以Nafion修饰的镀铂玻碳电极为基底的半乳糖传感器的制备

在镀铂的玻碳电极表面,修饰一层全氟代磺酸酯(Nafion)膜,制成基底电极。用化学交联法将半乳糖氧化酶(GAD)固定在基底电极表面,即制成半乳糖传感器。和光亮铂相比,镀铂电极对过氧化氢有更高的响应,而Nafion膜可以消除抗坏血酸,尿酸等电活性物质对测定的影响,提高了酶电极测定的选择性。D-半乳糖测定的线性范围为0.25～4.25 mmol/L,响应时间小于30s。电极连续使用300次,没有明显的电流变化。该电极具有快速、准确,选择性高的特点。     

基于电化学聚合技术的分子印迹化学传感器研究进展

作为传感器中最重要的研究方向之一,分子印迹传感器在近十年的发展中取得了巨大进展。分子印迹聚合物膜在转换器表面的固定化方法有涂膜法、原位引发聚合法和电化学聚合法等,其中电聚合法因具有制备简单快速、膜厚可控、膜与电极附着紧密、重现性好等优点而成为极具潜力的制备方法。该文评述了基于电化学聚合技术的分子印迹传感器的主要研究进展,对聚合膜制备过程中单体的选择和模板的去除进行了讨论,对电聚合制备的印迹传感器在传感领域的分析应用进行了总结,并在此基础上对其未来发展进行了展望。     

鲁米诺在氧化铟锡玻璃上的电聚合及电化学发光性能研究

研究了鲁米诺在氧化铟锡(Indium-tinoxide,ITO)玻璃上的电聚合。通过循环伏安和紫外吸收光谱表征,在酸性条件下可以实现鲁米诺对ITO电极的电聚合修饰,聚合在ITO玻璃表面的鲁米诺保持其良好的电化学发光性能,考察了此修饰电极的性能以及相关因素对聚合膜的电化学发光强度的影响。     

含噻吩的共聚物有序薄膜的制备及电性能测试

通过自组装技术(SAM)在ITO基底表面化学吸附一层规整有序单分子膜,然后在催化剂存在下,通过表面引发Suzuki缩聚反应制备得到有序的聚合物薄膜,并研究了聚合条件对聚合物薄膜性能的影响。从SEM和AFM对聚合物薄膜的形貌表征结果可知,聚合物薄膜已经顺利制备于ITO玻璃表面,并且以化学键与ITO表面垂直相连。通过对不同聚合条件下聚合物薄膜的XRD测试,结果表明随着聚合时间的延长及聚合单体浓度的增加,聚合物薄膜的有序性增加。除此之外,还对聚合物薄膜进行了光电性能测试,循环伏安的测试结果表明,随着聚合时间的延长及聚合单体浓度的增加,所得聚合物薄膜的能隙也在不断增加。电流-电压(I-V)测试结果表明,聚合物薄膜的电流随着电压的增大而增大,呈线性趋势,表明聚合物薄膜与ITO是欧姆接触,有利于电荷在电极的收集。     

金表面聚合物刷及图案化微结构的制备

采用表面引发室温原子转移自由基聚合(ATRP)方法在金基底上原位制备了接枝聚合物刷,其制备过程用厚度测量,ATR-FTIR,XPS等进行了表征,初始时聚合物刷的厚度随着聚合时间的增加线性增加,表现为活性聚合的特征．XPS表征证明表面引发聚合后聚合物刷末端仍然存在ATRP反应的引发剂．紫外光刻图案化的聚合物刷作为电沉积的模板,经电沉积、后紫外处理、湿化学刻蚀步骤后得到了分离的导电聚合物微阵列结构,通过浇注／粘附处理将导电聚合物微阵列转移至硅油弹性体片,由于导电聚合物在湿化学刻蚀中对基底金具有良好的保护作用,因此在导电聚合物阵列被转移后,基底表面得到金微阵列。     

一氧化氮在聚钴-席夫碱修饰电极上的电催化氧化

研究了一种新合成的杂环席夫碱Ｎ,Ｎ’－二乙酰吡啶缩双苯胺在铂电极上的电化学聚合、聚合膜与钴（Ⅱ）的配合反应及聚合物膜的电化学性质。实验结果表明,该席夫碱可在电极表面通过电化学聚合反应形成具有良好的机械、化学和电化学稳定性的聚合物膜,该聚合物膜可与钴离子形成稳定的配合物,这种配合物对和分子一氧化氮的电化学氧化有显著的催化作用。     

扫描电化学显微镜直接电沉积法构建葡萄糖氧化酶微米点

利用自制的凹形电极在铂基底电极上直接构建了葡萄糖氧化酶微米点. 首先, 将电聚合和电化学刻蚀法相结合制备了凹形铂微米电极. 然后将此种电极作为参比及辅助电极, 基底铂电极作为工作电极, 利用葡萄糖氧化酶在合适的条件下(浓度、一定量Triton X-100存在、电极电位等)由于电极表面pH的降低可以在铂电极上电沉积这一特性, 将酶固定在铂基底电极上, 微修饰得到了具有活性的葡萄糖氧化酶微米点. 最终用扫描电子显微镜和扫描电化学显微镜对所得微米点进行了表征. 所得微米点直径约20 μm, 且具有催化活性. 该方法简便, 干扰因素较少.     

以乙基紫为电活性物质的PVC膜碘离子电极的研制

对于不同活动载体的碘离子选择电极的研制与应用,国内外已有报道。如王彦等用水溶液沉淀法制备电活性物质,G．A．rechnitz等报道了AgI——硅橡胶膜电极等。上述电极在敏感膜的制备中多采用水溶液沉淀法或有机溶剂多次萃取的方法来制备电活性物质,操作较繁。本文报道直接以乙基紫为电活性物质制备PVC膜,然后在碘离子标准溶液中转型活化,获得了性能较佳的碘离子电极。     

化学修饰电极的研究 Ⅶ.电化学聚合法制备和研究乙烯二茂铁聚合物薄膜电极

聚合物薄膜电极具有电活性物的表面浓度高,稳定性好等优点,对电催化和电分析研究具有实际意义,是目前化学修饰电极发展的主要趋势。我们曾用电化学聚合法制备了二茂铁的羟基和酰基衍生物聚合物薄膜电极。本文用电化学聚合法-循环伏安(CV)法和恒电位氧化法研究了乙烯二茂铁(VFc)的聚合条件,分别以乙腈和乙醇为溶剂制备了VFc的聚合物(PVFc)薄膜电极,探讨了聚合反应机理。实验部分试剂:均为分析纯,水为二次蒸馏水。     

环取代基对金属化聚苯胺衍生物膜修饰电极性能的影响

通过比较聚2，5－二甲氧基苯胺（PDMAn）、聚邻甲基苯胺（POT）和聚间氯苯胺（PmClAn）膜修饰电极的氧化还原电位、沉积在这3种聚合物上的铂微粒的表面形态与晶面取向以及异丙醇在分散Pt微粒的聚苯胺膜修饰电极上的氧化行为，从电子效应和立体效应探讨了聚合物电化学性质与环取代基的关系以及不同聚合基质对Pt沉积机理和有催化性能的影响,结果表明，在硫酸溶液中PDMAn膜修饰电极的氧化还原电位最负、POT次之、PmClAn最正，Pt在PDMAn和POT膜上的电沉积机理与在PmClAn膜上的不同，聚合物膜上沉积的Pt微粒呈现（200)晶面择优取向，其中POT膜上择优取向度最大，PDMAn次之，Pm-ClAn最小，异丙醇在金属化聚合物膜电极上的氧化电位取决于聚苯胺的本质，在POT膜修饰电极上异丙醇的电氧化主要发生在POT的活性电位区，而在PDMAn与PmClAn膜上的电氧化则主要发生在Pt上的氧化电位区，说明聚合物膜不仅作为Pt微粒的分散介质，而且本身有产生催化作用。     

Fabrication of Photoelectrochemical Glucose Biosensor in Flow Injection Analysis System Using ZnS/CdS‐Carbon Nanotube Nanocomposite Electrode

In this work, a photoamperometric glucose biosensor based on glucose oxidase (GODx) was developed in flow injection analysis (FIA) system using ZnS‐CdS quantum dot (QD) modified multiwalled carbon nanotube/glassy carbon electrode (ZnS‐CdS/MWCNT/GCE). Cyclic voltammograms of the proposed electrode (GODx/ZnS‐CdS/MWCNT/GCE) showed a pair of well‐defined reversible redox peak attributing that direct electron transfer between the protein and electrode. The current of the reduction peak became more cathodic in the presence of O₂ due to the electrocatalytic activity of the electrode towards the reduction of dissolved O₂, but reduction current shifted to a less negative value upon addition of glucose in the solution. The obtained CV currents were affected by the irradiation of the electrode surface. Thus, the photoelectrochemical biosensing of glucose in the FIA system was studied by monitoring of the changes in the electrocatalyzed reduction peak current of dissolved O₂ at the proposed electrode dependent on glucose concentration. The proposed photoelectrochemical FIA method has a linear response to glucose ranging from of 0.01 to 1.0 mM with detection limit of 3.0 μM under optimized conditions. Photoelectrochemical biosensor was successfully fabricated in FIA system for selective, sensitive and repeatable detection of glucose and has been satisfactorily applied to determination of glucose in real sample.     

碳纳米管负载铂-二氧化钌纳米颗粒用于葡萄糖传感器的研究

建立了多壁碳纳米管(MWNTs)负载铂二二氧化钌纳米颗粒的液相化学还原法.以Nafion为固定剂,将Pt-RuO2/MWNTs复合材料修饰于玻碳电极的表面,制备了一种无酶型葡萄糖传感器.实验表明:复合材料修饰的电极对葡萄糖响应电流明显,并且受抗坏血酸(AA)、多巴胺(DA)和尿酸(UA)的干扰小.本实验采用安培法测定葡萄糖,线性范围为2 0×10 3～1.0×10-2 mol/L(R～0.9965);灵敏度为119.26 μA cm-2(mmol/L)-1;检出限为1.25×10 -5 mol/L(信噪比为3);响应时间为4.8 s.PtRuO2/MWNTs修饰电极可作为性能良好的无酶型葡萄糖传感器.     

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。     

A Facile Chemical Synthesis of Cu2O Nanocubes Covered with Co3O4 Nanohexagons for the Sensitive Detection of Glucose

Copper (I) oxide nanocubes (Cu₂O NCs) covered with cobalt oxide nanohexagons (Co₃O₄ NHs) were prepared through simple chemical method. Here, ascorbic acid is used as reducing and capping agent for the synthesis of nanocubes and nanohexagons. Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Energy‐dispersive X‐ray spectroscopy (EDX) and X‐ray diffraction spectroscopy (XRD) were employed to confirm the prepared nanocomposite. Cu₂O NCs?Co₃O₄ NHs nanocomposite is drop cast on the glassy carbon electrode (GCE) for the fabrication of glucose sensor. The fabricated Cu₂O NCs?Co₃O₄ NHs/GCE exhibited a better electrocatalytic activity towards the determination of glucose than that of individually fabricated Cu₂O NCs and Co₃O₄ NHs modified GCE. Our finding exhibited a wide linear range from 1 μM to 5330 μM with LOD of 0.63 towards glucose. In addition, the sensor attained appreciable stability, repeatability and reproducibility. Practicality of the sensor was demonstrated in human serum samples. The main advantages of the fabricated sensor are simple, biocompatible, cost effective, fast response and highly stable electrode surface.     

MWCNTs/Ionic Liquid/Graphene Quantum Dots Nanocomposite Coated with Nickel‐Cobalt Bimetallic Catalyst as a Highly Selective Non‐enzymatic Sensor for Determination of Glucose

In this work, a glassy carbon electrode (GCE) was modified with multiwall carbon nanotubes/ionic liquid/graphene quantum dots (MWCNTs/IL/GQDs) nanocomposite. Then, the nanocomposite was decorated with nickel‐cobalt nanoparticles (Ni?Co NPs), and it was used as a non‐enzymatic glucose sensor. Field emission scanning electron microscopy, X‐ray diffraction spectroscopy, and energy dispersive spectroscopy were employed to prove the electrodeposition of the Ni?Co NPs on the surface of MWCNTs/IL/GQDs/GCE. Also, cyclic voltammetric and amperometric methods were utilized for the investigation of the electrochemical behaviour of the Ni?Co NPs/MWCNTs/IL/GQDs/GCE for glucose oxidation. The novel amperometric sensor displayed two linear ranges from 1.0 to 190.0 μmol L^?1 and 190.0 to 4910 μmol L^?1 with a low detection limit of 0.3 μmol L^?1 as well as fast response time (2 s) and high stability. Also, the sensor showed good selectivity for glucose determination in the presence of ascorbic acid, citric acid, dopamine, uric acid, fructose, and sucrose, as potential interference species. Finally, the performance of the proposed sensor was investigated for the glucose determination in real samples. Ni?Co NPs/MWCNTs/IL/GQDs/GCE showed good sensitivity and excellent selectivity.     

Amperometric nonenzymatic determination of glucose based on a glassy carbon electrode modified with nickel(II) oxides and graphene

We have developed a stable and sensitive nonenzymatic glucose sensor by modifying a glassy carbon electrode (GCE) with a composite incorporating nickel(II) oxides and reduced graphene. The oxides were generated by directly electrodepositing nickel on the GCE with a graphene modifier using a multi-potential pulse process, and then oxidizing nickel to nickel(II) oxides by potential cycling. In comparison to the conventional nickel(II) oxides-modified GCE, this new nickel(II) oxides-graphene modified GCE (NiO-GR/GCE) has an about 1.5 times larger current response toward the nonenzymatic oxidation of glucose in alkaline media. The response to glucose is linear in the 20 μM to 4.5 mM concentration range. The limit of detection is 5 μM (at a S/N of 3), and the response time is very short (<3 s). Other beneficial features include selectivity, reproducibility and stability. A comparison was performed on the determination of glucose in commercial red wines by high-performance liquid chromatography (HPLC) and revealed the promising aspects of this sensor with respect to the determination of glucose in real samples.

Electrosynthesis of poly-o-diaminobenzene on the Prussian Blue modified electrodes for improvement of hydrogen peroxide transducer characteristics.

Electropolymerisation of nonconducting polymer, poly-(1,2-diaminobenzene) on the top of Prussian Blue (PB) modified electrode led to significant improvement of resulting hydrogen peroxide transducer selectivity and operational stability. The reported transducer retained 100% of response during 20 h under the continuous flow of 0.1 mM H(2)O(2), and thus improves the stability level in selective peroxide detection by one order of magnitude. The selectivity value of the PB-poly(1,2-DAB) based H(2)O(2) sensor in relation to ascorbate is approximately 600. No signals to acetaminophen and urate were investigated. PB-poly(1,2-diaminobenzene) modified electrode allows the detection of H(2)O(2) in the flow-injection mode down to 10(-7) M with the sensitivity 0.3 A M(-1) cm(-2), which is only two times lower compared to the uncovered PB based transducer.     

Nonenzymatic sensor for glucose based on a glassy carbon electrode modified with Ni(OH)2 nanoparticles grown on a film of molybdenum sulfide

A glassy carbon electrode (GCE) was modified with nickel(II) hydroxide nanoparticles and a film of molybdenum sulfide. The nanocomposite was prepared by two-step electrodeposition. Scanning electron microscopy reveals that the nanoparticles are uniformly deposited on the film. Cyclic voltammetry and chronoamperometry indicate that this modified GCE displays a remarkable electrocatalytic activity towards nonenzymatic oxidation of glucose. Response is linear in the 10–1,300 μM concentration range (R ² ?=?0.9987), the detection limit is very low (5.8 μM), response is rapid (< 2 s), and selectivity over ascorbic acid, dopamine, uric acid, fructose and galactose is very good.

Uracil Grafted Carbon Electrode:Electrocatalytic Behavior of Tryptophan,Tyrosine, Catecholamine and Related Compounds

基于尿嘧啶作为一种碱基,具备一定的分子识别能力,制备了一种新颖的尿嘧啶共价修饰电极,用X射线光电子能谱和电化学方法进行了表征,并研究了酪氨酸、色氨酸、儿茶酚胺（如多巴胺,肾上腺素,去甲肾上腺素）及相关的化合物尿酸、抗坏血酸在该电极上的电化学行为,获得相应的氧化电位、电流灵敏度、线性范围和检测限等信息。其中,色氨酸检测线性范围：1.8 - 120 mM,检测限（s/n=3）：0.8 mM;酪氨酸检测线性范围：1.8 - 89mM,检测限（s/n=3）：0.8 mM。实验表明,尿嘧啶修饰电极能催化氧化上述电活性物质,但催化能力不同,据此,我们讨论了尿嘧啶与上述物质的相互作用,详细探讨了催化机理,扩展了对基于分子识别的传感器的研究。     

Nanocellulose/Carbon Nanoparticles Nanocomposite Film Modified Electrode for Durable and Sensitive Electrochemical Determination of Metoclopramide

A novel electrochemical sensor based on nanocellulose‐carbon nanoparticles (NC‐CNPs) nanocomposite film modified glassy carbon electrode (GCE) is developed for the analysis of metoclopramide (MCP). Atomic force microscopy, scanning electron microscopy and electrochemical impedance spectroscopy were used to characterize the roughness, surface morphology and performance of the deposited modifier film on GCE. SEM image demonstrated that modifier nanoparticles are uniformly deposited on GCE, with an average size of less than 50 nm. The electrochemical behavior of MCP and its oxidation product is studied using linear sweep and cyclic voltammetry over a wide pH range on NC‐CNPs modified glassy carbon electrode. The results revealed that the oxidation of MCP is an irreversible and pH‐dependent process that proceeds in an adsorption‐controlled mechanism and results in the formation of a main oxidation product, which adsorbs on the surface of NC‐CNPs/ GCE. The modified electrode showed a distinctive anodic response towards MCP with a considerable enhancement (49 fold) compared to the bare GCE. Under the optimized conditions, the modified electrode exhibited a wide linear dynamic range of 0.06–2.00 µM with a detection limit of 6 nM for the voltammetric determination of MCP. The prepared modified electrode showed several advantages such as simple preparation method, high stability, reproducibility, and repetitive usability. The modified electrode is successfully applied for the accurate determination of trace amounts of MCP in pharmaceutical and clinical preparations.