分步电沉积普鲁士蓝、纳米铜复合膜修饰玻碳电极测定芦丁

采用分步电沉积方法,依次将普鲁士蓝膜(PB)和纳米铜(CuNPs)电沉积在玻碳电极(GCE)表面,制备了相应的修饰电极(CuNPs/PB/GCE)。考察了实验条件,并采用循环伏安(CV)法和差分脉冲伏安(DPV)法研究了芦丁在CuNPs/PB/GCE上的电化学行为,求解了相关的电化学参数。最佳条件下,采用DPV法,芦丁的还原峰电流与其浓度在1.0×10-8~1.0×10-4 mol/L范围内呈现良好的线性关系,其检出限(S/N=3)为2.8×10-9 mol/L。结果表明,电极表面PB和CuNPs的存在有效提高了芦丁的电化学响应。该修饰电极的选择性和重现性好,可以应用于水样中芦丁的检测。     

L-半胱氨酸/普鲁士蓝复合修饰玻碳电极的制备及电化学性能

通过电聚合方法和脉冲沉积技术将普鲁士蓝(PB)与L-半胱氨酸(L-Cys)修饰在玻碳电极(GCE)表面,制得复合膜化学修饰电极(L-Cys/PB/GCE/CME),利用循环伏安法和计时安培法研究了对苯二酚在L-Cys/PB/GCE/CME上的电化学特征。结果表明,在0.1 mol/L PBS(pH 7.0)缓冲溶液中,L-Cys/PB/GCE/CME对对苯二酚的电化学氧化具有明显的催化作用,氧化峰电流相对于在裸玻碳电极上增加了5倍。在最佳实验条件下,对苯二酚浓度在0.18~120μmol/L范围内,修饰电极的电流响应与对苯二酚浓度呈线性关系,其相关系数为0.9962,检出限(S/N=3)为0.065μmol/L。本研究制备的对苯二酚传感器具有较好的重复性、重现性、选择性与稳定性,用于实际水样中对苯二酚的测定,结果满意。     

纳米金-Nafion修饰金电极电化学阻抗法测定人端粒DNA

报道了基于纳米金-Nafion修饰金电极检测人端粒DNA的电化学阻抗传感器。将纳米金与Nafion混合超声得到纳米金-Nafion纳米材料,将此纳米材料滴涂于金电极表面获得纳米金-Nafion修饰电极。再将探针人端粒ss DNA滴涂在修饰电极上制备电化学阻抗传感器。利用扫描显微镜对纳米材料的形貌进行了表征。利用循环伏安法和电化学阻抗法对传感器进行了表征及目标人端粒DNA的定量测定。在最优化实验条件下,电化学阻抗传感器响应信号(ΔRet)与目标人端粒DNA浓度的对数(lgc)在0.001~1.0 nmol/L范围内呈良好线性关系。检出限为3.0 pmol/L。对0.5 nmol/L的目标人端粒DNA 7次平行测定,相对标准偏差RSD为3.5%。     

基于L-半胱氨酸/CdTe量子点修饰电极的电化学传感器的制备及其对Pb~(2+)的检测

成功制备了由L-半胱氨酸和CdTe量子点作为修饰材料的电化学传感器并用于水体中Pb~(2+)的检测。巯基丙酸修饰的CdTe量子点通过水相合成,表面含有大量羧基,与L-半胱氨酸表面的氨基形成酰胺键,修饰于金电极表面。通过荧光分光光度计、透射电子显微镜、红外光谱、X射线衍射对L-Cys/CdTe QDs复合材料进行表征。采用循环伏安法(CV)研究了L-Cys/CdTe QDs修饰成分在金电极上的电化学性能及CdTe量子点的最佳自组装时间。采用差分脉冲溶出伏安法(DPSV)研究了铅离子在修饰电极上的电化学行为。在优化实验条件下,Pb~(2+)浓度在1.0×10~(-6)~1.0×10~(-2) mol/L范围内与其峰电流呈良好的线性关系,相关系数(r2)为0.993 8,检出限(3σ,n=5)为4.0×10~(-7) mol/L。该传感器具有良好的重现性和稳定性,有望用于实际水样中铅离子的检测。     

普鲁士蓝包覆碳纳米管复合物修饰无酶过氧化氢传感器的研制及应用

本文通过在碳纳米管(MWNTs)表面原位自发还原形成普鲁士蓝纳米颗粒(PB),制备PB包覆的MWNTs纳米复合物(PB@MWNTs),并将其修饰于电极表面,直接催化过氧化氢,成功制得了一种无酶过氧化氢传感器。由于PB和MWNTs对过氧化氢都有较好的催化能力,使得制备的传感器具有好的性能。该传感器在H2O2浓度为1.8×10-7mol·L-1~4.2×10-3mol·L-1范围内,呈良好的线性,检测下限达到8.0×10-8mol·L-1(S/N=3),灵敏度为71.8A·L/mol/cm2。此外,传感器还表现出较好的稳定性、重现性和选择性     

基于立方体纳米氧化亚铜修饰的安培型葡萄糖生物传感器的制备及性能研究

将合成的立方体纳米氧化亚铜用于修饰玻碳电极,在其上固定葡萄糖氧化酶,构建了高灵敏的安培型葡萄糖生物传感器.采用X射线衍射(X RD)、扫描电镜(SEM)对合成的立方体纳米氧化亚铜及其修饰电极进行了表征.结果表明,合成的纳米氧化亚铜为均匀的立方体形状.采用循环伏安法(CV)、交流阻抗谱(EIS)、差分脉冲伏安法(DPV)及计时电流法(CA)考察了修饰电极的电化学行为.在含0.1 mmol/L葡萄糖的磷酸盐缓冲溶液(pH 7.4)中研究了立方体纳米氧化亚铜修饰电极的循环伏安(CV)响应,实验结果表明,此修饰电极对葡萄糖显示出良好的电催化性能.DPV响应电流与葡萄糖的浓度在5.0×10-6 ～4.0× 10-3mol/L范围内呈良好的线性关系,线性相关系数R2=0.9983,检出限为6.8×10-7 mol/L(S/N=3).CA实验结果表明,尿酸、抗坏血酸、D-果糖对传感器不产生干扰.本传感器具有较好的重现性和稳定性,可用于实际样品中葡萄糖的检测.     

聚脱氧腺苷酸/还原石墨烯纳米复合膜电化学传感器检测核黄素

以含32个碱基的聚脱氧腺苷酸(A32)作为黏合剂,将水合肼还原的石墨烯(RGO)固定在金(Au)电极表面,制备A32/RGO纳米复合膜电化学传感器.利用循环伏安法和交流阻抗法对传感器制备过程进行表征,并用循环伏安法和微分脉冲伏安法研究了该传感器的电化学行为.研究结果表明,与裸Au电极和A32修饰的Au电极相比,RGO/A32/Au电极对核黄素有较高的电化学活性,其还原峰电流与核黄素的浓度在0.025~2.75μmol/L范围内呈线性关系,检出限(S/N=3)为15 nmol/L.该传感器具有灵敏度高、抗干扰能力强及稳定性好等优点,可用于人尿中核黄素的分析测定.     

基于纳米金／壳聚糖掺杂碳纳米管修饰金电极非标记免疫传感器的研究

应用吸附法将羊抗人IgG抗体直接固定于纳米金(GNPs)/壳聚糖(Chit)掺杂碳纳米管(CNTs)修饰的金电极表面,制备了用于人IgG抗原检测的非标记电化学免疫传感器.利用循环伏安法和交流阻抗研究了修饰电极表面的电化学特性,用差分脉冲伏安法研究了测试底液的pH值对免疫传感器性能的影响.实验表明,在含不同浓度人IgG的...     

CuNPs/PAA/GR纳米新材料修饰玻碳电极检测猪肉中的莱克多巴胺

采用一种温和且简单的原位生长法将铜纳米粒子和石墨烯非共价键合,形成一种对莱克多巴胺催化活性高的复合纳米新材料Cu NPs/PAA/GR。该材料用扫描电镜表征形貌,用阻抗表征修饰电极。不同扫速和p H值条件下,以其修饰玻碳电极构建的电化学体系受吸附控制,莱克多巴胺在该电极表面的反应机理属两电子转移过程。体系中电化学参数为:电子转移数(n)=1.7,修饰电极的有效面积为3.57 cm2,为裸电极的12.6倍,电极吸附量(Гs)为1.98×10-12mol/cm2。采用微分脉冲伏安法进行检测,莱克多巴胺的浓度在1~30μmol/L范围内呈良好线性关系(r2=0.990 2),检出限(S/N=3)为18.3 nmol/L。该传感器经济易制备、灵敏性高、稳定性与重现性好。将该传感器用于猪肉中莱克多巴胺的检测,其回收率为97.0%~102.5%,相对标准偏差为2.8%~3.2%。     

还原石墨烯-碳纳米管-金纳米复合物的电化学发光过氧化氢传感器

以聚乙烯亚胺(PEI)为还原剂,采用一步还原法制备纳米金修饰的还原石墨烯-碳纳米管(AuNPs-rGO-CNTs)复合纳米材料。PEI同时作为交联试剂,使得AuNPs-rGO-CNTs复合物具有良好的成膜性质,能均匀的修饰到玻碳电极表面,制得AuNPs-rGO-CNTs修饰电极。基于过氧化氢(H2O2)作为鲁米诺-电化学发光(鲁米诺-ECL)体系的共反应试剂能显著增强鲁米诺的电化学发光信号,构建了AuNPs-rGO-CNTs复合物修饰的玻碳电极用于电化学发光测定H2O2的新方法。实验采用循环伏安法对传感器的修饰过程进行了表征。对测试底液中鲁米诺的浓度、pH等条件进行了优化,在最优实验条件下,该传感器的电化学发光信号强度与H2O2浓度在3.4×10-2~1.4×102μmol/L范围内呈良好的线性关系,检出限为1.1×10-2μmol/L。传感器适用于H2O2的测定。     

Functionalization of Single‐Walled Carbon Nanotubes with Cubic Prussian Blue and Its Application for Amperometric Sensing

In this work, we synthesized electroactive cubic Prussian blue (PB) modified single‐walled carbon nanotubes (SWNTs) nanocomposites using the mixture solution of ferric‐(III) chloride and potassium ferricyanide under ambient conditions. The successful fabrication of the PB‐SWNTs nanocomposites was confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV‐vis absorption spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and cyclic voltammetry (CV). PB nanocrystallites are observed to be finely attached on the SWNTs sidewalls in which the SWNTs not only act as a carrier of PB nanocrystallites but also as Fe(III)‐reducer. The electrochemical properties of PB‐SWNTs nanocomposites were also investigated. Using the electrodeposition technique, a thin film of PB‐SWNTs/chitosan nanocomposites was prepared onto glassy carbon electrode (GCE) for the construction of a H₂O₂ sensor. PB‐SWNTs/chitosan nanocomposites film shows enhanced electrocatalytic activity towards the reduction of H₂O₂ and the amperometric responses show a linear dependence on the concentration of H₂O₂ in a range of 0.5–27.5 mM and a low detection limit of 10 nM at the signal‐to‐noise ratio of 3. The time required to reach the 95% steady state response was less than 2 s. CV studies demonstrate that the modified electrode has outstanding stability. In addition, a glucose biosensor is further developed through the simple one‐step electrodeposition method. The observed wide concentration range, high stability and high reproducibility of the PB‐SWNTs/chitosan nanocomposites film make them promising for the reliable and durable detection of H₂O₂ and glucose.     

纳米银/石墨烯修饰电极测定青蒿素

本文建立一种新型的青蒿素传感器。首先,在玻碳电极上滴涂氧化石墨,通过电化学方法将氧化石墨还原为石墨烯,然后,在石墨烯上沉积纳米银得到石墨烯/纳米银修饰电极,它作为检测青蒿素的电化学传感器。用此电极对青蒿素进行测定,并通过循环伏安法、差分脉冲伏安法、交流阻抗法等研究其电化学行为。该修饰电极在测定青蒿素溶液时,表现出较正的还原电位和较大的峰电流等优势;对其实验条件如电解质溶液的p H、应用电势等进行了探查,该电化学传感器在青蒿素溶液浓度范围为1.0×10-8~3.0×10-5mol/L时与其还原峰电流呈现良好的线性关系,最低检出限为1.2×10-9mol/L(S/N=3)。此外,对该传感器的稳定性和重现性等也进行了研究,获得令人满意的结果。     

多贝斯在石墨烯修饰玻碳电极上的电化学行为及其测定

制备了石墨烯修饰玻碳电极（GN/GCE）。 在0.05 mol/L H2SO4溶液中,用循环伏安法研究了多贝斯在GN/GCE上的电化学行为。 结果表明,GN/GCE对多贝斯的氧化还原反应有明显的电催化作用。 建立了测定多贝斯的新方法,用微分脉冲伏安法测得多贝斯的氧化峰电流与其浓度在2.0×10-9~1.2×10-6 mol/L范围内呈线性关系,检出限为1.0×10-9 mol/L(S/N=3)。 该法可用于胶囊中多贝斯的测定,修饰电极有较好的稳定性和重新性。     

Electrochemical Fabrication of Prussian Blue Nanocube‐decorated Electroreduced Graphene Oxide for Amperometric Sensing of NADH

In this study, Prussian blue (PB) film on the electroreduced graphene oxide (ERGO)‐modified Au electrode surface (ERGO/PB) is easily prepared by means of cyclic voltammetric technique in the mixture of K₃Fe(CN)₆ and FeCl₃. Its electrochemical behaviors for NADH biosensor are studied. The structural and morphological characters of modified electrode material are analyzed with using of XPS, XRD, Raman, EDS, and SEM techniques. ERGO/PB hybrid nanocomposite for NADH biosensor is exhibited to the higher catalytic effect (linear range from 1.0 to 100 μM, detection limit of 0.23 μM at S/N=3) compared to naked Au, ERGO‐modified Au, and PB‐modified Au electrodes. In addition to, ERGO/PB electrode was used to voltammetric and amperometric detection of H₂O₂. ERGO/PB electrodes also showed the same behavior as the NADH sensor. This ERGO/PB‐modified electrode supplied a simple, new, and low‐cost route for amperometric sensing of both NADH and H₂O₂.     

A novel nitrite sensor based on graphene/polypyrrole/chitosan nanocomposite modified glassy carbon electrode

A novel nitrite sensor was fabricated based on a graphene/polypyrrole/chitosan nanocomposite film modified glassy carbon electrode. The nanocomposite film was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy. The electron transfer behaviour of the modified electrodes was investigated in [Fe(CN)(6)](3-)/(4-) redox probe using cyclic voltammetry and electrochemical impedance spectroscopy. Differential pulse voltammetry and amperometry were used to study the electrochemical properties of the proposed sensor. Under optimum conditions, the sensor exhibited good reproducibility and stability for nitrite determination. Linear response was obtained in the range of 0.5-722 μM with a detection limit of 0.1 μM (S/N = 3) for nitrite determination.     

New Nanocomposite Based on Prussian Blue Nanoparticles/Carbon Nanotubes/Chitosan and Its Application for Assembling of Amperometric Glucose Biosensor

Abstract

A new nanocomposite was developed by combination of prussian blue (PB) nanoparticles and multiwalled carbon nanotubes (MWNTs) in the matrix of biopolymer chitosan (CHIT). The PB and MWNTs had a synergistic electrocatalytic effect toward the reduction of hydrogen peroxide. The CHIT/MWNTs/PB nanocomposite‐modified glassy carbon (GC) electrode could amplify the reduction current of hydrogen peroxide by ～35 times compared with that of CHIT/MWNTs/GC electrode and reduce the response time from ～60 s for CHIT/PB/GC to 3 s. Besides, the CHIT/MWNTs/PB nanocomposite‐modified GC electrode could reduce hydrogen peroxide at a much lower applied potential and inhibit the responses of interferents such as ascorbic acid (AA) uric acid (UA) and acetaminophen (AC). With glucose oxidase (GOx) as an enzyme model, a new glucose biosensor was fabricated. The biosensor exhibited excellent sensitivity (the detection limit is down to 2.5 µM), fast response time (less than 5 s), wide linear range (from 4 µM to 2 mM), and good selection.     

Electrochemistry of Multilayers of Graphene and Myoglobin Modified Electrode and Its Biosensing

A multilayers of graphene (GR) and myoglobin (Mb) modified electrode was fabricated with a layer of chitosan film. Electrochemical behaviors of the modified electrode were studied by cyclic voltammetry, which exhibited a couple of well‐behaved, stable and quasi‐reversible cathodic and anodic peaks, indicating that Mb realized its direct electron transfer on the biosensor. The experimental result may be accredited to the existence of multilayers conductive GR nanosheets that could provide big specific surface area, fine biological compatibility and ultrahigh electron transfer route for the immobilized Mb. The catalytic reduction peak currents of the biosensor to the detection of trichloroacetic acid were established from 0.6 to 26.0 mM accompanied with the detection limit as 0.15 mM (3σ). Therefore a novel third‐generation mediator‐free electrochemical sensor was successful prepared with the usage of multilayers of GR.     

Electrochemical detection of DNA damage induced by in situ generated bisphenol A radicals through electro-oxidation

A glassy carbon electrode was modified with dsDNA and a nanocomposite composed of multi-walled carbon nanotubes and chitosan (MWNT-chit). The electrode was applied to the electrochemical detection of DNA damage as induced by in situ generated bisphenol A (BPA) radicals through electro-oxidation. The modified electrode was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The results indicate that MWNT-chit nanocomposite represents a viable platform for the immobilization of DNA that effectively promotes electron transfer between DNA and the electrode. The mode of interaction between DNA and BPA was investigated by differential pulse voltammetry and UV-vis spectrophotometry, indicating that the dominant interaction is intercalation. In order to explore the mechanism of damage caused by BPA radicals, the electro-oxidation of BPA at the modified glass electrode was investigated. Based on the signal for guanine without any other external indicator, DNA damage was investigated through the electro-oxidation of BPA.     

基于AuNPs/PANI/TNTs纳米复合材料的电化学检测妥布霉素的适配体传感器

本文提出了一种新型的检测妥布霉素的电化学适配体传感器,以差分脉冲伏安法（DPV）作为检测技术,亚甲基蓝作为电化学响应信号. 构建了以纳米复合材料金纳米粒子/聚苯胺/二氧化钛纳米管(AuNPs/PANI/TNTs)修饰玻碳电极的电极支架. 通过透射电子显微镜和X-射线光电子能谱对纳米复合材料进行详细的表征. 循环伏安图和电化学阻抗谱显示AuNPs/PANI/TNTs可以很好地增加电极的界面传导性能. DPV结果显示电流密度的响应和妥布霉素浓度之间存在一个很好的线性关系,并且得到一个宽广的检测范围为0.5 μmol·L^-1到70 μmol·L^-1. 本文提出的适配体基的传感器有很好的重复性和稳定性,作为一个潜在的手段可以应用在生物分析和医疗诊断中.     

三维有序石墨烯掺杂纳米二氧化钛酶生物传感器

采用模板法在氧化铟锡电极上制备了三维有序多孔结构的石墨烯掺杂纳米二氧化钛修饰电极,并在此修饰电极上成功固定了过氧化氢酶,从而构建了一种新型的H2O2生物传感器。 通过循环伏安、交流阻抗及计时电流等方法研究了该修饰电极的电化学特性,实验结果表明,该修饰电极对H2O2有良好的电催化作用,对H2O2的检测线性范围为3.0×10-6~3.6×10-3 mol/L,检测限为4.2×10-7 mol/L(S/N=3);且传感器响应迅速、灵敏度高、重现性和稳定性好。