基于聚对苯二甲酸乙二醇酯薄膜的石墨烯/金纳米粒子/葡萄糖氧化酶柔性电极的制备及检测葡萄糖

采用化学气相沉积法生长多晶石墨烯(Graphene, G),转移至聚对苯二甲酸乙二醇酯(PET)薄膜表面,通过控制金溶胶蒸发速率,在多晶石墨烯表面组装均匀分布的亚单层金纳米粒子(AuNPs);然后修饰巯基乙酸,通过共价交联反应将葡萄糖氧化酶固定于AuNPs表面,构建基于PET膜的石墨烯/金纳米粒子/葡萄糖氧化酶(G/AuNPs/GOD)柔性电极.此电极在工作电位0.6 V(vs.SCE电极)、pH 7.0磷酸盐缓冲溶液、室温25℃条件下,差分脉冲伏安法响应电流与被测葡萄糖浓度在0.05~10.55 mmol/L范围内呈线性关系,线性方程为I(108A)=0.2629 C(mmol/L)+1.4149,线性相关系数 r=0.9955,检出限1 μmol/L (3σ). G/AuNPs/GOD柔性电极的制备可为特定环境和可穿戴设备的葡萄糖检测提供了新的途径和方法,拓展了葡萄糖检测的应用范围.     

金纳米粒子-壳聚糖-石墨烯纳米复合材料的制备及其在生物电化学中的应用

通过共价键作用和原位还原法制备了金纳米粒子/壳聚糖-石墨烯纳米复合材料(AuNPs/Chit-GP). 利用FT-IR, UV-vis, TEM以及XRD对所合成的纳米复合物的结构和形貌进行了表征. AuNPs/Chit-GP呈现明显的正电荷, 因此可通过静电相互作用固载葡萄糖氧化酶(GOD), 并构建GOD/AuNPs/Chit-GP/GC修饰电极. 该修饰电极不仅可成功地实现GOD与电极间的直接电子转移, 还对葡萄糖表现出良好的催化性能. 实验结果表明, 其催化的线性范围为2.1～5.7 μmol/L, 检出限为0.7 μmol/L, 灵敏度为79.71 mA·cm^-2·mM^-1. 这种集金属纳米粒子、生物相容性高分子以及石墨烯为一体的纳米复合物的构筑为无媒介体的电化学生物传感器的研究提供了一个良好的平台.     

纳米金胶增强葡萄糖生物传感器的构建

将纳米金胶(AuNPs)和羟基磷灰石(HAp)按一定比例混合制备了新型复合膜用于葡萄糖氧化酶(GOD)的固定,构建了高灵敏的葡萄糖传感器。由于纳米金胶的存在,葡萄糖氧化酶的直接电化学性质得以增强,在去除氧气的PBS(pH 7.0)介质中,固定在复合膜内的GOD表现出一对良好的氧化还原峰。在饱和氧气条件下,当加入一定量的葡萄糖时,由于GOD催化葡萄糖氧化消耗溶液中的溶解氧,-0.8 V处溶解氧的还原峰电流降低,且峰电流降低的量与葡萄糖浓度在0.02～1.62 mmol/L范围内呈线性相关,检出限为5.0μmol/L,检测灵敏度达9.91 mA.mol-1.L,可实现对葡萄糖的快速检测。     

基于聚对氨基苯磺酸、功能化石墨烯和纳米金修饰电极的构筑及用于双酚A的测定

通过电聚合方法制备聚对氨基苯磺酸修饰的玻碳电极（GCE/pABSA）,然后把带有正电荷的超支化聚乙烯亚胺功能化还原氧化石墨烯（BPEIGr）和带有负电荷的金纳米粒子（AuNPs）依次修饰到电极上,制得GCE/pABSA/BPEIGr/AuNPs修饰电极。研究了双酚A在GCE/pABSA/BPEIGr/AuNPs修饰电极上的电化学行为。结果表明,所制备的修饰电极对双酚A有良好的电催化效果,在pH 7.0的PBS溶液中进行循环伏安扫描,双酚A在0.2～0.8 V范围内出现1个不可逆的氧化还原峰。采用差分脉冲伏安法（DPV）对双酚A进行了检测,在优化的条件下,双酚A的浓度在0.05～10μmol/L范围内与氧化峰电流呈线性关系,检出限为0.02μmol/L(3σ)。将基于此修饰电极的传感器用于浑河水和自来水中双酚A含量的测定,加标回收率在97.0%～105.0%之间。     

基于纳米复合材料/壳聚糖膜的葡萄糖生物传感器研究

采用纳米普鲁士蓝/金纳米粒子/壳聚糖(nano-PB/AuNPs/Chit)复合膜固定葡萄糖氧化酶(GOD)构建新型葡萄糖生物传感器。通过电化学阻抗谱以及电流-时间曲线法(I-t)研究了传感器的电化学特性。结果表明,传感器在葡萄糖浓度为0.01～1.0 mmol/L范围内呈线性,响应灵敏度为68.15μA.(mmol/L)-1.cm-2,表观米氏常数为5.1 mmol/L。该传感器可用于糖尿病人血糖的测定。     

纳米金葡萄糖氧化酶修饰电极对葡萄糖的电化学行为研究

利用自组装技术固定化酶稳定的优点,及纳米金的高灵敏电催化作用制备了纳米金修饰葡萄糖氧化酶修饰金电极.结果表明,制备的修饰电极对葡萄糖具有很好的电催化氧化功能.在选择的条件下,修饰电极对葡萄糖在0～28 mmol/L浓度范围内呈线性响应,响应时间为15 s,检出限为0.27 mmol,响应电流的平均密度为33.52 nA/cm2,两周后响应值保持88%,可满足实际应用要求.     

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。     

新型抗癌药物长春地辛的电化学研究

以纳米金(AuNPs)/聚乙烯吡咯烷酮(PVP)为修饰剂,制备了一种新型修饰电极AuNPs/PVP/Au/CME,运用循环伏安法,详细探究了长春地辛(Vindesine,VDS)的电化学行为,研究了最佳测定条件。结果表明,修饰电极在pH=7.19的Na_2B_4O_7-KH_2PO_4底液中进行循环伏安扫描时,在0.39V处产生一个灵敏的还原峰P_1和一个不太灵敏的氧化峰P_2。用差分脉冲伏安法研究了修饰电极对VDS的电化学响应,结果表明响应电流与VDS浓度在1.0×10~(-8)~1.0×10~(-4) mol/L范围内呈良好的线性关系,相关系数R~2=0.9972,检出限为3.2×10~(-9) mol/L。AuNPs/PVP/Au/CME修饰电极对长春地辛的电化学检测具有高的灵敏度和好的选择性。     

壳聚糖-纳米金-葡萄糖氧化酶生物传感器的制备及其应用于葡萄糖的测定

采用了一种简便快捷的电沉积方法制备了壳聚糖-纳米金复合膜并应用于葡萄糖生物传感器的构建.氯金酸和壳聚糖的混合液在玻碳电极表面电化学还原为金纳米粒子,再将葡萄糖氧化酶通过戊二醛交联的方式固定在纳米金复合膜修饰的玻碳电极表面,制成一种新型的葡萄糖氧化酶生物传感器.该传感器对葡萄糖的响应十分快速,在5 S内即达到平衡.测定葡萄糖的线性范围为20μmol·L-1～5 mmol·L-1,检出限(3S/N)为12μmol·L-1.     

硅溶胶-凝胶包埋纳米金和酶的葡萄糖生物传感器

采用溶胶-凝胶技术将金纳米粒子和葡萄糖氧化酶一次性固定于硅溶胶-凝胶的网络结构中,制备了葡萄糖生物电化学传感器并优化了传感器的制备条件。酶电极对葡萄糖具有良好的电化学响应,葡萄糖浓度在0.02~2.0 mmol/L范围内和催化电流呈线性关系,检出限为0.005 mmol/L。酶电极在4 ℃下贮存100 d后对葡萄糖的响应仅下降8%。该酶电极灵敏度高、响应快、稳定性好。     

氧化铜-过氧化聚吡咯-还原氧化石墨烯复合膜修饰电极非酶检测葡萄糖

先以氧化石墨烯(Graphen oxide,GO)为阴离子掺杂剂,采用电化学聚合法制备了聚吡咯-氧化石墨烯复合膜(PPy-GO)。分别在0.10 mol/L Na Cl和0.10 mol/L NaOH溶液中对其进行还原和过氧化处理,制得过氧化聚吡咯-还原氧化石墨烯复合膜(OPPy-ERGO)。再以此OPPy-ERGO复合膜为载体,采用电化学沉积法制备了氧化铜-过氧化聚吡咯-还原氧化石墨烯复合膜修饰电极(CuO-OPPy-ERGO/CCE)。通过扫描电镜和电化学方法对此电极进行表征,研究了葡萄糖在此修饰电极上的电化学行为。结果表明,此电极对葡萄糖的电氧化过程表现出高的催化活性和良好的抗干扰能力。在0.20 mol/L NaOH溶液中,安培法检测葡萄糖的线性范围为5.0×10~(-7)~1.0×10~(-3)mol/L,检出限(3Sb)为2.0×10~(-7)mol/L,灵敏度为121.8μA/(mmol·L~(-1))。该电极用于血清中葡萄糖含量的测定,加标回收率为96.0%~110.1%。     

Preparation and Characterization of a Tin Pentacyanonitrosylferrate‐Modified Carbon Ceramic Electrode: Application to Electrocatalytic Oxidation and Amperometric Detection of L‐Cysteine

The sol‐gel technique was used to construct tin pentacyanonitrosylferrate (SnPCNF) modified composite carbon ceramic electrode (CCE). This involves two steps: construction of CCE containing metallic Sn powder and then electrochemical creating of SnPCNF on the surface of CCE. The SnPCNF modified CCE (SnPCNFlCCE) was characterized by energy‐dispersive X‐ray (EDX), FTIR and cyclic voltammetry (CV) techniques. The SnPCNF film showed electrocatalytic activity toward the oxidation of L ‐cysteine. A linear calibration plot was obtained over the L ‐cysteine concentration range 1–51 μM using chronoamperometry. L ‐cysteine was determined amperometrically at the surface of this modified electrode. The detection limit (for a signal to noise of 3) and sensitivity were found to be 0.62 μM and 126 μA/mM, respectively.     

聚邻氨基酚/Ni2+修饰碳糊电极的制备及其对葡萄糖的电催化氧化

以循环伏安法在碳糊电极(CPE)表面上修饰聚邻氨基酚膜(P-OAP),再以浸泡吸附法在此膜中嵌入金属离子Ni2 ,制成Ni/P-OAP/CPE。该电极在0.09mol/LNaOH溶液中通过90圈扫描活化后,在-0.15至0.65V区间出现一对峰形良好且稳定的氧化还原峰。循环伏安实验发现,Ni/P-OAP/CPE对葡萄糖的电氧化有良好的催化特性,催化活性受薄膜的厚度、薄膜中Ni2 的浓度、电极的活化时间以及电解液组成的影响。实验结果表明:该电极是一种良好的无酶葡萄糖传感器。     

碳纳米管负载氢氧化镍修饰电极的制备及应用

采用表面滴涂结合循环伏安法制备了碳纳米管负载氢氧化镍修饰电极(Ni(OH)2/MWNT/CCE)。研究了该修饰电极对葡萄糖的电催化氧化性能。结果表明,该修饰电极对葡萄糖具有良好的电催化氧化活性。在优化条件下,安培法检测葡萄糖的线性范围为2.0×10-7～5.7×10-4 mol.L-1(r=0.999 9,s=2 786.5μA.(mmol.L-1)-1.cm-2)和5.7×10-4～2.7×10-3 mol.L-1(r=0.999 1,s=2 005.2μA.(mmol.L-1)-1.cm-2),检出限(3sb)为8.0×10-8 mol.L-1。该法已成功用于血清中葡萄糖含量的测定。     

纳米铜/石墨烯-壳聚糖复合膜修饰电极及其对葡萄糖的直接测定

以石墨烯-壳聚糖复合膜修饰玻碳电极,并在此复合膜上电沉积纳米铜,用于葡萄糖的无酶检测。以扫描电镜、傅立叶红外光谱及电化学交流阻抗谱对该复合膜微观形态进行表征,以循环伏安法、计时电流法对该电极的电化学行为进行研究。实验结果表明,在0.1 mol/L Na OH溶液中修饰电极对葡萄糖具有良好的催化氧化作用,该电极对葡萄糖的检测线性范围为5.6×10-5~1.2×10-3mol/L,检出限(S/N=3)为2.3×10-5mol/L。该修饰电极对样品的检测具有良好的稳定性、重现性。     

Direct Electrochemistry and Electrocatalysis of Hemoglobin at PAMAM Dendrimer-MWNTs-Au Nanoparticles Composite Film Modified Glassy Carbon Electrode

The direct electron transfer of hemoglobin at the PAMAM-MWNTs-AuNPs composite film modified glassy carbon electrode was studied. In a phosphate buffer solution(PBS, pH=7.0), the formal potential(E 0' ) of Hb was –0.105 V versus SCE, the electron transfer rate constant was 4.66 s –1 . E 0′ of Hb at the modified electrode was linearly varied in a pH range of 5.0—8.0 with a slope of –49.2 mV/pH. The Hb/PAMAM-MWNTs-AuNPs/GCE gave an ex-cellent electrocatalytic response to the reduction of hydrogen peroxide. The catalytic current increased linearly with H 2 O 2 concentration in a range of 1.0×10 ?6 to 2.2×10 ?3 mol/L. The detection limit was 2.0×10 ?7 mol/L at a signal to noise ratio of 3. The Michaelis-Menten constant(K ma pp ) was 2.95 mmol/L.     

茜素S复合铋膜电极电催化还原氯霉素

本研究采用电化学法制备茜素S复合铋膜修饰玻碳电极,利用循环伏安法、差示脉冲伏安法(DPV)研究氯霉素在茜素S复合铋膜电极上的电化学行为,并对其电化学测试条件进行优化.在pH 7.0的KH2PO4-Na2HPO4缓冲溶液中,氯霉素在-0.63 V处产生一灵敏的不可逆还原峰,显示出复合铋膜对氯霉素的还原有很好的催化作用.D...     

碳纳米管负载纳米金-石墨烯量子点修饰电极电化学检测过氧化氢

采用过氧化氢刻蚀法制备石墨烯量子点(GQDs),再采用原位化学还原法制备金纳米粒子-石墨烯量子点纳米复合物(Au NPs-GQDs),最后以聚二甲基二烯丙基氯化铵(PDDA)为交联剂将上述纳米复合物组装于多壁碳纳米管表面,制得金纳米粒子-石墨烯量子点-PDDA-多壁碳纳米管复合材料(Au NPs-GQDsPDDA-MWCNTs)。通过荧光光谱法、紫外-可见吸收光谱法和透射电子显微镜对上述复合材料进行表征。采用滴涂法制得该复合材料修饰的玻碳电极,研究了过氧化氢在该电极上的电化学行为。结果表明:在石墨烯量子点、金纳米粒子和多壁碳纳米管三者的协同作用下,该电极对过氧化氢的电氧化表现出强的催化活性。在优化条件下,安培法检测H_2O_2的线性范围为2.0×10~(-8)~1.5×10~(-3)mol/L,检出限(3sb)为8.0×10~(-9)mol/L,灵敏度为61.6μA/(mmol·L~(-1))。     

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.     

Preparation and Electrochemical Behaviour of Silver Pentacyanonitrosylferrate Film Modified Glassy Carbon Electrode and Its Electrocatalytic Oxidation to L‐cysteine

A glassy carbon (GC) electrode modified with silver pentacyanonitrosylferrate (AgPCNF) film as a redox mediator was fabricated. Cyclic voltammetry was used to study the redox property of AgPCNF modified electrode. The modified electrode showed a well‐defined redox couple due to [Ag^IFe^III/II(CN)₅NO]^1‐/2‐system. The effects of scan rates, supporting electrolytes and solution pHs were studied on the electrochemical behavior of the modified electrode. The feasibility of using the AgPCNF modified electrode to measure L ‐cysteine was investigated. It showed an excellent electrocatalytic activity towards the oxidation of L ‐cysteine and the anodic currents were proportional to the L ‐cysteine concentration in the range of 0.1 μM to 20 μM, the linear regression equation is I_pa(μA) = ‐68.58 ‐ 5.78C_{L ‐cysteine} (μM), with a correlation coefficient 0.998 for N = 23. The detection limit was down to 3.5 × 10^‐8 M (three times the ratio of signal to noise).