基于硫堇/碳纳米管修饰电极的新型过氧化氢电化学传感器

基于碳纳米管(CNTs)和硫堇(Th)的协同效应,将辣根过氧化物酶(HRP)通过戊二醛(GA)交联作用固定在硫堇(Th)/CNTs修饰电极上,构造了一种新型酶电极(HRP/GA-Th/CNTs/GC)。CNTs静电吸附正电荷的Th,而Th不仅可以促进电极和酶的氧化还原活性中心之间的电子传递,而且能使CNTs氨基(—NH2)功能化,从而利于HRP的固定。基于HRP/GA-Th/CNTs/GC电极的过氧化氢传感器具有较好的传感性能,且检出限低(0.3μmol.L-1)、响应时间短(5 s内)、抗干扰能力强。     

一种基于碳纳米管的安培型过氧化氢生物传感器

利用硫堇(th ion ine,Th i)作为介体结合多壁碳纳米管(MWNTs)、壳聚糖(ch itosan,CH IT)、辣根过氧化酶(HRP)的混合包埋物制作过氧化氢(H2O2)生物传感器。研究结果表明所得传感器对H2O2具有明显的增敏效应,线性范围为0.03~5.5 mmol/L,相关系数为0.9995;检出限为19μmol/L(S/N=3),具有良好的稳定性及工作寿命。     

甲氧苄啶修饰玻碳电极安培法对过氧化氢的测定

在0.1 mol·L~(-1) KNO_3底液中,研究了甲氧苄啶在玻碳电极上的电化学性质,发现在0.140、0.177 V处出现1对可逆的氧化还原峰.进一步用电化学沉积的方法将甲氧苄啶修饰在玻碳电极上,考察了各种实验条件对修饰电极性能的影响,并通过电子扫描显微镜和电化学阻抗谱对修饰电极的表面性质进行了表征,所制得的修饰电极对过氧化氢的还原有很好的催化作用.在-0.3 V的工作电位下,用计时安培法对过氧化氢进行了测定,过氧化氢的浓度在1.96×10~(-5) ～1.10×10~(-3) mol·L~(-1)范围内与响应电流呈线性关系,检出限为4.0 μmol·L~(-1).该修饰电极制作简单、使用寿命长,实际试样的回收率为97% ～104%.     

Prussian Blue Modified Submicron Structured Gold Electrodes for Amperometric Hydrogen Peroxide Sensing

In this work, we present a simple and effective approach for fabricating sub‐micron structured gold (SM−Au) electrodes by chemically etching the magnetron co‐sputtered gold film in KI solution for certain time. Such electrodes with a large surface area to volume ratio were used as the matrix for electrochemical deposition of Prussian blue (PB) to develop an electrochemical hydrogen peroxide sensor. Experimental characterization using scanning electron microscope and atomic force microscope shows that the thickness of PB layer on SM−Au electrode is around 140 nm, and is composited with cubic PB nanocrystals. The electrochemical performance of the designed sensor, studied using cyclic voltammograms and chronoamperometry methods, suggests that the sensor based on SM−Au/PB electrode presents the direct electron transfer of PB particle towards SM−Au film, and exhibits fast response, wide linearity, low detection limit and high stability. Under the optimized conditions, the sensitivity of the developed sensor for the detection of H₂O₂ reaches the value of 512 mA cm⁻² M⁻¹ with a linear range from 1 μM to 4.5 mM.     

普鲁士蓝-多壁碳纳米管复合材料修饰电极测定过氧化氢

利用电化学方法在多壁碳纳米管(MWCNT)修饰的玻碳电极表面聚合一层普鲁士蓝(PB)(PB/MWCNT/GCE),制备了一种新型的过氧化氢(H2O2)传感器。研究了该传感器对H2O2的电催化作用。讨论了支持电解质种类、酸度、修饰层厚度、电位和扫速等对H2O2响应的影响。研究表明,该传感器在以1.0mol/L KCl为支持电解质的磷酸盐溶液(pH=2.0)中,对H2O2具有明显的催化效应,测定的线性范围变宽,在2.9×10-6~8.8×10-2mol/L范围内还原峰电流与H2O2的浓度呈良好的线性关系,相关系数为0.9949;检出限为1.4×10-6mol/L。该电极用于医用消毒水中H2O2的测定,结果令人满意。     

A Novel Hydrogen Peroxide Biosensor Based on Adsorption of Horseradish Peroxidase onto a Nanobiomaterial Composite Modified Glassy Carbon Electrode

In this work, a novel hydrogen peroxide biosensor derived from maize tassel (MT) and multiwalled carbon nanotube (MWCNT) composite was used to adsorb horseradish peroxidase (HRP) onto the surface of a glassy carbon electrode through electrostatic interactions. The morphology and structure of the products were characterized by SEM, FTIR and UV‐visible spectroscopy. The electrochemical and electrocatalytic performance of the HRP/MT‐MWCNT/GCE was studied using voltammetric and amperometric methods. The amperometric response of the biosensor varied linearly with concentration of H₂O₂ from 9 µM to 1 mM with detection limit of 4.0 µM (S/N=3). Furthermore, the biosensor exhibited good reproducibility and stability.     

基于硫堇/碳纳米管修饰金电极的过氧化氢生物传感器

制备了以硫堇(TH)、纳米金(Nano-Au)及多壁碳纳米管(MWNT)修饰的H2O2生物传感器.探讨了工作电位、温度、pH对电极响应的影响,考察了电极的重现性、抗干扰能力及使用寿命.该传感器具有线性范围宽、检出限低、灵敏度高、稳定性好和抗干扰能力强等特点.其线性范围为7.0×10-7～4.0×10-3 mol/L;检出限为2.3×10-7 mol/L;灵敏度为0.13 A/(mol L-1 cm2);达到稳定电流所用时间《9 s.米氏常数为0.62 mmol/L,表明所固定的酶具有较高的生物活性.     

Immobilization of Hemoglobin on the Gold Colloid Modified Pretreated Glassy Carbon Electrode for Preparing a Novel Hydrogen Peroxide Biosensor

A novel hydrogen peroxide (H₂O₂) biosensor was developed by immobilizing hemoglobin on the gold colloid modified electrochemical pretreated glassy carbon electrode (PGCE) via the bridging of an ethylenediamine monolayer. This biosensor was characterized by UV-vis reflection spectroscopy (UV-vis), electrochemical impendence spectroscopy (EIS) and cyclic voltammetry (CV). The immobilized Hb exhibited excellent electrocatalytic activity for hydrogen peroxide. The Michaelis–Menten constant (K _m) was 3.6 mM. The currents were proportional to the H₂O₂ concentration from 2.6 × 10⁻⁷ to 7.0 × 10⁻³ M, and the detection limit was as low as 1.0 × 10⁻⁷ M (S/N = 3).     

Amperometric Hydrogen Peroxide Biosensor Based on Horseradish Peroxidase Immobilized on Fe3O4/Chitosan Modified Glassy Carbon Electrode

A new type of amperometric hydrogen peroxide biosensor was constructed based on horseradish peroxidase (HRP) immobilized on Fe₃O₄/chitosan modified glassy carbon electrode. The effects of some experimental variables such as the concentration of supporting electrolyte, pH, enzyme loading, the concentration of the mediator of methylene blue (MB) and the applied potential were investigated. The linear range of the calibration curve for H₂O₂ was 2.0×10^?4–1.2×10^?2 M with a detection limit of 1.0×10^?4 M (S/N=3). The response time was less than 12 s. The apparent Michaelis‐Menten constant K_m was 21.4 mM and it illustrated the excellent biological activity of the fixed enzyme. In addition, the biosensor had long‐time stability and good reproducibility. And this method has been used to determine H₂O₂ concentration in the real sample.     

A New Amperometric Biosensor Based on HRP/Nano-Au/L-Cysteine/Poly（o-Aminobenzoic acid）-Membrane-Modified Platinum Electrode for the Determination of Hydrogen Peroxide

The third generation amperometric biosensor for the determination of hydrogen peroxide （H2O2） has been described. For the fabrication of biosensor, o-aminobenzoic acid （oABA） was first electropolymerized on the surface of platinum （Pt） electrode as an electrostatic repulsion layer to reject interferences. Horseradish peroxidase （HRP） absorbed by nano-scaled particulate gold （nano-Au） was immobilized on the electrode modified with polymerized o-aminobenzoic acid （poABA） with L-cysteine as a linker to prepare a biosensor for the detection of H2O2. Amperometric detection of H2O2 was realized at a potential of ＋20 mV versus SCE. The resulting biosensor exhibited fast response, excellent reproducibility and sensibility, expanded linear range and low interferences. Temperature and pH dependence and stability of the sensor were investigated. The optimal sensor gave a linear response in the range of 2.99×10^-6 to 3.55×10^-3 mol·L^-1 to H2O2 with a sensibility of 0.0177 A·L^-1·mol^-1 and a detection limit （S/N = 3） of 4.3×10^-7 mol·L^-1. The biosensor demonstrated a 95% response within less than 10 s.     

A Hydrogen Peroxide Biosensor Combined HRP Doped Polypyrrole with Ferrocene Modified Sol-gel Derived Composite Carbon Electrode

Conducting polymers, because of bearing many attractive features, for example, shuttling electrons between the electrode surface and the entrapped reagents (enzymes, mediators, etc.) while preventing interference and electrode fouling, have been proposed as enzyme supports for electrochemical biosensors1-4. Polypyrrole, owing to its popularity to water solubility and the mild conditions used for electropolymerization, has been the most widely used monomer to entrap enzymes5-8. The sol-gel prog…     

Methylene Blue/Multiwall Carbon Nanotube Modified Electrode for the Amperometric Determination of Hydrogen Peroxide

A novel amperometric sensor based on the incorporation of multiwalled carbon nanotubes (MWCNT) into a poly(methylene blue) (PMB) film immobilized on carbon composite electrodes is described. Cyclic voltammetry indicated that at a surface covered by a MWCNT/PMB layer the cathodic reduction of hydrogen peroxide is facilitated and occurs already at 0.0 V versus SCE. The effect of the order of deposition of PMB and MWCNT, as well as its loading, on electrochemical behaviour was evaluated by cyclic voltammetry and electrochemical impedance spectroscopy. The influence of the various immobilised platforms on the electrocatalytic performance towards hydrogen peroxide was also examined.     

Amperometric Determination of Hydrogen Peroxide and its Mathematical Simulation for Horseradish Peroxidase Immobilized on a Sonogel Carbon Electrode

A mathematical model of a horseradish peroxidase biosensor was applied to simulate the amperometric response for the detection of hydrogen peroxide. The development of the mathematical model was based on the Michaelis–Menten equation and Fick’s Second Law. The theoretical study is based on the determination of physico-chemical and geometric parameters of a horseradish peroxidase biosensor as well as the kinetic parameters of reaction mechanism such as diffusion coefficients of hydrogen peroxide, the thickness of enzymatic layer, and the Michaelis–Menten kinetic constant. The theoretical analysis provides an accurate estimate of parameters affecting the biosensor performance such as the diffusion coefficient of hydrogen peroxide in the biomembrane that was estimated to be 56?×?10^?12 m²/s. The thickness of diffusion layer was estimated to be 80–100?µm and the biomembrane 7.5?µm. The experimental and numerical values of kinetic parameters were 0.92 and 0.98?µM for the Michaelis–Menten constants and 0.010 and 0.012?µM/s for the catalytic activity rates. The model was validated for hydrogen peroxide detection and exhibited a good agreement with the experimental measurements.     

纳米金修饰玻碳电极固载抗体电位型白喉类毒素免疫传感器的研究

将巯基乙胺 (AET)固载到玻碳电极 (GCE)表面 ,进而化学吸附纳米金 (NG) ,并通过半胱氨酸 (Cys)用戊二醛 (GA)作交联剂将白喉抗体 (anti Diph)固定在玻碳电极上 ,从而制得高灵敏电位型白喉类毒素 (Diph)免疫传感器 .通过循环伏安法考察了电极表面的电化学特性 ,并对该免疫传感器的性能进行了详细的研究 .该传感器对白喉类毒素检测的线性范围是 2 4～ 60 0ng·mL-1,斜率为 3 8.9mV/decade ,线性相关系数为 0 .9979,检出限为 5 .2ng·mL-1,并将其用于生物制品中白喉类毒素的检测 ,其结果令人满意     

聚合物纳米组装体修饰丝网印刷电极构建过氧化氢传感器

通过在聚合物结构中同时引入生物亲和单体和电活性单体,使得聚合物组装体在修饰丝网印刷电极时兼具提高比表面积、保持酶活和促进电子转移功能,从而发展了一种简单、高效构建电化学传感器的方法。 以苯乙烯(St)、丙烯酸(AA)、N-乙烯基咔唑(VCz)和甲基丙烯酸二甲氨基乙酯(DMAEMA)为单体自由基聚合合成双亲性无规共聚物Poly(St-co-AA-co-VCz-co-DMAEMA)(PSACD),将聚合物在选择性混合溶剂DMF/H₂O中自组装得到聚合物纳米粒子PSACD NPs。 利用纳米粒度分析仪、扫描电子显微镜(SEM)对其进行表征。 依次将PSACD NPs水分散液、辣根过氧化物酶(HRP)溶液和全氟磺酸-聚四氟乙烯共聚物(Nafion,NF)溶液滴涂在丝网印刷碳电极(SPCE)上,制备得到过氧化氢生物传感器。 通过计时电流法对传感器性能进行研究,表明该传感器对H₂O₂在0.02~7.48 mmol/L有良好的线性响应,且响应时间短(<2 s),具有良好的选择性和稳定性。     

基于纳米金和硫堇固定酶的过氧化氢生物传感器

在铂电极上自组装一层纳米金(GNs), 构建负电荷的界面, 然后通过金-硫、金-氮共价键合作用和静电吸附作用自组装一层阳离子电子媒介体硫堇(Thio). 再以同样的作用自组装一层GNs和辣根过氧化酶(HRP)的混合物, 最后在电极最外层滴加一层疏水性聚合物壳聚糖(Chit), 由此制备了一种新型的过氧化氢生物传感器. 研究了工作电位、检测底液pH、温度对响应电流的影响, 以及GNs和HRP之间的相互作用, 探讨了传感器的表面形态、交流阻抗、重现性和稳定性. 该传感器的酶催化反应活化能为12.4 kJ/mol, 表观米氏常数为6.5×10^－4 mo/L, 在优化的实验条件下, 所研制的传感器对H₂O₂的线性范围为5.6×10^－5～2.6×10^－3 mol/L, 检出限为1.5×10^－5 mol/L. 应用此方法制备了HRP和葡萄糖氧化酶(GOD)双酶体系葡萄糖生物传感器, 并应用于实验样品葡萄糖含量的测定.     

Sensitive Electrochemical Determination of Hydrogen Peroxide Using Copper Nanoparticles in a Polyaniline Film on a Glassy Carbon Electrode

Rapid and accurate determination of hydrogen peroxide is necessary in biochemistry and environmental science. In this paper, a sensitive hydrogen peroxide electrochemical sensor was developed by cyclic voltammetry deposition of polyaniline–copper nanocomposite film on a glassy carbon electrode. The synthesized polyaniline/Cu composites were characterized by scanning electron microscopy and X-ray diffraction. With a typical working potential of 0.4?V (versus Ag/AgCl) and a pH value of 6.0, the prepared electrochemical sensor achieved linear range of 1.0–500?µM for hydrogen peroxide detection. A relative standard deviation of 4.9% for n?=?7 and 10.0?µM of H₂O₂ and a limit of detection of 0.33?µM at a signal-to-noise ratio?=?3 were observed. The sensor was successfully used for the analysis of tap water, and a spiked recovery of 93.0?±?2.1% was obtained, further confirming the sensor’s accuracy and feasibility.     

多壁碳纳米管修饰玻碳电极用于过氧化氢的检测

构建用于过氧化氢检测的多壁碳纳米管修饰玻碳电极,循环伏安阳极最大电流法和计时安培电流法测试表明:碳纳米管能提高电极的有效表面积,并加速电子的传递.循环伏安阳极最大电流和计时安培响应电流均与过氧化氢的浓度变化成线性关系,两种检测方法的灵敏度和线性相关系数分别为2.8μA/(mmol.L-1)、0.997和1.5μA/(mmol.L-1)、0.971;检测方法过程简单,结果令人满意.