were 0.50 and 1.67 μmol L?1, respectively, showing the good sensitivity of the method. The method was successfully applied for the pyridoxine determination in real samples of pharmaceutical formulation with RSD% lower than 5 % indicating that it can be used for routine quality control pharmaceutical formulations containing pyridoxine. Furthermore, it has the advantages of a fast response, a low detection limit and low cost.  相似文献   

8.
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%.  相似文献   

9.
以灭除威(XMC)为模板分子,甲基丙烯酸(MAA)为功能单体,合成的马来松香丙烯酸乙二醇酯(EGMRA)为交联剂,在石墨烯掺杂金纳米粒子修饰玻碳电极表面合成分子印迹膜,研制了测定XMC的分子印迹电化学传感器。采用扫描电镜(SEM)对传感膜的形貌进行表征,通过循环伏安法(CV)、电化学阻抗谱法(EIS)和差示脉冲伏安法(DPV)对传感器的性能进行研究。DPV测试表明,XMC的浓度在1.0×10-7~2.0×10-5mol·L-1范围内呈良好线性关系,相关系数(r)为0.997 9,检出限(S/N=3)为1.5×10-8mol·L-1。选择性识别实验结果表明,XMC印迹敏感膜的印迹因子(β)达到2.94,相对于干扰物的选择因子(α)均大于1,对与XMC结构相似的速灭威的选择因子达到2.39,说明该印迹膜对XMC具有良好的选择性。识别过程动力学研究结果表明,石墨烯掺杂金纳米粒子分子印迹传感器的动力学结合速率常数k为73.05 s。将此传感器应用于蔬菜样品的加标回收检测,加标回收率为95.4%~108.0%。  相似文献   

10.
A new carbon nanotubes modified electrode (poly‐Nq‐MWCNTs/GCE) was fabricated by electropolymerization of 1,2‐naphththoquinone to the surface of multi‐walled carbon nanotubes modified electrode by casting method. The morphology of the nanocomposite was characterized by scanning electron microscopy. Cyclic voltammetry and chronoamperometry were applied to investigate the electrochemical properties of the poly‐Nq‐MWCNTs nanocomposite modified electrode. The result of electrochemical experiments showed that such modified electrode had a favorable catalytic ability to oxidation of β‐nicotinamide adenine dinucleotide (NADH). The resulted sensor was sensitiveness to NADH and achieved 95β of the steady‐state current within 5s. Furthermore, the anodic peak current was linear to the concentration of NADH for the range from 1.0 μM to 0.14 mM. The linear equation was: I(μA) = 0.3987 + 0.1035c (μmol/L), the correlation coefficient r = 0.9962, the detect limit is down to 1 × 10?7 M (S/N = 3) and the sensitivity is 0.1035 μA/mmol. The well catalytic activity of the sensor was ascribed to the synergistic effect role played by MWCNTs and poly‐Nq. Moreover, the based sensor possesses good stability and reproducibility.  相似文献   

11.
《Analytical letters》2012,45(17):2813-2828
The goal of this study was to develop a suitable electroanalytical method for the determination of primary compounds in the extracts of capsaicin and silymarin. For this purpose, a glassy carbon electrode immobilized with multiwalled carbon nanotubes decorated with gold nanoparticles was characterized by high resolution transmission electron microscopy and attenuated total reflectance infrared spectroscopy. The developed electrochemical sensor had a linear dynamic range from 0.15 to 35.0 µM. In addition, the limits of quantification for silymarin and capsaicin with the gold nanoparticle decorated multiwalled carbon nanotubes were 0.1564 and 0.2761 µg L?1 with relative standard deviations (n = 3) of 1.65% and 2.09% and equivalent mass percentages of 93.33% and 62.02%, respectively. The methodology may be employed for the determination of capsaicin and silymarin in pharmaceutical and food products.  相似文献   

12.
采用循环伏安法在玻碳电极表面依次电沉积纳米二氧化锆和铂微粒,制备了一种检测甲醛的新型电化学传感器。用电镜扫描对该修饰电极表面进行了表征,循环伏安法和线性扫描伏安法研究了甲醛在该修饰电极上的电催化氧化作用,优化了实验参数。结果表明,该修饰电极对甲醛有很好的电催化氧化作用,在0.1 mol/L H2SO4溶液中,甲醛的氧化峰电流与其浓度在1.0×10-6~5.0×10-3mol/L范围内呈良好线性关系,回归方程为Ip(μA)=79.95+2.005×105c(mol/L),相关系数r=0.999 3,检出限为5.0×10-7mol/L。  相似文献   

13.
盐酸伪麻黄碱;碳纳米管修饰电极;电催化氧化;电化学动力学  相似文献   

14.
郑志祥  王玫  李江  宫雪  王春明 《分析测试学报》2019,38(10):1220-1227
利用表面具有丰富π电子的三聚氰胺(MAM)和单壁碳纳米管(SWCNTs)作为前驱体,通过固体研磨-热聚合法使二者通过π-π静电作用堆叠得到类石墨相氮化碳(Graphitic carbon nitride,g-C_3N_4)-SWCNTs复合材料,然后利用Na_2PdCl_4为Pd纳米粒子前体,通过自组装对g-C_3N_4-SWCNTs进行功能化修饰,得到Pd/g-C_3N_4-SWCNTs复合物。采用SEM、TEM、XRD、FTIR对该复合材料的形貌和组成进行表征,并利用循环伏安等电化学方法研究了该材料对雌二醇(E2)的电催化氧化性能。结果显示,雌二醇在Pd/g-C_3N_4-SWCNTs修饰电极上的响应电流明显大于其在g-C_3N_4、g-C_3N_4-SWCNTs修饰电极和裸玻碳电极上的响应。在优化实验条件下,采用示差脉冲伏安法考察了基质样品中E2的氧化峰电流与其浓度的关系,其氧化峰电流强度与其浓度在5~150μmol/L范围内呈良好的线性关系,线性方程为:I_(pa)(μA)=0.834 7+0.007 0C_(E2)(r=0.990),检出限(LOD,S/N=3)为1.7μmol/L。该传感器具有良好的稳定性和选择性,且与HPLC在方法学上无显著性差异,可满足饲料样品中E2的检测需求。  相似文献   

15.
In this work, a sensitive electrochemical DNA biosensor for the detection of sequence‐specific target DNA was reported. Firstly, CuO nanospindles (CuO NS) were immobilized on the surface of a glassy carbon electrode (GCE). Subsequently, gold nanoparticles (Au NPs) were introduced to the surface of CuO NS by the electrochemical deposition mode. Probe DNA with SH (HS‐DNA) at the 5′‐phosphate end was covalently immobilized on the surface of the Au NPs through Au? S bond. Scanning electron microscopy (SEM) was used to elucidate the morphology of the assembled film, and electrochemical impedance spectroscopy technique (EIS) was used to investigate the DNA sensor assembly process. Hybridization detection of DNA was performed with differential pulse voltammetry (DPV) and the methylene blue (MB) was hybridization indicator. Under the optimal conditions, the decline of reduction peak current of MB (ΔI) was linear with the logarithm of the concentration of complementary DNA from 1.0×10?13 to 1.0×10?6 mol·L?1 with a detection limit of 3.5×10?14 mol·L?1 (S/N=3). In addition, this DNA biosensor has good selectivity, and even can distinguish single‐mismatched target DNA.  相似文献   

16.
通过电聚合和电沉积方法首次制得聚(三聚氰胺)和金纳米粒共修饰的电极(PMel/Au/GCE),并对修饰电极进行交流阻抗电化学分析。采用循环伏安法研究了芦丁在修饰电极上的电化学行为,发现其氧化峰电流和还原峰电流较裸玻碳电极(GCE)以及聚(三聚氰胺)修饰的电极(PMel/GCE)明显增强,提高了检测的灵敏度。对溶液的pH值、金纳米粒子电沉积时间、三聚氰胺电聚合时间和扫描速率等实验条件进行了优化。采用示差脉冲伏安法对芦丁进行定量分析,芦丁浓度分别在7.8×10-9~1.2×10-6mol/L和1.2×10-6~1.5×10-5mol/L范围内与峰电流呈线性,其相关系数(r2)分别为0.997和0.993,检出限(S/N=3)为5.5×10-9mol/L。将该电极用于市售芦丁片检测,回收率为96.4%~101.8%。  相似文献   

17.
The electrocatalytic oxidation of rapamycin, one of the most studied immunosuppressant, cancer-preventing drug, is investigated for the first time on the surface of the modified carbon paste electrode prepared by incorporating multi-walled carbon nanotubes (MWCNTs) and conductive polymer pyrrole using differential pulse voltammetry (DPV). Rapamycin exhibited a well-defined oxidation peak at +1.1 V (versus Ag/AgCl) in Briton Robinson buffer solution with a pH 4.0. Effect of the most important experimental parameters was optimized and obtained signals are linear to the concentration of rapamycin in the range from 0.1 to 20 μM with 0.06 μM limit of detection. The repeatability is calculated as ±2 % and the reproducibility as ±5 %. The possible interfering compounds were tested showing negligible effect and the sensor was successfully applied for the determination of rapamycin in commercial pharmaceutical formulations with obtained recoveries in the range from 98 % to 102 %.  相似文献   

18.
Nanoporous materials have been widely applied to biosensor investigation. Recently, Guo et al. have investigated the mesoporous materials modified carbon paste electrode for rapid cTnI (cardiac troponin I) detection with enhanced sensitivity1-3. However, …  相似文献   

19.
Glassy carbon electrodes were modified with composites containing cobalt tetraaminophenoxy phthalocyanine nanoparticles (CoTAPhPc NP ), multi‐walled carbon nanotubes (MWCNT) and gold nanorods (AuNRs). The modified electrodes were studied for their electrocatalytic behavior towards the reduction of hydrogen peroxide. Phthalocyanine nanoparticles significantly improved electron transfer kinetics as compared to phthalocyanines which are not in the nanoparticle form when alone or in the presence of multiwalled carbon nanotubes (MWCNTs). CoTAPhPc NP ‐MWCNT‐GCE proved to be suitable for hydrogen peroxide detection with a catalytic rate constant of 3.45×103 M?1 s?1 and a detection limit of 1.61×10?7 M. Adsorption Gibbs free energy ΔGo was found to be ?19.22 kJ mol?1 for CoTAPhPc NP ‐MWCNT‐GCE.  相似文献   

20.
Direct‐methanol fuel cells are proton‐exchange fuel cell in which methanol is used as the fuel. The important advantage of these fuel cells is the simplicity of transport and storage of methanol. In this study, methanol fuel cell electrocatalysts including graphene quantum dots (GQDs), functionalized multi‐walled carbon nanotubes (f‐MWCNTs) and GQDs/f‐MWCNTs composite were synthesized. The structures of synthesized electrocatalysts were highlighted by scanning electron microscope (SEM), raman spectroscopy, UV–vis spectroscopy, fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS) and x‐ray diffraction (XRD) method. After that, the effective surface areas (ESA) of GQDs, f‐MWCNTs and GQDs/f‐MWCNTs were calculated. Finally, GQDs/f‐MWCNTs composite modified glassy carbon electrode (GQDs/f‐MWCNTs/GCE) showed highest current signals for methanol oxidation than those of comparable GQDs/GCE and f‐MWCNTs/GCE.  相似文献   

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