丝氨酸织组膜电极的研究

利用猪肝组织膜配合氨气敏电极,研制了丝氨酸生物催化传感电极。丝氨酸浓度的测定范围为5.1×10~(-5)～3.2×10~(-3)mol/L,检出限为3.1×10~(-5)mol/L。研究和讨论了电极的最佳工作条件,并测定了实验条件下酶催化反应的米氏常数Km。该电极用于合成样品分析,效果满意。     

基于尼古丁对胆碱氧化酶的抑制作用测定尼古丁的研究

基于尼古丁对胆碱氧化酶(CHOD)的抑制作用,将胆碱氧化酶电极用于微量尼古丁的测定。酶电极制作中,先在铂电极表面修饰一层壳聚糖膜,再用戊二醛交联CHOD。采用这种酶固定化方法,电极在4. 0×10-6 ~ 3×10-3 mol/L胆碱的浓度范围呈线性关系。探讨了工作电位、pH、底物浓度等实验条件对酶电极性能及抑制过程中响应电流的影响,测定了电极的重现性、干扰及使用寿命。电极检测尼古丁的线性范围为1. 5×10-5 ~3×10-3 mol/L;检出限为1. 25×10-5 mol/L。将电极用于实际样品烟草中尼古丁回收率的测定,结果良好。     

Eastman-Kodak AQ膜修饰电极阴极溶出伏安法测定痕量铁

本文用热处理法成功地制备了性能稳定的Eastman-Kodak AQ/GC修饰电极,对Fe~(3+)/Fe~(2+)及其络合阳离子在该电极上的行为进行了研究。表明AQ膜对Fe~(3+)和Fe~(2+)具有相近的交换能力,可用于Fe~(3+)或Fe~(2+)及其总量的阴极溶出伏安法测定。线性范围分别为2.0×10~(-7)～2.2×10~(-5)mol/L(Fe~(3+))和5.0×10~(-7)～2.0×10~(-5)mol/L(Fe~(2+)),检出限为1.0×10~(-7)mol/L(Fe~(3+))。文中对电极反应和再生进行了探讨。     

以聚氯乙烯-双硫腙-铜络合物为载体的长寿命硫氰酸根离子选择电极

报道了以PVG-双硫腙（DTZ）-Cu（Ⅱ）,PVC-DTZ-Cu（Ⅰ）为载体制备了性能良好的SCN-离子电极,其选择性次序为SCN~-》ClO_4~->Sal~-》NO_3~-~Cl~->PO_4~(2-)。16℃时,膜组成为PVC－DTZ-Cu（Ⅰ）：PVC：邻硝基苯基辛醚（o-NPOE）＝12∶22∶66的SCN~-离子电极,在0．02mol/LHCl体系中,在1×10~(-2)~5×10~(－6)mol/LSCN~-浓度范围呈能斯特响应,斜率为58±2mV/dec,检测限为2×10~(-6)mol/L;膜组成为PVC-DTZ-Cu（Ⅱ）∶PVC∶o-NPOE∶四苯硼酸钾（KTPB）为8∶22∶55∶15的电极,在0．01mol/LHAc-NaAc缓冲体系中,在10~(-2)~2×10~(-6)mol/LSCN~-浓度范围呈线性响应,斜率为54∶1mV/dec,检测限为8×10~(－7)mol/L.研究了阴离子与载体作用的机理,表明SCN~-与载体中铜原子直接作用。电极应用于废水中SCN~-的测定,结果令人满意。     

5—羟色胺敏感膜电极的研究 Ⅰ.离子缔合型5—羟色胺膜电极的研制

5-羟色胺(5-HT)与许多疾病的发生和发展有关。应用正交试验,研究了离子缔合型5-HT敏感膜电极的最优化膜组成。筛选了由3种定域体,7种增塑剂组成的213个配方,选定了以四苯硼-5-HT离子缔合物为活性物、磷酸三(2-乙基己基)酯为增塑剂的涂碳PVC膜电极。电极各项性能良好,其线性范围为1.00×10~(-2)～1.58×10~(-5)mol/L,检测下限为4.17×10~(-6)mol/L,斜率为59.7mV/p5-HT。电极寿命超过39天,用混合溶液法测定了体液中可能存在的17种物质的选择性系数。已用该电极测定了牛血小板中的5-HT。     

酚类化合物在二氧化锡微粒修饰碳纤维电极上的氧化及检测

采用金属有机化学气相沉积技术制备了SnO2 修饰碳纤维微柱电极 ,讨论了电极的表面结构和稳定性 ,并利用循环伏安法分析了酚类化合物在电极上的电化学行为。该电极对酚类化合物有明显的电催化活性 ,并能防止酚类物质在碳纤维电极表面的电聚合。以 3 氯苯酚为测试物 ,其检测的线性浓度范围为 2× 10 -6～ 1.2× 10 -5mol/L     

Nafion-甲基紫精修饰电极抗坏血酸氧化酶生物传感器的研究

本文用Nafion-甲基紫精修饰电极为基底,以牛血清白蛋白和戊二醛为交联剂,将抗坏血酸氧化酶固定在电极上,制成修饰电极抗坏血酸氧化酶生物传感器。用这种生物传感器测定人体血清中抗坏血酸,线性范围在7.5×10~(-4)～7.5×10~(-7)mol/L之间,响应时间为5s,检测下限为2.5×10~(-7)mol/L。该传感器具有选择性好、灵敏度高和响应时间短等特点。     

菠菜组织微电极的研制及其对神经递质多巴胺在体测定的可行性研究

菠菜组织微电极是一种新型的酶电极。应用该电极测定神经递质多巴胺(DA)时表现出较高的灵敏度和较好的选择性,它能够有效地消除抗坏血酸(AA)的干扰。其线性范围为1.7×10~(-6)～1.6×10~(-4)mol/L,检出下限为7.1×10~(-7)mol/L。对其在体测定DA的可行性研究,表明它是一种能够用于在体测神经递质的微电极。     

聚氯乙烯膜依诺沙星选择电极的研制与应用

以盐酸依诺沙星与四苯硼酸盐生成的分子缔合物制成新型PVC膜依诺沙星选择电极,应用于依诺沙星药片的含量测定。在pH 2.2～6.5范围内,电极的能斯特响应范围为5.0×10~(-5)～1.0×10~(-2)mol/L,斜率为58.0mV/pc,检出限为4.2×10~(-6)mol/L。该电极响应速度快,重现性好。3次测定的平均回收率为97.5％,RSD为1.0％,结果与紫外分光光度法基本一致。     

谷氨酸脱羧酶电极与大肠杆菌膜电极的比较研究

本文研究了分别用谷氨酸脱羧酶和大肠杆菌作为催化L-谷氨酸脱羧的酶材料来制作的生物传感器的响应性能。结果表明这两种电极各具特点。谷氨酸脱羧酶电极对底物L-谷氨酸的校正曲线的线性范围为3.16×10~(-4)mol/L～1.0×10~(-2)mol/L。斜率为46mV,响应时间为6～8min电极寿命仅为5天。而大肠杆菌膜电极线性范围为4.22×10~(-4)mol/L～1.78×10~(-2)mol/L,斜率为48.5mV,响应时间为8～9min,电极寿命达34天。这两种电极对底物L-谷氨酸皆具有专一的选择性,且在磷酸吡哆醛的存在下,活性都有所增加。将电极用于味精中L-谷氨酸钠的测定,获得较满意的结果。     

Side effects in measurements of selectivity coefficients of solid state ion selective electrodes

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.     

用氧化还原聚合物修饰多孔电极

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＾     

新型硫醇硫组合电极研制及性能测试

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。     

内场致发射电极的电化学行为

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。     

Electroanalytical Determination of Vancomycin at a Graphene‐modified Electrode: Comparison of Electrochemical Property between Graphene,Carbon Nanotube,and Carbon Black

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.     

Carbon-Filled Polymer Paste Reference Electrodes

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.     

Poly(vinyl chloride) membrane electrode for the determination of verapamil

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%.     

Development of new potentiometric sensors for the determination of proguanil hydrochloride in serum and urine

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.