电氧化异丙肾上腺素的纳米复合电催化剂:用作传感器（英文）

在金纳米粒子(AuNPs)上经苯硫酚衍生物(3,4二羟基苯基-偶氮-苯硫酚,DAT)自组装制得了一种新型纳米复合物,用于修饰玻璃碳电极(GCE/AuNP-DAT).采用循环伏安法研究了该新型电极的性质,并将其用作异丙肾上腺素(IP)电催化剂,考察了该纳米复合物的电催化活性,从而得到反应机理和催化反应速率常数.由于GCE/Au NP-DAT电极对尿酸氧化没有电催化活性,因此可将IP的氧化信号从该改进电极中分离出来,从而排除了尿酸对IP测定的干扰.该电极可作为传感器,当用于差动脉冲伏安法测定IP时,线性动态范围为1.0–1500.0μmol/L,检测极限为0.46μmol/L.     

碳纳米笼/碳纳米管复合物修饰电极制备及检测双酚A

通过水热反应合成羧基化碳纳米管(CNT-COOH)和碳纳米笼(CNCs)的纳米复合物(CNCs/CNT-COOH)。利用透射电子显微镜(TEM)、傅立叶红外光谱(FTIR)和热重分析(TGA)表征该复合材料。利用循环伏安法(CV)、差分脉冲伏安法(DPV)和交流阻抗法(EIS)研究CNCs/CNT-COOH/GCE修饰电极的电化学行为。结果表明,CNCs/CNT-COOH/GCE对双酚A的电化学氧化显示出优异的选择性和电催化活性。双酚A的氧化峰电流值与其浓度在2～200μmol/L范围内呈现良好的线性关系,经计算可得双酚A的检出限为0. 8524μmol/L (S/N=0. 0437),灵敏度为-0. 1539μA/(μmol/L)。将CNCs/CNT-COOH/GCE用于检测双酚A显示出灵敏度高、检测范围宽和稳定性良好的优点。     

电还原氧化石墨烯-金纳米棒修饰电极对酒石黄的测定

本文制备了氧化石墨烯-金纳米棒复合物(GO-GNRs).利用滴涂法制备了修饰电极(GO-GNRs/GCE),通过循环伏安法,还原了GO-GNRs复合物中的GO,制得电化学还原的石墨烯-金纳米棒修饰电极(ERGO-GNRs/GCE).研究了酒石黄在不同电极上的电流响应,结果表明,ERGO-GNRs/GCE对酒石黄的氧化有很好的电催化作用,其浓度在0.05～6.0μmol/L范围内与氧化峰电流呈良好的线性关系,检出限为15 nmol/L.利用ERGO-GNRs/GCE可完成样品中酒石黄含量的测定.     

纳米金/Nafion/石墨烯修饰玻碳电极检测对苯二酚的研究

采用一步电化学共还原的方法将纳米金(AuNPs)、Nafion、电化学还原石墨烯(ERGO)修饰到玻碳电极(GCE)表面,制成修饰电极AuNPs/Nafion/ERGO/GCE。以扫描电镜对其进行表征,用循环伏安法和微分脉冲伏安法研究对苯二酚在该修饰电极上的电催化行为。优化了实验参数,对苯二酚在2.0～100μmol/L及100～800μmol/L浓度范围内与其氧化峰电流呈良好的线性关系,检出限为0.3μmol/L。用该修饰电极成功地进行了实际水样中对苯二酚含量的测定。     

苯并噻唑和铁氧化物纳米粒子修饰的磁性棒碳糊电极上肼的电催化氧化反应：同时检测肼和苯酚

开发了一种磁性Fe3O4纳米粒子和2-(3,4-二羟苯基)苯并噻唑(DPB)修饰的磁性棒碳糊电极(MBCPE)用于电化学检测肼.首先将DPB自组装在Fe3O4纳米粒子上,然后将此复合物吸附于设计的MBCPE上. MBCPE电极将磁性纳米粒子吸引到电极表面.所得新型电极具有高的导电性和大的有效比表面积,因而对肼的电催化氧化反应有非常大的电流响应.采用伏安法、扫描电镜、电化学阻抗谱、红外光谱和紫外-可见光谱对修饰电极进行了表征.采用伏安法研究了在磷酸盐缓冲溶液(pH=7.0)中MBCPE/Fe3O4NPs/DPB电极上肼的电化学行为.作为电化学传感器, MBCPE/Fe3O4NPs/DPB电极对肼氧化反应表现出极高的电催化活性.在DPB存在下,肼的氧化电势下降,但其催化电流增加.电催化电流与肼浓度在0.1–0.4和0.7–12.0μmol/L二个区间内表现出线性关系,检测限为18.0 nmol/L.另外,研究了MBCPE/Fe3O4NPs/DPB电极同时检测肼和苯酚的性能.伏安实验结果显示,苯酚的线性区域为100–470μmol/L,检测限为24.3μmol/L.采用此电极检测了水样品中的肼和苯酚.     

苯并噻唑和铁氧化物纳米粒子修饰的磁性棒碳糊电极上肼的电催化氧化反应:同时检测肼和苯酚（英文）

开发了一种磁性Fe_3O_4纳米粒子和2-(3,4-二羟苯基)苯并噻唑(DPB)修饰的磁性棒碳糊电极(MBCPE)用于电化学检测肼.首先将DPB自组装在Fe_3O_4纳米粒子上,然后将此复合物吸附于设计的MBCPE上.MBCPE电极将磁性纳米粒子吸引到电极表面.所得新型电极具有高的导电性和大的有效比表面积,因而对肼的电催化氧化反应有非常大的电流响应.采用伏安法、扫描电镜、电化学阻抗谱、红外光谱和紫外-可见光谱对修饰电极进行了表征.采用伏安法研究了在磷酸盐缓冲溶液(pH=7.0)中MBCPE/Fe_3O_4NPs/DPB电极上肼的电化学行为.作为电化学传感器,MBCPE/Fe_3O_4NPs/DPB电极对肼氧化反应表现出极高的电催化活性.在DPB存在下,肼的氧化电势下降,但其催化电流增加.电催化电流与肼浓度在0.1–0.4和0.7–12.0μmol/L二个区间内表现出线性关系,检测限为18.0 nmol/L.另外,研究了MBCPE/Fe_3O_4NPs/DPB电极同时检测肼和苯酚的性能.伏安实验结果显示,苯酚的线性区域为100–470μmol/L,检测限为24.3μmol/L.采用此电极检测了水样品中的肼和苯酚.     

MWCNTs-rGO/PDDA-AuNPs复合膜修饰电极对莱克多巴胺的灵敏检测

采用自组装方法,将聚二烯丙基二甲基氯化铵(PDDA)功能化的金纳米颗粒(Au NPs)负载于多壁碳纳米管(MWCNTs)-还原型氧化石墨烯(r GO)夹层,再涂覆于玻碳电极(GCE)上,制备了纳米复合膜修饰电极MWCNTs-r GO/PDDA-Au NPs/GCE.采用透射电子显微镜(TEM)和紫外-可见光谱(UV-Vis)对修饰膜的形貌及结构进行表征.探讨了其对莱克多巴胺(Rac)的循环伏安行为,结果表明MWCNTs-r GO/PDDA-Au NPs纳米复合物对Rac表现出显著的电催化氧化特性.采用差分脉冲伏安法测得该复合膜修饰电极对Rac检测的线性范围为0.036~4.5μmol/L,检出限为6.35 nmol/L(S/N≥3),且显示出良好的抗干扰能力、稳定性及重现性.采用该方法检测猪血清及猪尿样中的Rac,回收率达95.4%~105.9%,表明该复合膜修饰电极对实际样品中Rac的检测具有潜在应用价值.     

聚(3-氨基-5-巯基-1,2,4-三唑)/多壁碳纳米管修饰的玻碳电极同时检测尿酸、黄嘌呤与次黄嘌呤

采用滴涂法得到多壁碳纳米管(MWCNTs)修饰的玻碳电极(GCE),通过电沉积方法将3-氨基-5-巯基-1,2,4-三唑(TA)沉积在MWCNTs/GCE表面,制备了聚(3-氨基-5-巯基-1,2,4-三唑)/多壁碳纳米管修饰电极(p TA/MWCNTs/GCE)。采用循环伏安法(CV)和示差脉冲伏安法(DPV),研究了尿酸(UA)、黄嘌呤(XA)和次黄嘌呤(HX)在该修饰电极上的电化学行为。结果表明,该修饰电极对UA、XA和HX均有较好的电催化活性作用,能实现对3种物质的同时测定。UA、XA和HX在该修饰电极上的线性范围分别为9.0~739.0、2.0~259.0、1.0~353.0μmol/L;检出限分别为0.67、0.17、0.33μmol/L。该修饰电极已成功用于尿液和血清实际样品中UA、XA和HX的同时测定,回收率为98.8%~105.5%。     

甲醛在铂纳米颗粒修饰电极上的电化学响应及其应用

用铂纳米颗粒直接修饰玻碳电极,制成了具有大表面积的纳米铂修饰电极.该电极对甲醛的电催化氧化明显优于铂盘电极,电化学响应显著.在碱性介质循环伏安分析中,氧化峰电流与甲醛浓度呈良好的线性关系,检出限为3.8×10(-5)mol/L(1.3μg/L),且多次测量中甲醛氧化峰电流相对标准偏差为1.9%.该修饰电极可用于腐竹提取...     

咖啡因的碳纳米管负载纳米铂修饰电极的伏安法测定

将碳纳米管(CNTs)分散在疏水性表面活性剂双十六烷基磷酸(DHP)中形成稳定、均相的分散液,制备了一种新型的碳纳米管负载纳米铂修饰电极(Pt/CNTs/GCE).采用差分脉冲伏安法研究了咖啡因在该电极上的电化学行为;在0.01 mol/L的H2SO4溶液中,咖啡因在Pt/CNTs/GCE修饰电极上于1.33 V处出现一灵敏的氧化峰;该修饰电极对咖啡因的氧化有良好的电催化活性,在最佳测试条件下,氧化峰电流与咖啡因的浓度在1.0×10-6 ～1.0×10-4 mol/L范围呈现良好的线性关系,检出限达2×10-7 mol/L;该修饰电极表现出良好的稳定性和重现性,5次平行测量的RSD为2.03%;计时电量法求得扩散系数为3.58×10-5 cm2/s.方法用于茶叶等样品中咖啡因含量的测定,结果令人满意.     

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.     

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.     

用聚(L-蛋氨酸)/纳米金修饰玻碳电极同时灵敏检测多巴胺和尿酸简

A novel electrochemical sensor was fabricated by electrodeposition of gold nanoparticles on a poly(L-methionine) (PMT)-modified glassy carbon electrode (GCE) to form a nano-Au/PMT composite-modified GCE (nano-Au/PMT/GCE). Scanning electron microscopy and electrochemical techniques were used to characterize the composite electrode. The modified electrode exhibited considerable electrocatalytic activity towards the oxidation of dopamine (DA) and uric acid (UA) in phosphate buffer solution (pH = 7.00). Differential pulse voltammetry revealed that the electrocatalytic oxidation currents of DA and UA were linearly related to concentration over the range of 5.0×10^-8 to 10^-6 mol/L for DA and 7.0×10^-8 to 10^-6 mol/L for UA. The detection limits were 3.7×10^-8 mol/L for DA and 4.5×10^-8 mol/L for UA at a signal-to-noise ratio of 3. According to our experimental results, nano-Au/PMT/GCE can be used as a sensitive and selective sensor for simultaneous determination of DA and UA.     

Platinum nanoparticles supported MoS2 nanosheet for simultaneous detection of dopamine and uric acid

Herein, platinum nanoparticles-decorated molybdenum disulfide(Pt NPs@MoS_2) nanocomposite has been synthesized via a microwave-assisted hydrothermal method, which was characterized by transmission electron microscopy(TEM) and powder X-ray diffraction(XRD). This MoS_2-based nanocomposite modified glass carbon electrode(Pt NPs@MoS_2/GCE) exhibited excellent electrocatalytic activity toward dopamine(DA) and uric acid(UA) due to their synergistic effect. Two well-defined oxidation peaks of DA and UA were obtained at Pt NPs@MoS_2/GCE with a large peak separation of 160 m V(DA-UA), suggesting that the modified electrode could individually or simultaneously analyze DA and AA. Under the optimal conditions, the peak currents of DA and UA were linearly dependent on their concentrations in the range of 0.5–150 and 5–1000 mmol/L with detection limit of 0.17 and 0.98 mmol/L, respectively. The proposed MoS_2-based sensor can also be employed to examine DA and UA in real samples with satisfactory results. Therefore, the Pt NPs@MoS_2 nanocomposite might offer a good possibility for electrochemical sensing and other electrocatalytic applications.     

基于复合膜修饰玻碳电极对黄嘌呤的选择性测定

制备了一种新型电化学传感器--聚2,2-联吡啶(Pbpy)/1-苯基-3-甲基-4-(α-呋喃甲酰基)-5-吡唑啉酮(HPM-α-FP)/玻碳(GC)复合膜修饰电极。 运用循环伏安法和脉冲伏安法研究了药物分子黄嘌呤(XN)的电化学行为及反应机理。 与裸GCE和Pbpy/GCE电极相比,复合修饰电极Pbpy/HPM-α-FP/GCE测定XN的氧化峰电流和检测灵敏度均有显著提高,表明聚2,2-联吡啶与酰基吡唑啉酮产生了协同增效作用。 当pH=8,扫速为100 mV/s的条件下,氧化峰电流与黄嘌呤浓度在6×10-7～1×10-5 mol/L和1×10-5～1×10-4 mol/L之间均呈现良好的线性关系,检出限为1×10-8 mol/L。 该修饰电极可用于共存尿酸(UA)、抗坏血酸(AA)体系及实际样品的黄嘌呤含量测定。     

Electrocatalytic Detection of Uric Acid on Nitrogen‐Doped Graphene Modified Electrode and Its Application

Nitrogen‐doped graphene (NG) was used to modify a glassy carbon electrode (GCE), which was applied to the voltammetric detection of uric acid (UA). Because of the presence of NG on the GCE surface, the modified electrode showed excellent electrocatalytic ability for UA oxidation with increase of the peak current and decrease of the peak potential. Compared to that of the traditional GCE, the overpotential of the oxidation peak decreased by 50 mV. Electrochemical performance of UA was studied on NG/GCE in detail, which showed a quasi‐reversible, diffusional‐controlled process. Electrochemical parameters including the charge transfer coefficient (α ), the number of electron transfer (n ), and the diffusional coefficient (D ) were calculated. At the optimal conditions, the oxidation peak current was linear, with UA concentration from 0.1 to 10.0 μmol/L as revealed by differential pulse voltammetry, and the detection limit was estimated as 0.042 μmol/L (3σ). The UA content in the urine sample of a healthy volunteer was determined by the proposed method with a recovery of 98.7–102.3%.     

Gold Nanoparticles-electrochemically Reduced Graphene Oxide/Poly(indole-5-carboxylic acid) Nanocomposite for Electrochemical Non-enzymatic Sensing of Hydrogen Peroxide

Herein, co-electrodeposition of AuNPs and ERGO onto GCE was conducted to prepare the modified electrode, GCE/AuNPs-ERGO. The poly(indole-5-carboxylic acid) (P(In-5-COOH) was then coated onto the GCE/AuNPs-ERGO with the help of electropolymerization. FT-IR, FE-SEM and EDX, and XRD techniques were employed to characterize the prepared nanocomposite. The nanocomposite modified electrode (GCE/AuNPs-ERGO/P(In-5-COOH)) was examined for the electrochemical reduction of H₂O₂ using chronoamperometry. A high reduction current for H₂O₂ was observed due to the synergistic effect between AuNPs-ERGO and P(In-5-COOH). The proposed sensor demonstrated a wide linear range of 0.025–750 μmol L⁻¹, with a LOD of 0.008 μmol L⁻¹ at −0.4 V. Furthermore, the developed sensor was applied for the detection of H₂O₂ in fetal bovine serum and urine samples.     

Simultaneous determination of uric acid, xanthine and hypoxanthine at poly(pyrocatechol violet)/functionalized multi-walled carbon nanotubes composite film modified electrode

A sensitive and selective electrochemical method was developed for simultaneous determination of uric acid (UA), xanthine (XA) and hypoxanthine (HX) based on a poly (pyrocatechol violet)/carboxyl functionalized multi-walled carbon nanotubes composite film modified electrode. The preparation and basic electrochemical performance of the novel composite film modified glassy carbon electrode were investigated in details. The electrochemical behaviors of UA, XA and HX at the modified electrode were studied by cyclic voltammetry. The results showed that this new electrochemical sensor exhibited excellent electrocatalytic activity towards the oxidation of the three analytes. The mechanism of catalysis was discussed. The anodic peaks of the three species were well defined with lowered oxidation potential and enhanced oxidation peak currents, so the modified electrode was used for simultaneous voltammetric measurement of UA, XA and HX by differential pulse voltammetry. Under the optimum conditions, the detection limits were 0.16 μmol L(-1) for UA, 0.05 μmol L(-1) for XA and 0.20 μmol L(-1) for HX, respectively (S/N of 3). The proposed method has been successfully applied to simultaneous determination of UA, XA and HX in human serum samples.     

Immobilization of DNA on a glassy carbon electrode based on Langmuir–Blodgett technique: application to the detection of epinephrine

A double-stranded (ds) DNA-octadecylamine Langmuir–Blodgett film was attached to the surface of glassy carbon electrode (GCE) to create a novel voltammetric sensor (DNA-LB/GCE) for epinephrine (EP). Atomic force microscopy and electrochemical impedance spectroscopy were employed to study the characteristic of the DNA-LB film. The electrochemical behavior of EP at the modified electrode was investigated in pH 6.0 phosphate buffer solutions by cyclic voltammetry and amperometric methods. Compared with bare GCE, the DNA-LB/GCE sensor demonstrated an electrocatalytic effect on the oxidation of EP. In addition, the sensor shows excellent selectivity for EP detection, being free of interference from excess ascorbic acid and uric acid, and the method was also applied successfully to detect EP in the human urine samples.