首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
将硫堇共价键合到自组装在金电极表面的半胱胺单分子层上,制成了衍生化自组装单分子膜修饰电极,并用电化学方法研究了它的电化学性质,循环伏安图显示其在pH=7.7的磷酸盐缓冲液中,于-0.45~+0.50V(vs.SCE)范围内有2对氧化还原峰,峰电位分别为Epa=214mV,Epc=82mV,E^2pa=-75mV,E^2pc--160mV(vs.SCE),pH在5.0~9.0范围内,峰1有2个质子参  相似文献   

2.
血红蛋白在裸银电极上的直接电化学及其分析应用   总被引:3,自引:0,他引:3  
报道了血红蛋白(Hb)在裸银电极上的电化学氧化还原行为,在+0.4-0.2V(vs.SCE)电位范围内于PH=4.5的0.1mol/LNaAc-HAc底液中,血红蛋白产生一对灵敏的氧化还原峰,峰电位之差EO 0.25V(扫描速度20mV/s)。动力学研究表明,电极反应的电子转移数n为0.94,表观电子传递速度率常数 K3为0.032s^-1,连续电拉扫描30min,峰电流变化分别为0.1  相似文献   

3.
本文用恒电位,恒电流,循环扫描等电化学方法,首次制备了邻菲绕啉(0-phen)聚合膜修饰电极,在0.01mol/LKClO4水溶液中,其氧化与还原过程的峰电位分别为+0.04V和-0.53V(vs.SCE),该修饰电极在酸性,中性,碱性条件下均具有良好的稳定性,能较好地改善K3Fe(CN)6和Vk3在电极上的氧化还原性质,对维生素C和肼的氧化有很好的催化作用,其氧化峰电位分别降低220mV和562  相似文献   

4.
将酞菁镍(NiPc)掺入阳离子表面活性剂双十二烷基二甲基溴化铵(DDAB)的氯仿溶液中,并涂布于热解石墨电极表面,待氯仿挥发后制得NiPc-DDAB薄膜电极。循环伏安实验表明,在KBr溶液中,该薄膜电极有两对良好且稳定的还原氧化峰,第一对峰的Epc1=-0.64V,Epc1=—0.60V(vs.SCE);第二对峰的Epc2=—0.84V,Epc2=—0.80V,本文着重探讨了第二对峰的电化学行为,估计了该体系的电化学参数如电子扩散系数De和非均相电极反应速率常数k0'.该薄膜电极可用于催化各种卤代乙酸的电化学还原,用多种表面分析技术对该薄膜进行了表征。  相似文献   

5.
将酞菁锰(MnPc)掺入阳离子表面活性剂双十二烷基二甲基溴化铵(DDAB)的氯仿溶液,并涂布于热解石墨电极表面,待氯仿挥发后即制得MnPc-DDAB薄膜电极。循环伏安实验表明,在KBr溶液中,该薄膜电极有两对还原氧化峰,第一对峰的Epc1=-0.27V,Epa1=0.01V;第二对峰的Epc2=-0.76V,Epa2=-0.62V(vs.SCE)。本文着重探讨了第二对峰的电化学行为,估计了该体系的电荷传递扩散系数Dct和表观非均相电极反应速率常数K0′等电化学参数,并可将该薄膜电极用于催化三氯乙酸的电化学还原。  相似文献   

6.
NADH在邻苯二酚紫修饰石墨电极上的电催化氧化   总被引:2,自引:0,他引:2  
以吸附在石墨电极上的邻苯二酚紫作为电子传递媒介体构成修饰电极。在-0.40-+0.60V电位区间内,吸附态的邻苯二酚紫表现出相当可逆的氧化,还原行为,电极反应为单电子过程并有1个质子参加。在pH为7.0的磷酸盐缓冲溶液中,其式量电位E^o'为0.10V,表观电极反应速率常数ks为5.5s^-^1。邻苯二酚紫修饰电极对还原型烟酰胺腺嘌呤二核苷酸(NADH)的电化学氧化具有明显的催化作用。可使NADH  相似文献   

7.
将酞菁镍(NiPc)掺入阳离子表面活性剂双十二烷基二甲基溴化铵(DDAB)的氯仿溶液中,并涂布于热解石墨电极表面,待氯仿挥发后制得NiPc-DDAB薄膜电极。循环伏安实验表明,在KBr溶液中,该薄膜电极有两对良好且稳定的还原氧化峰,第一对峰的Epc1=-0.64V,Epal=-0.60V(vs.SCE);第二对峰的Epc2=-0.84V,Epa2=-0.80V。本文着重探讨了第二对峰的电化学行为,  相似文献   

8.
研究了聚色氨酸修饰玻碳电极(Poly-Try/GC)的制备,用循环伏安法探讨了膜的电化学性质。在pH=6.6的PBS中,膜的循环伏安图上有两对氧化还原峰。掺杂金属离子Ni(Ⅱ)后的该聚合物膜修饰电极(Poly-Ni(Ⅱ) Try/GC)对甲醇的催化活性大大提高,在0.01 mol/L NaOH中甲醇的氧化峰电位在0.65 V,而同样条件下在空白玻璃电极(GC)和Poly-Try/GC上甲醇的氧化峰电位要正得多。在0.15 mol/L甲醇溶液中循环伏安扫描150 min后,峰电流密度由1060 μA/cm~2降低至885μA/cm~2,然后峰电流密度不再降低,说明在电催化氧化甲醇过程中电极稳定性良好。  相似文献   

9.
将酞菁锰(MnPc)掺入阳离子表面活性剂双十二烷基二甲基溴化铵(DDAB)的氯仿溶液,并涂布于热解石墨电极表面,待氯仿挥发后即制得MnPc-DDAB薄膜电极,循环伏安实验表明,在KBr溶液中,该薄膜电极有两对还原氧化峰,第一对峰的Epct=-0.27V,Epa1=0.01V;第二对峰的Epc2=-0.76V,Epa2=-0.62V(vs.SCE)。本文着重探讨了第二对峰的电化学行为,估计了该体系电  相似文献   

10.
金在脱乙酰壳多糖学修饰电极上的电化学行为及分析应用   总被引:3,自引:1,他引:2  
用脱乙酰壳多糖化学修饰电极为工作电极,阳极溶出伏安法测定痕量金。在pH1 ̄2的KCl-HCl底液中,超始电位0.20V,终止电位1.30V,富集时间5min,以-0.1/s扫速阳极溶出,峰电位在1.00V(vs.SCE),Au(Ⅲ)浓度在0.10mg/L ̄10mg/L范围内与峰高呈线性关系。在富集10min时,可检测0.25mig/LAu,大大提高了测定灵敏度,用于矿样测定,无需分离,结果满意。用  相似文献   

11.
The influence of various factors such as solubility, the oxidation of the membrane, and the contamination of the solution, on the experimental values of the selectivity coefficients of solid state sulphide ion selective electrodes is discussed. A new method for the evaluation of very small selectivity coefficients, based on the addition of reagents forming complexes or insoluble salts with the main ion, is proposed. By means of this method, selectivity coefficients for silver, copper, cadmium and lead ion selective electrodes have been determined, which are in far better agreement with thermodynamic values than those described in the literature.  相似文献   

12.
维拉帕米选择性电极的研制和应用   总被引:3,自引:0,他引:3  
冷宗周  胡效亚 《分析化学》1991,19(11):1301-1304
  相似文献   

13.
用氧化还原聚合物修饰多孔电极   总被引:1,自引:0,他引:1  
对3种类型Nafion/Os(bpy)3Cl2修饰电极的研究结果表明,单位表观电极面积上中继体载量比为:乙炔黑粉末微电极(A):Teflon粘结的乙炔黑膜电极(B):平面玻碳电极(C)=10^3:10^2:1.A比B及C更容易在真实表面上形成花天酒地而均匀的修饰层而有利于层内的电荷传递。在A类电极基础上制行的葡萄糖酶电极在10mmol/L葡萄糖溶液中的响应电流密度高达4.6×10^-^4A/cm^  相似文献   

14.
陆克平  朱培德 《分析化学》2006,34(11):1661-1664
把玻璃参比电极、环状的银-硫化银指示电极、以及铂丝屏蔽电极组合形成新型硫醇硫组合电极,研究了在含有0.2 mol/L硫离子的醇-水-氨介质中,在表面活性剂存在下,以环状银电极为阳极,恒定微电流电沉积的方式制备硫化银敏感层的条件。由此法制得的新型硫醇硫组合电极在Ag 浓度为1.0×10-1~1.0×10-5mol/L范围内斜率为59.0±0.5 mV/pC,测量下限为2.2×10-6mol/L,与同类商品电极相比,响应速度快、记忆效应小、重复性好、电位稳定,易于批量生产,具有较强的适应性和应用价值。  相似文献   

15.
在N-Si和P-Si半导体上用化学沉积法制备了内场致发射电极并研究了它们的电化学行为。从分解电势Ⅰ~Ⅴ曲线可知,这种电极可在低于1.23V下分解水;对Fe~(3+)/Fe~(2+)体系的循环伏安图,其峰电流为铂电极的8倍多。  相似文献   

16.
Carbon nanotube, graphene and carbon black, as electrode modifiers, were compared and evaluated for the electrochemical determination of vancomycin. Among them, the best results were obtained at the graphene‐modified electrode. Additions of vancomycin using square wave voltammetry at the graphene‐modified electrode showed a linear range from 0.70 μM to 50 μM and a detection limit of 0.20 μM was obtained. To control the correct dose of vancomycin and reduce its side effects, its accurate determination in blood plasma is very important. Therefore, the method was applied for the vancomycin determination in spiked human plasma samples and satisfactory recoveries were observed. The developed method exhibited fast analysis, high sensitivity, good repeatability and freedom from other interfering species.  相似文献   

17.
A verapamil-PVC membrane ion-selective electrode based on the verapamil-reineckate ion pair was prepared with dibutyl phthalate as a plasticizer. The electrode exhibited a linear response with a Nernstian slope (52.8 mV decade?1 at 20° C) for verapamil concentrations of 10?5?10?2M over the pH range 3–7. The electrode also exhibited very good selectivity for verapamil with respect to various inorganic and organic cations. Gran II linear titration and potentiometric titration were used to determine verapamil in pure solution, with an average recovery of 99.3% and a relative standard deviation of 0.4%.  相似文献   

18.
《Analytical letters》2012,45(12):1457-1463
Abstract

Inexpensive, disposable, carbon-filled polymer paste reference electrodes are reported. These electrodes are designed for use in conjuction with carbon-filled polymer paste ion-selective probes reported earlier. Attachment of integrated electronics is easily achieved.  相似文献   

19.
Potentiometric electrodes were developed for the rapid determination of proguanil hydrochloride in pure samples, pharmaceutical preparations and spiked serum and urine samples using PVC membrane,screen printed(SPE), coated wired(CWE), carbon paste(CPE) and modified carbon paste(MCPE)electrodes based on the ion-exchanger of proguanil with phosphotungestic acid(Pr-PT) as a chemical modifier. The prepared electrodes showed Nernestian slopes of 59.7, 58.1, 58.5, 58.5 and 57.0 for the PVC,SPE, CWE, CPE and MCPE for the proguanil ions in a wide concentration range of 1.0 * 10~(-5)–1.0 * 10~(-2)mol L~(-1) at 25°C with detection limits of 7.94 * 10~(-6), 1.0 * 10~(-5), 1.0 * 10~(-6), 7.07 * 10~(-6) and 2.5 * 10~(-6) mol L~(-1), respectively. The prepared electrodes exhibited high proguanil selectivity in relation to several inorganic ions and sugars and they could be successfully utilized for its determination in pure solutions, pharmaceutical preparations and serum and urine samples using the direct potentiometry and standard addition methods with very good recovery values.  相似文献   

20.
在298K标准锌汞齐电极的标准电极电势   总被引:1,自引:0,他引:1  
饱和锌汞齐电极的标准电极电势,一般是指含锌量10%的锌汞齐电极对活度为1的锌离子所产生的电极电势,ε_(Zn~2+)~0+Zn-Hg(Zn10%)=—0.7618±0.0008V。固体金属锌电极的标准电极电势是指金属锌电极对活度为1的锌离子所产生的电极电势ε_(Zn~2+)~0-Zn=0.7618V。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号