聚L-白氨酸-碳纳米管修饰电极同时检测对苯二酚和邻苯二酚

用Nafion将单壁碳纳米管(SWCNT)固定到玻碳电极(GCE)上,再利用电化学聚合方法将L-白氨酸(L-LEU)聚合到SWCNT/GCE上,制备得到poly L-LEU/SWCNT/GCE修饰电极。采用循环伏安法(CV)、差分脉冲伏安法(DPV)和电化学交流阻抗法(EIS)研究了对苯二酚(HQ)、邻苯二酚(CC)共存时,二者在修饰电极上的电化学行为。结果表明:此修饰电极对HQ和CC有很好的电催化和分离作用。二者在修饰电极上的氧化还原峰电流与GCE相比显著增强,HQ和CC的氧化峰电位差和还原峰电位差分别为124 mV和131 mV。HQ和CC的检测线性范围分别为2.0×10-7~1.0×10-4、5.0×10-7~1.0×10-4mol/L。检出限分别为8.0×10-8、1.0×10-7mol/L。制备的修饰电极重现性、稳定性良好。在模拟废水中采用该修饰电极对HQ和CC进行检测,结果满意。     

聚氨基黑10B/Nafion修饰电极上多巴胺的检测

用电化学聚合法制备了聚氨基黑10B/Nafion修饰电极,利用循环伏安法研究了多巴胺在此修饰电极上的电化学行为.在磷酸盐缓冲溶液(pH 6.0)中,多巴胺在修饰电极上呈现可逆的氧化还原峰.其峰电位都随pH值的增加而负移.多巴胺氧化还原峰电流与其浓度在0.2～30 μmol/L范围内呈良好的线性关系;检出限为1.0×10~7 mol/L.实验结果表明:本修饰电极具有良好的重现性、稳定性和较强的抗干扰能力.将此修饰电极用于多巴胺注射液和小牛血清中多巴胺的检测,结果令人满意.     

电聚合硫菫膜修饰电极同时测定儿茶酚和氢醌

制备了电聚合硫堇膜修饰的玻碳电极(Thi/GCE),研究了儿茶酚(CC)和氢醌(HQ)在该修饰电极上的电化学行为.在CC和HQ共存体系中,二者在该修饰电极上与裸玻碳电极(GCE)相比,氧化峰电流增大且峰电位分别负移至165、68 mV,二者的氧化峰电位差变大且半峰宽变窄,使得两峰得以有效分离.据此利用差分脉冲伏安法可选...     

多巴胺在牛磺酸修饰玻碳电极上的电化学行为及其分析应用

采用电化学聚合法制备了牛磺酸修饰玻碳电极,研究了多巴胺在聚牛磺酸修饰电极上的电化学行为,建立了测定痕量多巴胺的新方法.在pH 7.2的磷酸盐缓冲溶液中,多巴胺在修饰电极上产生一对灵敏的氧化还原峰,采用差分脉冲伏安法测定,其氧化峰电流与多巴胺浓度在8.0×10-8～1.0×10-4 mol/L范围内呈良好的线性关系,检出限为1.0×10-8 mol/L.     

聚吡咯薄膜中茜素红S的电化学特性

利用循环伏安法研究了聚合电位和聚合电量对茜素红S掺杂聚吡咯薄膜修饰玻碳电极性质的影响,考察了不同电位范围内修饰电极的电化学特性.发现在茜素红S的氧化还原过程中存在着茜素红S分子与聚吡咯链的相互作用,且这一相互作用敏感于扫描正电位限.基于实验结果,提出了可能的茜素红S在电极表面聚吡咯膜内的氧化还原机理.     

电化学还原氧化石墨烯/碳纳米管复合物修饰电极对尿酸的检测

研究了电化学还原氧化石墨烯(ErGO)及多壁碳纳米管(MWNTs)复合物修饰电极的制备及应用,建立了一种尿酸测定的电化学分析新方法。通过滴涂法将物理超声共混的氧化石墨烯(GO)和MWNTs复合物修饰于裸电极上,随后将GO进行电化学还原制得ErGO-MWNTs复合物修饰电极。实验发现,相比于单独的ErGO修饰电极或MWNTs修饰电极,ErGO-MWNTs修饰电极具有更好的电催化活性,这归因于二者的协同电催化作用。对该电极进行尿酸检测的实验条件和参数进行了优化。在优化条件下,电极的氧化峰电流与尿酸浓度在0.13~45μmol/L内呈现出良好的线性关系,相关系数为0.99681,检出限为50 nmol/L。     

蒽醌/聚吡咯复合膜修饰电极的电化学行为和电催化活性

在水溶液中制备了掺杂蒽醌磺酸盐(AQS)的聚吡咯(PPy)/玻碳复合膜修饰电极,采用循环伏安法和旋转圆盘电极技术研究了该修饰电极在不同pH值溶液中的电化学行为以及在pH=5.5的磷酸盐缓冲溶液中对氧还原反应的电催化性能和动力学.结果表明,与裸玻碳电极相比,PPy膜的存在不仅降低了AQS的反应电位和峰电位差,而且增大了其氧化还原反应的峰电流,H2AQ/HAQ-氧化还原对的电离常数为9.5.AQS/PPy膜修饰电极上氧的还原主要是两电子还原为H2O2的不可逆过程,H2AQ对氧还原反应起主要催化作用,还原过程符合异相氧化还原催化机理.该修饰电极具有良好的电化学重现性.     

聚叶酸修饰电极的制备及其对肾上腺素的电催化氧化研究

采用电化学聚合的方法,将叶酸(FA)聚合在碳糊电极(CPE)表面,制备了聚叶酸修饰碳糊电极(PFA/CPE),并研究了肾上腺素(EP)在该修饰电极上的电化学行为。实验结果显示:在pH 7.0的磷酸盐缓冲溶液中,该聚合膜对EP的氧化有显著的催化作用,EP在修饰电极上产生2个氧化峰和一个还原峰,峰电位分别为0.193V、0.4184V和-0.252V。在测定实验条件下,EP在PFA/CPE上的氧化峰电流与其浓度在2.50×10-7～1.78×10-4mol/L范围内具有良好的线性关系,检出限可达1×10-7mol/L。将该电极应用于EP实际样品的测定,效果良好。     

电化学还原的氧化石墨烯修饰电极检测L-色氨酸

制备了氧化石墨烯修饰玻碳电极,并运用循环伏安法对氧化石墨烯进行了直接的电化学还原,研究了L-色氨酸在该电化学还原的氧化石墨烯修饰玻碳电极上的电化学行为。结果表明,L-色氨酸在该修饰电极上其氧化峰电流与裸玻碳电极相比增大了7.1倍,且峰电位负移80mV。利用差分脉冲伏安法,在pH=6.5的磷酸盐缓冲溶液中测定L-色氨酸,氧化峰电流与其浓度在0.4～65.0μmol/L范围内呈良好的线性关系,相关系数为0.998,方法检出限为0.2μmol/L。     

聚灿烂甲酚蓝膜修饰电极测定抗坏血酸的研究

电化学聚合制备了聚灿烂甲酚蓝薄膜修饰玻碳电极,研究了修饰电极对抗坏血酸的电催化氧化作用。结果表明二步法电聚合制备的修饰电极性能优于一步法电聚合,在该电极上抗坏血酸的过电位降低320mV,催化氧化峰电流与抗坏血酸的浓度在2×10-5～5×10-3mol/L范围内呈良好的线性关系,相关系数0.9982。方法可用于药品及食品中抗坏血酸的分析。     

Electrochemical preparation of composite of poly brilliant cresyl blue (PBCB)–poly 5-amino-2-napthalenesulfonic acid electrode and electrocatalytic application

Poly brilliant cresyl blue (PBCB) and poly 5-amino-2-napthalenesulfonic (PANS) polymer composite modified electrode was fabricated by the electrochemical polymerization of brilliant cresyl blue and 5-amino-2-napthalenesulfonic acid. When compared polymer composite electrodes with PBCB and PANS electrode, it showed enhanced electrochemical property. The morphology of the resulting composite electrode was characterized by AFM, and the electrochemical properties of the modified electrode were characterized by cyclic voltammetry and amperometry. The composite electrode showed surface-confined and pH-dependent electrochemical property. The composite electrode exhibited high catalytic behavior toward the reduction of hydrogen peroxide at low overpotential. The detection limit and sensitivity of the electrode toward H₂O₂ detection was 5 μM and 1 μA/mM, respectively, and response time was less than 10 s for hydrogen peroxide.     

聚苯胺薄膜修饰电极对抗坏血酸的电催化氧化

本文表明聚苯胺(PAn)薄膜修饰电极对水溶液中的抗坏血酸(AH_2)在较宽的pH范围和较宽的浓度范围内均有良好的电催化氧化作用, 为EC平行催化过程。利用旋转圆盘电极(RDE)进行了催化过程动力学分析, 求出了催化反应动力学参数。在抗坏血酸浓度10~(-2)～10~(-6) mol·L~(-1)范围内, 催化峰电流与AH_2浓度均成良好的线性关系, 且PAn薄膜修饰电极具有很好的稳定性, 有应用分析抗坏血酸的意义。     

Poly(3,4-ethylenedioxythiophene-co-(5-amino-2-naphthalenesulfonic acid)) (PEDOT-PANS) film modified glassy carbon electrode for selective detection of dopamine in the presence of ascorbic acid and uric acid

Poly(3,4-ethylenedioxythiophene-co-(5-amino-2-naphthalenesulfonic acid)) (PEDOT-PANS) film modified glassy carbon electrode was prepared by electrochemical polymerization technique. The properties of modified electrode was studied. It was found that the electrochemical properties of modified electrode was very much dependent on the experimental conditions, such as monomer oxidation potential and pH. The modified electrode surface was characterized by scanning electron microscopy (SEM). The PEDOT-PANS film modified electrode shows electrocatalytic activity toward oxidation of dopamine (DA) in acetate buffer solution (pH 5.0) and results in a marked enhancement of the current response. The linear sweep voltammetric (LSV) peak heights are linear with DA concentration from 2 × 10⁻⁶ to 1 × 10⁻⁵ M. The detection limit is 5 × 10⁻⁷ M. More over, the interferences of ascorbic acid (AA) and uric acid (UA) were effectively diminished. This work provides a simple and easy approach for selective determination of dopamine in the presence of ascorbic acid and uric acid.     

聚谷氨酸修饰电极测定盐酸异丙肾上腺素

盐酸异丙肾上腺素( Isoprenaline Hydrochloride)是β肾上腺素受体激动药,有舒张支气管、改善心肌传导和扩张周围血管作用.目前,测定异丙肾上腺素的方法有高效液相色谱法[1,2]、毛细管区带电泳法[3]、化学发光法[4]和激光散斑法[5]等.     

Poly(2,2′-(1,4-phenylenedivinylene) Bis-8-hydroxyquinaldine) Modified Glassy Carbon Electrode for the Simultaneous Determination of Paracetamol and p-Aminophenol

A novel assay is reported for the simultaneous determination of paracetamol and p-aminophenol using a poly(2,2′-(1,4-phenylenedivinylene)bis-8-hydroxyquinaldine) modified glassy carbon electrode. Poly(2,2′-(1,4-phenylenedivinylene)bis-8-hydroxyquinoline) modified electrodes were prepared by electrochemical polymerization. The electrode surface was characterized by scanning electron microscopy. The electrochemical behavior of the modified electrode was investigated by cyclic voltammetry, square wave voltammetry, and electrochemical impedance spectroscopy. The anodic peak potentials for paracetamol and p-aminophenol were at 580 and 337 millivolts, respectively, with a separation of 243 millivolts, adequate for their simultaneous determination. The results showed that the linear dynamic ranges for paracetamol and p-aminophenol were 0.5–200 micromolar and 3–150 micromolars, whereas the limits of detection were 0.075 and 0.45 micromolar, respectively. The novel poly(2,2′-(1,4-phenylenedivinylene)bis-8-hydroxyquinaldine) modified electrode provided excellent selectivity, sensitivity, and stability and was employed for the determination of paracetamol and p-aminophenol in pharmaceutical products and urine.     

聚苯胺纳米纤维修饰石墨箔电极的制备及电化学性能

以石墨箔(GF)为工作电极, 采用循环伏安法(CV), 通过电化学聚合, 制备了聚苯胺(PANI)纳米纤维修饰GF电极(Nano-PANI/GF). 利用红外光谱(FTIR)研究了Nano-PANI/GF修饰电极上聚合物的组成, 利用扫描电镜(SEM)观测了Nano-PANI/GF修饰电极的表面形貌. 利用循环伏安法研究了Nano-PANI/GF修饰电极在0.1 mol/L磷酸盐缓冲溶液(pH=6.9)中的电化学活性, 发现Nano-PANI/GF修饰电极在中性溶液中有良好的电化学活性. Nano-PANI/GF修饰电极对抗坏血酸(AA)电化学氧化的催化作用结果表明, 在0.2 V(vs. SCE)电位下, 在浓度范围1.7~2.0×10³ μmol/L内, 抗坏血酸的氧化电流与浓度呈良好线性关系, 线性方程式为y=0.00013x+0.0031. 修饰电极对抗坏血酸的最低检测限为1.7 μmol/L(S/N=3).     

Fabrication and characterization of poly 2-napthol orange film modified electrode and its application to selective detection of dopamine

The present work is based on the use of a redox mediator containing an azo group for the selective determination of dopamine in the presence of uric acid and ascorbic acid by electrochemical method. A modified electrode was prepared by electrochemical polymerization of the poly 2-napthol orange film (P2NO) on the paraffin wax-impregnated graphite electrode (PIGE) by applying potential between ?0.6 and 0.8 V at scan rate of 50 mV s^?1 for 30 segments. The modified P2NO film electrode was characterized by ATR-IR spectroscopy, FE-SEM, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), differential pulse voltammetry (DPV), hydrodynamic voltammetry (HDV), and chronoamperometry (CA). The P2NO film modified electrode exhibited selective determination of dopamine in the presence of uric acid and ascorbic acid, and the electrocatalytic activity for oxidation of dopamine was excellent. The linear range for the determination of dopamine was 0.6 to 250 μM with a limit of detection of 0.13 μM. The modified P2NO electrode showed good stability and reproducibility. The modified electrode was used for real sample analysis such as human blood serum, rat blood serum, and pharmaceutical samples (dopamine hydrochloride injection). The results obtained were found to be satisfactory.     

水介质中吡咯的电化学聚合反应

研究了扫描电位上限对循环伏安法制备聚吡咯膜性能的影响，吡咯在水溶液中于玻碳电极表面化学聚合的起始电位为0．58V，在聚吡咯（Ppy）修饰电极表面聚合的起始电位为0．55V，当聚合电位上限在0．80V以上时，Ppy的氧化还原反应可逆性变差，同时，氧化电位过高将导致Ppy膜导电性能下降；研究了聚合介质对循环伏安法制备导电聚吡咯膜的影响，实时观察了吡咯（Py）聚合过程溶液中质子含量的动态变化，发现Py聚合伴随有质掺杂←→释放过程；结合Ppy膜的元素分析、ESR分析和IR光谱分析，总结出了水介质中电化学聚合高导电性聚吡咯膜的条件。     

Electrochemical Properties of Lanthanum Hexacyanoferrate Particles Immobilized onto Electrode Surface by Au‐Codeposition Method

Lanthanum hexacyanoferrate (LaHCF) was immobilized onto a substrate surface as an electroactive material by Au‐codeposition method. The LaHCF particles were attached to the electrode surface as the result of occlusion within the gold film deposited. This deposition method was first introduced for the preparation of hexacyanoferrate‐based modified electrodes. It was demonstrated that this deposition method provides a higher stability of the electroactive film in comparison with available methods for the mechanical attachment of electroactive films. On the other hand, electrochemical properties of the LaHCF film modified electrode were studied for the first time. The results showed that LaHCF film has excellent electrochemical activity as well as other analogues of Prussian blue. The modified electrode was successfully used as an electrocatalyst for the oxidation of ascorbic acid.     

三乙醇胺对聚邻苯二胺pH敏感电极性能的影响

在含有邻苯二胺和三乙醇胺(TEA)的酸性溶液中,用循环伏安法(CV)在铂电极上制备聚邻苯二胺(PoPD)薄膜.通过对该薄膜进行深入的电化学分析,并将结果与无三乙醇胺参与的聚邻苯二胺的性能进行比较,发现在三乙醇胺参与下得到的聚邻苯二胺薄膜在铂电极表现出更好的粘附性,同时在氢离子选择性电极方面表现出优良的性能.在pH 2～13范围内具有良好的Nernst响应,直线斜率为59.62 mV/pH,相关系数达0.99以上,碱性条件下响应时间可缩短至30 s左右.该电极对大多数普通干扰物具有较好的选择性,可用于实际样品的测试.