无金属可见光诱导原子转移自由基聚合法制备聚丙烯酰胺@氧化石墨烯/纳米钯复合物修饰电极及其对乙醇的检测

在金电极表面,用无金属可见光诱导原子转移自由基聚合(MVL ATRP)的方法制备聚丙烯酰胺@氧化石墨烯/纳米钯复合物修饰电极(Au/PAM@GO/Pd)。采用电化学循环伏安法(CV)、交流阻抗法(EIS)、扫描电子显微镜(SEM)、能量色散X射线光谱法(EDS)对Au/PAM@GO/Pd电极进行表征,结果表明在金电极表面成功制备了复合物。利用Au/PAM@GO/Pd电极作为电化学传感器,该传感器能成功地检测溶液中的乙醇。在最佳条件下,利用差分脉冲伏安法(DPV)该传感器检测乙醇的线性范围为1.0×10-8~1.0 mol/L,检出限(S/N=3)为1.3×10-9 mol/L,线性相关系数为0.996。     

纳米金/石墨烯修饰电极的制备及其对多巴胺的测定

利用电化学还原方法制备纳米金/石墨烯修饰玻碳电极,研究了多巴胺(DA)在该修饰电极上的电化学行为,建立了电化学测定多巴胺的新方法。结果表明,在磷酸盐缓冲溶液中,此修饰电极对多巴胺的电化学响应具有很好的催化作用。利用差示脉冲伏安技术对多巴胺的电化学氧化进行定量分析,多巴胺的氧化峰电流与其浓度在1.0×10-7～1.0×10-5mol/L范围内呈良好的线性关系,检测限低至4.0×10-8mol/L。该修饰电极适于多巴胺的分析检测。     

基于功能化石墨烯-聚乙烯醇复合膜固定乙酰胆碱酯酶的甲拌磷传感器

将功能化离子液体修饰石墨烯(IL-GR)分散在聚乙烯醇(PVA)中,制得IL-GR-PVA分散液,与乙酰胆碱酯酶(ACh E)溶液混匀后滴涂在电极表面,利用PVA良好的成膜特性,制得新型有机磷检测酶电极ACh E/IL-GR-PVA/GCE,并用于有机磷农药的检测。采用透射电镜(TEM)表征了IL-GR的形貌,采用循环伏安法(CV)和差示脉冲伏安法(DPV)研究了酶电极的电化学性质。结果表明,IL-GR-PVA复合膜具有良好的导电性和生物相容性,能很好地保持ACh E的生物活性,并显著促进了其电化学过程。在优化实验条件下,抑制率(I%)与甲拌磷浓度的负对数在1.0×10-14~1.0×10-9mol/L和1.0×10-9~1.0×10-6mol/L范围内呈良好的线性关系,检出限(S/N=3)为8.0×10-15mol/L。该传感器制备简单,稳定性好,灵敏度高,为有机磷农药的测定提供了新方法。     

固定丝素蛋白膜中的联吡啶钌电化学发光行为的研究与应用

基于苯海拉明对联吡啶钌(Ru(bpy)2+3)的电化学发光的增敏作用和丝素蛋白-联吡啶钌复合膜修饰玻碳电极稳定好的特点,建立了一种以丝素蛋白多孔膜-联吡啶钌复合物修饰的玻碳电极电化学发光检测苯海拉明的新方法.结果表明,该修饰电极具有很好的电化学活性和电化学发光(ECL)响应.在最佳实验条件下,苯海拉明浓度在1.0×10-4～1.0×10-7 mol/L范围内与其相对发光强度呈良好的线性关系(r=0.9989); 检出限为2.3×10-7 mol/L(S/N=3).连续平行测定3.78×10-5 mol/L苯海拉明5次,发光强度的RSD为1.76%. 用于实际样品中苯海拉明的测定,结果满意.     

纸基葡萄糖电化学生物传感器的研究及应用

基于纳米金的自催化无电沉积镀金技术,采用混合纤维素滤膜作为模板,制备了一种纳米多孔纸基薄膜金电极。以该金滤膜电极作为基底电极,使用Nafion溶液分散的碳纳米管-纳米铂(PtNPs)复合材料作为载体,实现了葡萄糖氧化酶(GOD)的直接电化学,并建立了一种低成本的纸基葡萄糖电化学传感器。该传感器对葡萄糖具有良好的安培响应,葡萄糖浓度在5.0×10-6~2.5×10-3 mol/L范围与其0.55V处的氧化电流呈良好的线性关系(R=0.999),检测限(S/N=3)为1.0×10-6 mol/L。制备了8支传感器,对25μmol/L葡萄糖进行检测,结果的相对标准偏差为6.03%,表明该传感器具有较好的重现性。     

电化学发光-分子印迹传感器的制备及其在海洛因检测中的应用

利用掺杂多壁碳纳米管(MWNTs)的Nafion膜在玻碳电极上固定联吡啶钌(Ru(bpy)2+3),制得Ru(bpy)2+3/Nafion/MWCNT修饰电极。为了提高修饰电极的选择性,通过溶胶-凝胶技术,对该电极进一步修饰了溶胶-凝胶分子印迹膜,制得电化学发光-分子印迹传感器。优化了扫速、pH值、富集时间等检测条件,传感器显示出既具电化学发光技术的灵敏性和分子印迹技术的选择性。在优化条件下,即pH 7.0的磷酸盐缓冲溶液中,以100 mV/s扫速,富集5 min,对海洛因进行检测,在1.0×10!10~1.0×10!14mol/L范围内有良好线性关系,检出限可达到4.0×10!15mol/L(S/N=3)。传感器直接应用于唾液和尿液中海洛因的测定,回收率达到97%~104%。     

纳米金/丝素复合膜修饰电极制备及对对苯二酚的电催化作用

将丝素还原HAuCl4制备的纳米金/丝素溶胶修饰在金电极表面制备了纳米金/丝素复合膜修饰电极,用于对苯二酚的催化氧化。实验表明,该修饰电极具有很好的电化学性能,在pH3.55磷酸盐缓冲溶液中以该修饰电极对对苯二酚进行检测,对苯二酚在4.0×10-6~1.0×10-4mol/L浓度范围内,其氧化峰电流与浓度呈良好的线性关系,其线性回归方程为i(μA)=0.2614 5.3539c,r=0.9995;检出限为2.0×10-7mol/L,灵敏度良好,用于实际样品分析,结果令人满意。     

尼泊金乙酯分子印迹膜电化学传感器的制备

以邻苯二胺为功能单体,尼泊金乙酯为模板分子,通过电化学聚合在玻碳电极表面制备了尼泊金乙酯分子印迹膜,采用循环伏安法及方波伏安法,以K3[Fe(CN)6]为电活性探针,建立了间接测定尼泊金乙酯的分析方法。实验结果表明,制备的分子印迹膜电化学传感器对尼泊金乙酯具有较高的选择性和灵敏度,测定尼泊金乙脂的线性范围为2.5×10-6~1.0×10-5 mol/L,检出限为8.61×10-8 mol/L。     

基于Nafion-聚苋菜红-石墨烯纳米复合膜修饰玻碳电极的一氧化氮生物医学传感

通过简单可控的滴涂成膜法和电聚合法,将Nafion-聚苋菜红-石墨烯纳米复合膜固定于玻碳电极表面,构建了一种新型NO生物医学传感界面。电化学表征表明,纳米复合膜对于NO的电化学氧化具有良好的催化效应。借助于电子扫描显微镜技术和电化学交流阻抗技术对纳米复合膜的电催化机理进行了探讨,并对传感器的性能进行了考察。结果表明,该传感器具有较宽的线性范围(1.0×10~(-7)～5.1×10~(-4) mol/L),检出限低至1.8×10~(-8) mol/L。方法具有重现性好、稳定性好、灵敏度高以及抗干扰能力强等优点。将该传感器应用于小鼠母瘤神经细胞释放NO的监测,取得了令人满意的结果。     

L-丝氨酸/壳聚糖/石墨烯/纳米金修饰电极的制备及应用

将L-丝氨酸(L-Serine)电聚合到裸金电极表面,再将壳聚糖(CS)、纳米金(Nano-Au)、石墨烯(GO)混合液滴涂在L-丝氨酸修饰的金电极上,制成L-Serine/GO/Nano-Au/CS/Au/CME电化学传感器.考察了胞嘧啶在该传感器上的电化学行为,优化了实验条件.结果表明,该传感器对胞嘧啶有良好的选择性和灵敏度,胞嘧啶的浓度在1.0×10~(-7)~1.0×10~(-3)mol/L范围内与峰电流的减小量呈现良好的线性关系,检出限为3.2×10~(-8)mol/L(S/N=3).将该传感器应用于实际样品中测定胞嘧啶,结果令人满意.     

Electrochemical Determination of Phenylethanolamine A Based on Nafion/MWCNTs/AuNPs Modified Carbon Electrode

Phenylethanolamine A (PEA), a β‐agonist, was found to be illegally used as a growth promoter in pigs last year, causing Chinese government's great attention. Here, a sensitive electrochemical method was developed for detecting PEA by immobilization of gold nanoparticles (AuNPs), multiwalled carbon nanotubes (MWCNTs) and Nafion on the surface of a glassy carbon electrode (GCE). The Nafion/MWCNTs/AuNPs film was characterized by scanning electronic micrographs (SEM) and electrochemical impedance spectroscopy (EIS). The electrochemical behaviors of PEA at the modified GCE were investigated in detail. The synergetic effects of AuNPs, MWCNTs and Nafion amplify the electrochemical reduction signal of PEA, and result in high sensitivity for PEA determination. Under the optimal conditions, the electrochemical sensor shows a wide linear range of 0.01 to 10 (mol/L with a detection limit of 0.005 µmol/L. Moreover, the fabricated sensor presents high selectivity and long‐term stability, which paves a new way for simple, rapid, sensitive detection of PEA.     

3D石墨烯修饰的猛杀威分子印迹电化学传感器的制备

以猛杀威为模板分子、丙烯酰胺( AM)为功能单体、马来松香丙烯酸乙二醇酯( EGMRA)为交联剂、自制的3D石墨烯(3D-rGO)为增敏材料,在玻碳电极表面合成分子印迹聚合物,制备检测猛杀威的分子印迹电化学传感器。运用扫描电镜(SEM)对自制3D石墨烯的形貌进行了表征,通过循环伏安法(CV)、差分脉冲伏安法(DPV)和交流阻抗法(EIS)对猛杀威传感器的性能进行了研究。结果表明,猛杀威的浓度在8.0×10-8~8.0×10-6 mol/L范围内与响应电流值呈良好的线性关系,线性相关系数R=0.9954,检出限为7.3×10-8 mol/L (S/N=3),猛杀威分子印迹敏感膜的印迹因子β=3.88,且相对于3种结构类似物的选择因子α垌1,说明此传感器具有良好的选择性。将此传感器应用于生菜样品检测,加标回收率在96.7%~98.7%之间。     

磁性石墨烯修饰辛基酚印迹传感器制备及应用研究

以辛基酚(4-OP)为模板分子,多巴胺为功能单体,采用电聚合技术在磁性石墨烯修饰碳电极表面制备对辛基酚具有高选择性与灵敏性的印迹电化学传感器。采用循环伏安法(CV)和差分脉冲伏安法(DPV)对此印迹传感器的电化学性能进行详细表征;采用扫描电子显微技术对修饰电极的形貌进行表征。结果表明,此印迹电化学传感器对辛基酚具有良好的特异识别性能。采用 DPV 法考察了孵化时间和洗脱溶剂对印迹传感器性能影响,结果表明,最佳孵化时间为14 min。此印迹电化学传感器的响应电流(△IR )与辛基酚在5.0×10-6~5.0×10-9 mol/ L 范围内浓度的负对数(-lgC)呈良好的线性关系,线性方程为△IR ( mA)=-0.25lgC(mol/ L)+2.35,检出限为3.64×10-10 mol/ L (S/ N=3)。此印迹电化学传感器对辛基酚具有良好的选择性和灵敏性,成功用于实际水样中辛基酚的检测,回收率为96.0%~104.0%。     

以3,4-二羟基肉桂酸为介质的多壁碳纳米管糊电极用于检测药物和尿液样品中的谷胱甘肽(英文)

A sensitive and selective electrochemical sensor for the determination of glutathione(GSH) was developed using a modified multiwall carbon nanotube paste electrode with 3,4 dihydroxy cinnamic acid as a mediator.This modified electrode showed very high electrocatalytic activity for the anodic oxidation of GSH.Under the optimized conditions,the electrocatalytic peak current showed a linear relationship with GSH concentration in the range of 0.5-400.0 μmol/L with a detection limit of 0.1 μmol/L GSH.The relative standard deviations for seven successive assays of 5.0 and 25.0 μmol/L GSH were 2.2% and 2.7%,respectively.The modified electrode was used for the determination of GSH compounds in real urine samples.     

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。     

Highly sensitive voltammetric sensor based on catechol-derivative-multiwall carbon nanotubes for the catalytic determination of captopril in patient human urine samples

A new catechol-derivative compound, N-(3,4-dihydroxyphenethyl)-3,5-dinitrobenzamide, was synthesized and used to construct a modified-carbon nanotubes paste electrode. The electro-oxidation of captopril at the surface of the modified electrode was studied using cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. Under the optimized conditions, the differential pulse voltammetric peak current of captopril increased linearly with captopril concentration in the ranges of 6.4×10(-8) to 3.2×10(-48) mol L(-1). The detection limit was 3.4×10(-8) mol L(-1) captopril. The diffusion coefficient and kinetic parameters (such as electron transfer coefficient and the heterogeneous rate constant) for captopril oxidation were also determined. The RSD% for 0.5 and 10.0 μmol L(-1) captopril were 2.1% and 1.6%, respectively. The proposed sensor was successfully applied for the determination of captopril in human patient urine and tablet samples.     

Voltammetric determination of cysteamine at multiwalled carbon nanotubes paste electrode in the presence of isoproterenol as a mediator

A sensitive electrochemical sensor for the determination of cysteamine(CA) was developed using a modified multiwall carbon nanotube paste electrode(MWCNTPE) with isoproterenol(ISPT) as a mediator.This modified electrode showed very high electrocatalytic activity for the anodic oxidation of CA.Under the optimized conditions,the electrocatalytic peak current showed a linear relationship with CA concentration in the range of 0.3–450.0 mmol/L with a detection limit of 0.09 mmol/L CA.The modified electrode was used for the determination of CA in real samples such as urine and drug samples.     

末端可裁切碳纳米管薄膜电极的制备及其双酚A电化学检测应用

通过真空抽滤方法得到均匀致密的高导电多壁碳纳米管(MWCNTs)薄膜,利用聚二甲基硅氧烷(PDMS)对其进行封闭处理,制备出末端可裁切的PDMS基柔性碳纳米管薄膜电极,其裁切端面为电化学传感界面。在十六烷基三甲基溴化铵(CTAB)的增敏作用下,所制备的电化学传感器对双酚A(BPA)具有灵敏的电化学响应,其峰电流与BPA浓度在0.05~0.5μmol/L和0.5~12μmol/L范围内呈良好的线性关系,检测限为50nmol/L。通过电极末端的重复裁切可避免电极污染,并实现电极表面的快速更新和重复使用。对同一支电极进行13次连续裁切,用于10μmol/L BPA的检测,其相对标准偏差为3.4%。将该传感器应用于热敏纸样品中BPA的检测,加标回收率在95%~105%之间。     

基于多壁碳纳米管/纳米铜复合材料的电化学传感器测定槐米中芦丁

以Nafion-多壁碳纳米管(MWNTs)薄膜修饰玻碳电极,采用恒电位法在其表面电沉积纳米Cu,研制了一种新型的芦丁电化学传感器。采用循环伏安法和电化学阻抗谱研究传感器在铁氰化钾-亚铁氰化钾体系中的电化学行为,以考察传感器的电化学性能,采用扫描电镜对传感器表面的形态进行了研究,并利用差分脉冲伏安法测定芦丁的含量。实验结果表明,该传感器对芦丁有较好的催化作用。在优化实验条件下,对芦丁检测的线性范围为1.0×10-8~1.0×10-6 mol/L,检出限为8.4×10-9 mol/L(S/N=3),回收率为98.1%~101%,该传感器制作简单,线性范围宽,灵敏度高,为槐米等样品中芦丁含量的检测提供了一种新的、行之有效的方法。     

An electrochemical sensor for rapid determination of ractopamine based on a molecularly imprinted electrosynthesized o-aminothiophenol film

A simple electrochemical sensor based on a molecularly imprinted polymer film as the recognition element was developed for ractopamine (RAC) detection. This is the first report of a RAC-imprinted film on a gold electrode surface, synthesized through an electrochemical method using o-aminothiophenol as the functional monomer. The imprinting mechanism and experimental parameters affecting the capability of the imprinted film are discussed here. The sensor was successfully applied with constant potential amperometry for RAC detection in an indirect process with potassium ferricyanide as an electrochemical probe. The sensor had a rapid equilibrium time (120?s), high binding affinity and selectivity towards RAC, and with good reproducibility and stability. Under the experimental conditions applied, a linear relationship between the relative amperometric response and RAC ranged from 2.0?×?10(-7) to 1.4?×?10(-6)?mol?L(-1), with a lower limit of detection (LOD) of 2.38?×?10(-8)?mol?L(-1) (signal to noise ratio?=?3). The sensor was tested with feed samples spiked with trace amounts of RAC, with good recoveries between 87.4 and 90.5?%.