聚3,4-乙撑二氧噻吩/金复合电极的制备及其在多巴胺检测中的应用

在水溶液中,以对甲苯磺酸钠为支持电解质,在氧化铟锡导电玻璃上,采用电化学恒电位极化法制备聚3,4-乙撑二氧噻吩(PEDOT)修饰电极。通过电化学循环伏安法,在PEDOT电极上沉积金纳米颗粒(Au NPs),制得PEDOT/Au复合修饰电极,用于多巴胺(DA)的电化学检测。考察了PEDOT/Au复合修饰电极中Au NPs的沉积量对DA电化学检测响应的影响,同时研究了在干扰物质抗坏血酸(AA)和尿酸(UA)存在时,PEDOT/Au复合修饰电极对DA的检测。结果表明,在中性p H溶液中,利用PEDOT/Au复合修饰电极,采用差分脉冲伏安法检测DA的线性范围为5×10-6¹×10-4mol/L,最低检测限可达1×10-8mol/L,且能有效排除AA和UA的干扰,实现三者的同时检测。     

3,4-乙撑二氧噻吩的合成研究

通过3,4-二溴噻吩与甲醇钠反应合成了中间体3,4-二甲氧基噻吩,再将3,4-二甲氧基噻吩与乙二醇于甲苯中反应,得到标题化合物,总收率为45%.     

聚(3,4-乙撑二氧噻吩)/木质素磺酸核壳粒子的制备工艺优化

以过硫酸钠为氧化剂,在木质素磺酸(LS)水溶液中通过化学氧化法聚合3,4-乙撑二氧噻吩(PEDOT),制备聚(3,4-乙撑二氧噻吩)/木质素磺酸(PEDOT/LS)水分散液。研究了木质素磺酸用量、氧化剂添加量、p H值、固含量和反应温度对产物PEDOT/LS的粒径及导电性的影响。实验得出较佳的反应条件是:木质素磺酸与EDOT单体质量比为2.0~2.5:1,氧化剂与EDOT摩尔比为1.3:1,反应体系p H值约1.5,固含量在1.8%~2.5%,反应温度10~20℃。用PEDOT/LS配制得到的涂层,表面电阻小于108??sq?1,光滑透明且附着力达到二级,满足抗静电剂的要求。     

3,4-乙撑二氧噻吩的合成工艺研究进展

聚3,4-乙撑二氧噻吩具有导电率高、热稳定性好、成膜性好的特点。在光伏电池、抗静电与电磁屏蔽等领域具有良好的用途。由于传统的3,4-乙撑二氧噻吩单体合成过程繁杂,导致3,4-乙撑二氧噻吩单体收率低、价格昂贵,至今未得到良好应用。本文介绍了合成3,4-乙撑二氧噻吩单体的最新研究进展,着重讨论了以价廉易得的氯乙酸乙酯为原料,经亲核取代、酯缩合、烷基化、水解与脱羧合成3,4-乙撑二氧噻吩的新"五步法"合成路线。通过对3,4-乙撑二氧噻吩新"五步法"合成路线的分析,总结了各步最优合成方法与条件,为3,4-乙撑二氧噻吩研究开发提供了借鉴。     

CuY型分子筛催化合成3,4-乙撑二氧噻吩

以2,5-二羧酸-3,4-乙撑二氧噻吩为原料,首次采用CuY型分子筛作催化剂应用于3,4-乙撑二氧噻吩合成,反应温度有了明显降低,合成条件更温和,产品收率更高。通过实验探讨了催化剂、温度、溶剂等因素对反应的影响。结果表明:当采用CuY型分子筛为催化剂、二甲基亚砜为溶剂、反应温度为135℃时,收率最高。产品结构经1 H NMR、13C NMR、IR和元素分析进行了表征。     

3,4-乙撑二氧噻吩合成及其聚合物应用进展

3,4-乙撑二氧噻吩(EDOT)是导电聚合物——聚3,4-乙撑二氧噻吩(PEDOT)的单体。目前,国内EDOT的产量和品质等方面较国外有较大差距。因此,对EDOT的合成工艺进行深入研究有着重要的社会和经济效益。总结了EDOT的主要合成方法及其聚合物在防腐蚀涂层、超级电容器、钙钛矿太阳能电池、水凝胶等领域的应用与发展。     

用聚3,4-乙撑二氧噻吩对聚丙烯腈进行导电改性的研究

采用原位化学氧化聚合方法在聚丙烯腈纤维表面生成聚3,4-乙撑二氧噻吩,制备得到纤维表面均匀覆盖聚3,4-乙撑二氧噻吩的改性导电纤维,其电导率约为1×10-3S/cm。纤维表面与导电聚合物的相互作用改善了原纤维的耐热性能,并对其力学性能没有造成伤害。     

3,4-二氧乙基噻吩及其聚合物的制备与应用进展

聚(3,4-二氧乙基噻吩)(PEDOT)是目前发现的导电态最稳定的导电高分子之一,对聚PEDOT及其单体3,4-二氧乙基噻吩(EDOT)的制备方法进行了综述,并介绍了PEDOT在抗静电、电解电容器、有机光电材料和传感器领域的研究和应用。     

新方法合成3，4-乙撑二氧噻吩系列化合物

从2,3-二甲氧基-1,3-丁二烯衍生物出发,微波辐射下采用一锅法成功合成了一系列3,4-乙撑二氧噻吩类化合物.3,4-乙撑二氧噻吩类化合物的结构经13CNMR、1HNMR、IR和元素分析进行了表征.此外,本文讨论了原料的量、催化剂和溶剂对3,4-乙撑二氧噻吩(EDOT)收率的影响.     

微波辐射下一锅法合成3,4-乙撑二氧噻吩类化合物

首次从2,3-二甲氧基-1,3-丁二烯衍生物出发,微波辐射下采用一锅法成功合成了一系列3,4-乙撑二氧噻吩类化合物.实验表明,该法具有反应条件温和、收率高和操作简单的优点.3,4-乙撑二氧噻吩类化合物的结构经 ~1HNMR 、~13CNMR、IR和元素分析进行了表征.也讨论了原料的量、催化剂和溶剂对3,4-乙撑二氧噻吩(EDOT)收率的影响.     

聚（3，4-乙撑二氧噻吩）/樟脑磺酸复合材料的合成及其电化学性能

以樟脑磺酸(HCSA)为掺杂剂,FeCl3为氧化剂,通过化学氧化聚合合成了聚(3,4-乙撑二氧噻吩)/樟脑磺酸(PEDOT/HCSA)复合材料;采用FTIR和SEM对其结构和形貌进行了表征;探讨了掺杂剂与单体摩尔比、氧化剂用量和反应时间对产品导电性能的影响;分析了产品的电化学性能。结果表明,当n〔3,4-乙撑二氧噻吩(EDOT)〕:n(樟脑磺酸):n(氯化铁)=2:1:40,反应时间41 h时,复合材料具有良好的导电性能和电化学性能,电导率为10.4 S/cm,经150次充放电老化后比容量可保持在140 F/g左右,是一种潜在的超级电容器电极材料。     

Preparation and characterisation of poly(3,4-ethylenedioxythiophene) and poly(3,4-ethylenedioxythiophene)/poly(neutral red) modified carbon film electrodes, and application as sensors for hydrogen peroxide

Poly(3,4-ethylenedioxythiophene) (PEDOT) films have been prepared for the first time on carbon-film electrodes (CFE) in aqueous solution using electropolymerisation by potential cycling, potentiostatically and galavanostatically. Characterisation of the modified electrodes was done by cyclic voltammetry and electrochemical impedance spectroscopy and the stability of the polymer films was probed. The coated electrodes were tested for application as hydrogen peroxide sensors, by oxidation and reduction. A novel polymer film was also formed by modification of CFE by co-electropolymerisation of EDOT and the phenazine dye neutral red (NR) – (PEDOT/PNR) with a view to enhancing the properties for sensor applications. It was found that hydrogen peroxide reduction at the PEDOT/PNR coated electrodes could be carried out at a less negative potential, the sensor performance comparing very favourably with that of other polymer-modified electrodes reported in the literature.     

Poly(3,4-ethylenedioxythiophene)/Au-nanoparticles composite as electrode coating suitable for electrocatalytic oxidation

Composite materials consisting of poly(3,4-ethylenedioxythiophene) including Au nanoparticles, encapsulated by citrate anions, have been firmly deposited on an electrode surface through a simple method, taking advantage of the interaction between Au metal and thiophene polymeric backbone. A series of similar electrode coatings, also including different amounts of nanoparticles inside, has been characterised in terms of thickness and surface morphology, through different microscopic techniques. The electrocatalytic properties have been studied with respect to the oxidation of glucose in alkaline media, which is prevented from occurring on the pure organic material.     

Multiwall carbon nanotube supported poly(3,4-ethylenedioxythiophene)/manganese oxide nano-composite electrode for super-capacitors

MWCNT-PSS/PEDOT/MnO₂ nano-composite electrodes were fabricated by generating pseudo-capacitive poly(3,4-ethylenedioxythiophene) (PEDOT)/MnO₂ nano-structures on poly(styrene sulfonate) (PSS) dispersed multiwalled carbon nanotubes (MWCNTs). PSS dispersed MWCNTs (MWCNT-PSS) facilitated the growth of PEDOT and MnO₂ into nano-rods with large active surface area and good electrical conductivity. The ternary MWCNT-PSS/PEDOT/MnO₂ nano-composite electrode was studied for the application in super-capacitors, and exhibited excellent capacitive behavior between −0.2 V and 0.8 V (vs. saturated Ag/AgCl electrode) with high reversibility. Specific capacitance of the nano-composite electrode was found as high as 375 F g⁻¹. In contrast, specific capacitance of MWCNT-PSS/MnO₂ and MWCNT-PSS nano-composite electrodes is 175 F g⁻¹ and 15 F g⁻¹, respectively. Based on cyclic voltammetric studies and cycle-life tests, the MWCNT-PSS/PEDOT/MnO₂ nano-composite electrode gave a highly stable and reversible performance up to 2000 cycles. Our studies demonstrate that the synergistic combination of MWCNT-PSS, PEDOT and MnO₂ has advantages over the sum of the individual components.     

Electro-oxidation of chlorophenols on poly(3,4-ethylenedioxythiophene)-poly(styrene sulphonate) composite electrode

The electrochemical behaviour of chlorinated phenols on Pt/poly(3,4-ethylenedioxy)thiophene,LiClO₄ and on Pt/poly(3,4-ethylenedioxy)thiophene,poly(sodium-4-styrenesulphonate) electrodes has been investigated in phosphate buffer solution. Poly(sodium-4-styrenesulphonate) exerts remarkable effect against the electrode fouling induced by oxidation of chlorophenols, allowing us to record the relevant anodic response even after repeated potential cycles. Hypotheses about the role exerted by poly(sodium 4-styrenesulphonate) are made, on the basis of evidences provided by several techniques, such as cyclic voltammetry, electrochemical impedance spectroscopy, electrochemical microgravimetry and atomic force microscopy. Thanks to the fact that different chlorophenols show differences in the voltammetric responses, depending on number and position of the chloro substituents on the aromatic ring, applications of the modified electrode in the analysis of mixtures of chlorinated phenols are possible.     

Development and characterisation of a novel composite electrode material consisting of poly(3,4-ethylenedioxythiophene) including Au nanoparticles

Composite material consisting of poly(3,4-ethylenedioxythiophene) (PEDOT), including Au nanoparticles encapsulated by N-dodecyl-N,N-dimethyl-3-ammonium-1-propanesulphonate (SB12) is synthesised by constant-current method on ITO glass, in aqueous medium, leading to an electrode coating. The synthesis process is followed by UV-vis spectroelectrochemistry, both in normal-beam and in parallel-beam configurations. Under the same experimental conditions PEDOT is also synthesised by electropolymerisation only in the presence of LiClO₄ supporting electrolyte, as well in solutions also containing SB12. The data relative to the electrosynthesis of the three materials are compared. The composite material based on the conductive polymer matrix including Au nanoparticles has been characterised by SEM, TEM, ICP, Raman and UV-vis spectroscopies. The behaviour of the three different electrode coatings with respect to p-doping process has been studied by conventional electrochemical techniques and by potentiostatic and potentiodynamic UV-vis spectroelectrochemical methods. Conclusions are drawn out about the effect of the presence of the surfactant and of Au nanoparticles on the electrochemical properties of the electrode system.     

Selective detection of dopamine on poly(indole-5-carboxylic acid)/tyrosinase electrode

We report here on a simple tyrosinase (TYR) modified electrode designed through the covalent bonding of the enzyme with poly (indole-5-carboxylic acid) (PIn5COOH) conducting polymer. This electrode was applied to the amperometric detection of dopamine (DA) in the presence of ascorbic acid (AA), uric acid (UA) and their mixtures, in the concentration range and ratios similar to those found in blood serum. Our experiments demonstrate that the presence of these interferents (AA, UA) does not affect the selectivity of such electrode towards dopamine with linear concentration dependence in the range of 0.5–20 μM, depending on the experimental conditions, however its sensitivity depends on the type and amount of interferent present. The lower limit of detection of DA in the presence of high AA (1000 fold) or UA (500 fold) concentration was found to be 0.1–0.5 μM. The sensitivity for DA detection is 6.2 A/M cm² with UA and 2.3 A/M cm² with AA present as interfering agents. For both interferents present in the ratio 12.5:1 (AA:UA), the sensitivity drops to the value of ca. 1.3 A/M cm². The Michaelis–Menten (K_M) constant and I_max values were evaluated, showing improved electrode sensitivity towards dopamine as judged from the decrease of the Michaelis–Menten constant.     

Enhanced thermoelectric properties of poly(3,4-ethylenedioxythiophene): Poly(styrenesulfonate)/copper phthalocyanine disulfonic acid composite films

A series of poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate)/copper phthalocyanine disulfonic acid (PEDOT: PSS/CuPc-[SO₃H]₂) composite films were prepared by using CuPc-(SO₃H)₂ as the dopant. EG treatment was applied to further improve the thermoelectric properties of PEDOT: PSS/CuPc-(SO₃H)₂ composites. Structural analyses indicated the strong π − π interactions existed between PEDOT: PSS and CuPc-(SO₃H)₂, and led to more ordered regions in the composite films, and benefit the conductivity. CuPc-(SO₃H)₂ can greatly improve the thermoelectric properties of PEDOT: PSS/CuPc-(SO₃H)₂ composite films, which have a Seebeck coefficient of 13.2 μV K⁻¹ and a conductivity of 2.8 × 10⁵ S/m with 20 wt% CuPc-(SO₃H)₂ at room temperature, and the corresponding power factor is 48.8 μW m⁻¹ K⁻², which is almost 6.83 times higher than the PEDOT: PSS films without CuPc-(SO₃H)₂.     

One-pot synthesis of poly(3,4-ethylenedioxythiophene)-Pt nanoparticle composite and its application to electrochemical H2O2 sensor

ABSTRACT: Poly(3,4-ethylenedioxythiophene)-Pt nanoparticle composite was synthesized in one-pot fashion using a photo-assisted chemical method, and its electrocatalytic properties toward hydrogen peroxide (H2O2) was investigated. Under UV irradiation, the rates of the oxidative polymerization of EDOT monomer along with the reduction of Pt4+ ions were accelerated. In addition, the morphology of PtNPs was also greatly influenced by the UV irradiation; the size of PtNPs was reduced under UV irradiation, which can be attributed to the faster nucleation rate. The immobilized PtNPs showed excellent electrocatalytic activities towards the electroreduction of hydrogen peroxide. The resultant amperometric sensor showed enhanced sensitivity for the detection of H2O2 as compared to that without PtNPs, i.e., only with a layer of PEDOT. Amperometric determination of H2O2 at 0.55 V gave a limit of detection of 1.6 uM (S N = 3) and a sensitivity of 19.29 mA cm2 M1 up to 6 mM, with a response time (steady state, t95) of 30 to 40 s. Energy dispersive X-ray analysis, transmission electron microscopic image, cyclic voltammetry (CV), and scanning electron microscopic images were utilized to characterize the modified electrode. Sensing properties of the modified electrode were studied both by CV and amperometric analysis.