三维纳米枝状物表面制备蛋白质印迹聚合物及其性能

在金电极表面制备了3D金/铜纳米枝状物,并以丙烯酰胺为功能单体,N,N-亚甲基双丙烯酰胺为交联剂,血红蛋白为模板分子,在枝状物表面成功制备了蛋白质印迹聚合物。利用循环伏安法和扫描电子显微镜对制备的聚合物修饰电极进行了表征,通过微分脉冲伏安法、利用制备的聚合物修饰电极可对溶液中的血红蛋白进行检测,得到比已报道的类似印迹传感器更宽的检测范围和更低的检测下限,其线性范围为1.0×10~(-14)~1.0×10~(-1)mg/L,检测限为1.9×10~(-15)mg/L(S/N=3),相关系数为0.9975。实验结果表明,在电极表面制备的金/铜纳米枝状物,大大提高了电极的电子传递能力,也提高了印迹聚合物修饰电极的检测范围。     

聚茜素红膜修饰电极控制电位扫描法分别测定多巴胺和抗坏血酸

研究了聚茜素红膜修饰电极(PARE)的制备及其对多巴胺(DA)和抗坏血酸(AA)的电催化性能,结果表明,在PARE上DA和AA具有不同的循环伏安行为,前者表现为一个准可逆过程,后者则为不可逆过程,并且二者的氧化峰电位分开近200mV.因此可通过控制不同的电位范围进行分步扫描,实现了对同一体系中DA和AA的分别测定,DA的还原峰电流和AA的氧化峰电流分别在8.0×10^-6～4.0×10^-3mol/L和4.0×10^-5～2.0×10^-2mol/L范围内与各自的浓度呈线性关系;检测限分别为8.0×10^-7mol/L和1.0×10^-5mol/L.同时与导数伏安法一步测定进行比较,结果令人满意.     

金纳米粒子/聚多巴胺/碳纳米管修饰玻碳电极对核黄素的测定

采用原位还原法制备金纳米粒子/聚多巴胺/碳纳米管（Au-PDA-MWNTs）复合材料,并将其用于建立高灵敏检测核黄素的电化学方法.采用紫外–可见光谱、扫描电镜、x-射线能谱对Au-PDA-MWNTs复合材料进行表征,采用循环伏安法和差示脉冲伏安法探讨核黄素（RF）在Au-PDA-MWNTs修饰的玻碳电极上的电化学行为,并对RF含量进行测定.该方法对核黄素的检测在5×10^-9 mol·L^-1～1×10^-5 mol·L^-1的范围内呈良好的线性关系（R=0.9906）,检测限为1.7×10^-9 mol·L^-1.本方法操作简便、抗干扰能力强,方法可行,因此该方法成功实现了维生素药片中RF含量的测定.     

阴离子交换膜修饰的水/1,2-二氯乙烷界面上SO42-离子的转移反应

将一种均相季铵型阴离子交换膜用于修饰水/1,2-二氯乙烷(W/DCE)界面,并利用循环伏安法、差分脉冲伏安法和计时电量法考察了该界面上强亲水性阴离子SO₄^2-的转移反应过程.研究结果表明,该阴离子交换膜所修饰的W/DCE界面比修饰前具有更宽的电化学窗口,而且在界面上可获得完整的SO₄^2-转移的循环伏安曲线和差分脉冲伏安曲线.其中,循环伏安曲线的峰电流与扫速平方根呈线性关系,SO₄^2-在膜内水相中的扩散系数为7.6×10^-8 cm²/s;差分脉冲伏安曲线的峰电流与SO₄^2-的浓度在5~25 mmol/L范围内呈线性关系.另外,利用计时电量法测得SO₄^2-在该界面上转移反应的标准速率常数为1.49×10^-3 cm/s.     

石墨烯修饰玻碳电极在对苯二酚存在下选择性测定米吐尔

制备了石墨烯修饰玻碳电极(GN/GCE)。 在0.5 mol/L HAc-NaAc(pH=4.8)缓冲溶液中,用循环伏安法(CV)和方波伏安法(SWV)研究了米吐尔在修饰电极上的电化学行为,建立了测定米吐尔的新方法。 研究表明,米吐尔在GN/GCE上的氧化、还原峰电势差比其在裸玻碳电极(GCE)上的小,峰电流显著增加,说明GN/GCE对米吐尔有电催化作用;共存物对苯二酚干扰米吐尔的测定,通过方波伏安法可以消除其干扰。 在方波伏安曲线上,米吐尔的还原峰电流与其浓度在8.0×10^-8~5.0×10^-5 mol/L范围内呈线性关系,检出限为2.0×10^-8 mol/L。 该法可用于照相显影废液中米吐尔的测定。     

Investigations of Thallium(Ⅰ) Underpotential Deposition on the Silver Rotating Disk Electrode and Its Analytical Application

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Electrocatalytic Oxidation and Simultaneous Determination of Uric Acid,Xanthine, Hypoxanthine and Dopamine Based on β-Cyclodextrin Modified Glassy Carbon Electrode

A novel covalently modified glassy carbon electrode with β-cyclodextrin was prepared via electropolymerization technique for the simultaneous determination of uric acid(UA), xanthine(XA), hypoxanthine(HX) and dopamine(DA). This new electrode presented an excellent electrocatalytic activity towards the oxidation of UA, XA, HX and DA by cyclic voltammetry(CV) method. The oxidation peaks of the four compounds were well defined and had the enhanced peak currents. The separation potentials of the oxidation peaks for DA-UA, UA-XA and XA-HX were 150, 390 and 360 mV in CV, respectively. By means of differential pulse voltammetry(DPV) method, the calibration curves in the ranges of 10-225, 5-105, 10-170 and 5-150 μmol/L were obtained for UA, XA, HX and DA, respectively. The lowest detection limits(S/N=3) were 5, 1.25, 5 and 1.5 μmol/L for UA, XA, HX and DA, respectively. The practical application of the modified electrode was demonstrated by the determination of DA in hydrochloride injection and UA, XA, HX in human urine samples.     

自组装膜上细胞色素c的电化学石英晶体微天平实时表征和定量检测

采用电化学石英晶体微天平(EQCM)实时表征和定量检测细胞色素c(Cytc).在压电石英晶振表面上自组装巯基十一酸(MUA)单层膜,以盐酸1-乙基-3-(3-二甲基氨基丙基)碳二亚胺(EDC)和N-羟基琥珀酰亚胺(NHS)活化羧基,将Cytc共价固化到电极表面.EQCM实时监测了MUA的自组装和Cytc的固化过程,测定了二者在电极表面的覆盖度和Cytc的固化量.结果表明,Cytc在0.03～3.00μmol/L浓度范围内呈线性变化,检测限可达到1.19×10^-9mol/L.     

Electrochemical Study and Application on Shikonin at Poly(diallyldimethylammonium chloride) Functionalized Graphene Sheets Modified Glass Carbon Electrode

The electrochemical behaviors of shikonin at a poly(diallyldimethylammonium chloride) functionalized graphene sheets modified glass carbon electrode(PDDA-GS/GCE) have been investigated. Shikonin could exhibit a pair of well-defined redox peaks at the PDDA-GS/GCE located at 0.681 V(E_pa) and 0.662 V(E_pc)[vs. saturated calomel electrode(SCE)] in 0.1 mol/L phosphate buffer solution(pH=2.0) with a peak-to-peak separation of about 20 mV, revealing a fast electron-transfer process. Moreover, the current response was remarkably increased at PDDA-GS/GCE compared with that at the bare GCE. The electrochemical behaviors of shikonin at the modified electrode were investigated. And the results indicate that the reaction involves the transfer of two electrons, accompanied by two protons and the electrochemical process is a diffusional-controlled electrode process. The electrochemical parameters of shikonin at the modified electrode, the electron-transfer coefficient(α), the electron-transfer number(n) and the electrode reaction rate constant(k_s) were calculated to be as 0.53, 2.18 and 3.6 s^-1, respectively. Under the optimal conditions, the peak current of differential pulse voltammetry(DPV) increased linearly with the shikonin concentration in a range from 9.472×10^-8 mol/L to 3.789×10^-6 mol/L with a detection limit of 3.157×10^-8 mol/L. The linear regression equation was I_p=0.7366c+0.7855(R=0.9978; I_p: 10^-7 A, c: 10^-8 mol/L). In addition, the modified glass carbon electrode also exhibited good stability, selectivity and acceptable reproducibility that could be used for the sensitive, simple and rapid determination of shikonin in real samples. Therefore, the present work offers a new way to broaden the analytical application of graphene in pharmaceutical analysis.     

高压液相色谱磷钼杂多酸修饰电极安培检测儿茶酚胺类神经递质的研究

研究了磷钼杂多酸修饰电极对去甲肾上腺素(NE)、肾上腺素(E)和多巴胺(DA)等儿茶酚胺类神经递质的催化氧化作用,探讨了催化机理,并采用高压液相色谱电化学方法对其进行了分离检测,NE、DA和E的线性范围(mol)依次为8.0×10^-11～2.0×10^-8、8.0×10^-11～2.0×10^-8、4.0×10^-11～2.0×10^-8;检测限(mol))依次为4.0×10^-11、4.0×10^-11、2.0×10^-11.7次平行测定的相对标准偏差(％)依次为1.6、2.0和4.5.将此法用于鼠脑组织中神经递质的测定,获得满意的结果.     

纳米氧化铜修饰的苯巴比妥分子印迹传感器的制备及其电化学性能

为了改善分子印迹传感器的灵敏度,在四丁基高氯酸铵的支持电解质溶液中,以甲基丙烯酸为功能单体,马来松香丙烯酸乙二醇酯为交联剂在纳米氧化铜修饰过的玻碳电极上电聚合了一种苯巴比妥(PB)识别性能的分子印迹传感膜.采用循环伏安(CV)法、差分脉冲伏安(DPV)法及交流阻抗(EIS)法对这种纳米氧化铜修饰过的印迹及非印迹电极的电化学性能进行了研究,结果显示纳米氧化铜修饰过的印迹及非印迹电极的电化学性能完全不同.X射线衍射(XRD)证实纳米粒子为氧化铜.采用扫描电镜(SEM)对纳米氧化铜修饰过的印迹传感器的形貌进行分析,发现纳米氧化铜分散在电极表面,改善了修饰印迹传感器的识别点.差分脉冲伏安法(DPV)表明苯巴比妥的浓度在1.0×10-8-1.8×10-4mol·L-1范围内呈现良好的线性关系(线性相关系数R=0.9994);检出限2.3×10-9mol·L-1(信噪比(S/N)=3).研究结果表明纳米氧化铜修饰过的印迹传感器具有较高灵敏度及选择性.此印迹传感器能用于实际样品中苯巴比妥的检测,加标回收率在95.0%-102.5%.     

单壁碳纳米管修饰的高灵敏纳米碳纤维电极

碳纳米管已被应用于电极材料,但未得到良好的电化学伏安行为;且由于碳纳米管的直径很小(几到数十纳米),制作单根的碳纳米管电极非常困难,难以实际应用.碳纳米管用于修饰电极已得到更多重视,但都在常规尺寸(毫米级)的电极上进行,这样的电极不适于在生物微环境和毛细管电泳电化学检测中应用.     

双柱碳纤维微电极的研究及其在测定多巴胺中的应用

报道了双柱微电极的制作方法,提出了用双柱碳纤维微电极在抗坏血酸存在下选择性地测定多巴胺.探讨了电极反应机理.多巴胺的浓度在5.0×10^-4～5.0×10^-6mol/L范围内与收集电流成正比.抗坏血酸浓度<5.0×10^-4mol/L时对测定结果无影响.     

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.     

Electrochemical Behavior of Mitoxantrone and Its Determination at a Pt／C Implanted Modified Microelectrode

In a 0.02 mol/L Na2HPO4-KH2PO4(PBS) buffer solution(pH=6.82), the electrochemical behavior of mitoxantrone was studied by linear-sweep voltammetry and cyclic voltammetry at a Pt/C ion implantation modified microelectrode. A sensitive reduction peak was observed. The peak potential was -0.72 V(vs.SCE), the peak current was proportional to the concentration of mitoxantrone within the ranges of 7.0×10-8-9.0×10-7 mol/L and 1.0×10-6-2.4×10-5 mol/L, with a detection limit of 4.0×10-8 mol/L. The linear correlation coefficients were 0.9994 and 0.9992, respectively. This method has been applied to the direct determination of mitoxantrone in simulated urine. The recoveries were in the range from 96.2% to 105.9%. The reduction process was a quasi-reversible one with adsorptive characteristics at the Pt/C microelectrode. The electrode reaction rate constant ks and the electron transfer coefficient α of the system were determined to be 4.5 and 0.65 s-1, respectively. The experiments showed that Pt element had surely been implanted into the surface of the carbon fiber, and the atomic Pt improved the electrocatalytic activity. The Pt/C microelectrode had a good stability and reproducibility.     

基于Nafion固定磷钼酸和石墨烯共修饰PEDOT膜电极的电化学过氧化氢传感器

以玻碳电极（GCE）为基底电化学聚合制得聚3,4-乙烯二氧噻吩（PEDOT）膜修饰电极,再通过Nafion共固定磷钼酸和石墨烯构建了一种新型的无酶电化学H₂O₂传感器. 利用扫描电子显微镜（SEM）表征制得的修饰电极,并通过循环伏安法和计时电流法研究了传感器对H₂O₂的响应性能. 结果表明,在优化条件下,该传感器对H₂O₂还原具有良好的电催化性能,检测H₂O₂的线性范围为2.91×10^-6 ~ 1.83×10^-2 mol•L^-1,检出限和灵敏度分别为9.90×10^-7 mol•L^-1（S/N = 3）和112.5 μA•（mmol•L^-1）^-1. 此外,该传感器还具有良好的重现性和选择性.     

Studies on the Voltammetric Behavior of Nicardipine Hydrochloride,its Voltammetric Determination at the Co/GC Modified Electrode

To whom correspondence should be addressed. In a 0.02 mol/L BR buffer solution(pH=5.52), the electrochemical behaviour of nicardipine hydrochloride was studied by linearsweep voltammetry, cyclic voltammetry at a Co/GC ion implantation modified electrode. The experiments showed that the electrode had a good stability, reproductivity. The peak height was proportional to the concentration of nicardipine over the range of 4.0×10^-7—1.0×10^-4 mol/L, the detection limit was 1.0×10^-7 mol/L. This method has been used for the direct determination of nicardipine in tablets. Its recoveries were in the range from 95.6% to 103.8%. The reduction of nicardipine at the Co/GC electrode was an irreversible proccess.     

硫酸特布他林在聚铬黑T修饰电极上的电化学行为及其测定

采用电化学聚合法制备了聚铬黑T膜修饰电极,应用扫描电镜、交流阻抗法和循环伏安法对修饰电极进行表征,以循环伏安法研究硫酸特布他林在修饰电极上的电化学行为,并以差示脉冲伏安法对其含量进行测定.该方法对硫酸特布他林有明显的电催化作用,在pH 7.0磷酸盐缓冲液中,氧化峰电流与硫酸特布他林浓度在1.2x10^-7~2.0x10^-6mol•L^-1范围内呈良好的线性关系,检测限为1.5x10^-8 mol•L^-1,回收率在97.9%～104.6%之间,RSD在2.8 % (C=8x10^-7mol•L^-1,n=11).该方法简便灵敏,结果准确可靠,方法重复性好,可用于硫酸特布他林及其片剂的质量控制.     

Electroanalysis and simultaneous determination of dopamine and epinephrine at poly(isonicotinic acid)-modified carbon paste electrode in the presence of ascorbic acid

A carbon paste electrode modified with electropolymerized fills of isonicotinic acid was developed.The modified electrode shows excellent electrocatalytic activity toward the oxidation of both dopamine(DA)and epinephrine(EP).Separation of the reduction peak potentials for dopamine and epinephrine was about 357 mV in pH 5.3 phosphate buffer solution(PBS)and the character was used for the detection DA and EP simultaneously.The peak currents increase linearly with DA and EP concentration over the range of 8.0×10-5 to 7.0×10-4 mol/L and 5.0×10-6 to 1.0×10-4 mol/L with detection limits of 2 × 10-5 and 1×10-6 mol/L,respectively.The interference studies showed that the modified electrode exhibits excellent selectivity in the presence of large excess of ascorbic acid(AA).     

Keggin 型磷钨酸盐修饰碳糊电极传感多巴胺的研究

多金属氧酸盐作为一类阴离子簇合物,由于其结构的多样性和尺寸大小的可调变性,在电化学、催化和药学等领域引起了人们的广泛关注.本文制备了多酸Co(C₁₅N₆H₁₂)₂[PW₁₂O₃₈]·5H₂O（Co[PW₁₂O₃₈]）修饰碳糊电极并通过电化学阻抗谱、循环伏安法以及差分脉冲伏安法对多巴胺的传感性能进行了研究.对其制备条件和检测条件分别进行了优化.在优化条件下,制备的传感器对多巴胺具有良好的选择性和灵敏度的检测能力.多巴胺的线性响应范围为8.0x10^-6 mol·L^-1至3x10^-5 mol·L^-1,灵敏度为0.039 μA·(μmol·L^-1)^-1,检出限（S/N=3）为5.4 x10^-6 mol·L^-1. 制备的多酸修饰碳糊电极用于检测多巴胺表现出良好的稳定性和重现性,并且对抗坏血酸、尿酸等常见的干扰物质,具有良好的抗干扰性. 多酸修饰的碳糊电极制备过程简单方便,成本低,传感性能良好,对应用于电化学传感器检测多巴胺具备潜在的应用前景.