伏安型植物组织生物微电极的研究——茄子组织碳糊微电极的研究

茄子组织生物微电极在儿茶酚测定中表现出了较高的生物催化活性,而对抗坏血酸测定则为稳态响应,这表明该电极能有效地消除抗坏血酸的干扰。该电极的灵敏度高,重现性好,对多巴胺测定的线性范围为5.8×10~(-6)～6.5×10~(-4)mol/L,检出下限为:2.9×10~(-6)mol/L。     

伏安型植物组织生物微电极的研究：混合不同植物组织碳糊微电极的研究

由于香蕉组织中含有的氧化酶能够生物催化氧化多巴胺，去甲肾上腺素，Ｌ－多巴等，大大地提高了植物组织电极的灵敏度；又由于茄子组织中所含有的氧化酶在催化氧化儿茶酚的同时，能有效地抑制抗坏血酸在电极上的反应，将上述两种植物组织混合制成电极，使其更适于神经递质的测定，线性范围：２．４×１０＾－６－－９．８×１０＾－４ｍｏｌ／Ｌ；检出下限３．２×１０＾－７ｍｏｌ／Ｌ。     

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.     

锂离子选择性微电极在生物体液中的响应

最近几年已报道了几种锂离子选择性电极.本文作者曾研制了以苯基膦酸二辛酯(DOPP)为溶剂,四苯硼酸盐为活性物质的PVC膜锂离子选择电极.本文在此基础上研制了锂离子选择性微电极,比较了以四苯硼酸钾(KTPB)及四苯硼酸钠(NaTPB)为活性物质的锂微电极的性能.同时考察了微电极在细胞内液、血清及生理盐液中对锂离子的响应特性.     

面向活体分析的核酸适体电化学生物传感研究

化学是生命活动的物质基础.在活体层次上精准获取生理活性分子的分布和含量的变化规律对于了解和研究生理和病理过程具有重要的意义.电化学方法,特别是基于核酸适体的电化学生物传感器,由于兼具高特异性识别、检测对象广以及易于微型化等优良特性,已成为复杂生理环境中实现快速、灵敏和高选择性检测的有效工具.本文综述了核酸适体电化学生物传感器的设计以及在活体分析中的应用,并对其未来发展趋势进行了展望.     

Mixed Plant Tissue-Carbon Paste Biomicroelectrode and Its Application to Determination of Dopamine in Vitro and in Vivo

Introduction A number of distinct voltammetric methods have been developed recently to determine the neurotransmission dopamine. For the techniques that are designed to measure dopamine, a major limitation is the inability to distinguish the oxidation peaks of dopamine from those of ascorbic acid. There is ascorbic acid throughout mammalian tissue, particularly higher (about 100 times of dopamine) in the     

土豆组织-碳糊电极的研制及应用

本文研制了土豆组织-碳糊电极,并探讨了电极的性能及实用性。实验表明,该电极可用于伏安法快速检测多巴胺。线性范围为5.3×10~(-8)～9.8×10~(-5)mol/L。检测下限达到1.8×10~(-6)mol/L。电极具有良好的重现性和选择性。响应时间短,使用寿命为20天。     

青椒籽浆-碳糊生物电极的研制及应用

本文研制了青椒籽浆-碳糊生物电极,并探讨了电极的性能及实用性,实验表明,该电极可用于伏安法快速检测L-抗坏血酸,线性范围为1.15×10~(-5)～1.24×10~(-4)mol/L,检测下限可达到9.87×10~(-6)mol/L,电极具有良好的重现性和选择性,响应时间短,使用寿命为12d。     

A Selective Voltammetric Method for Detecting Dopamine at Quercetin Modified Electrode Incorporating Graphene

The development of a quercetin‐graphene composite‐modified glassy carbon electrode (Qu/GH/GCE) for the selective and sensitive detection of dopamine (DA) is described in this paper. To fabricate the Qu/GH/GCE, graphene (GH) was first coated onto the surface of a glassy carbon electrode (GCE) and then quercetin (Qu) was electrodeposited on the GH matrix. Transmission electron microscopy (TEM) was used to characterize the morphology of the obtained GH and Qu/GH, and the electrochemical properties of the modified electrode were studied using electrochemical techniques. The as‐prepared Qu/GH/GCE occupied a synthetic property between GH and Qu. The common overlapped electrochemical oxidation peaks of DA and AA were completely separated and a remarkable increasing electron‐oxidation current of DA occurred on the Qu/GH/GCE, which enabled the sensitive and selective electrochemical detection of DA in the presence of ascorbic acid (AA) with peak difference of ca. 452 mV between DA and AA. The peak current obtained at 0.174 V (vs. saturated calomel electrode, SCE) from differential pulse voltammetry (DPV) is linearly dependent on the DA concentration in the range from 3.0×10^?8 to 4.0×10^?4 mol/L with a detection limit of 1.0×10^?8 mol/L. Furthermore, the Qu/GH/GCE exhibits good reproducibility and stability, and has been used for the determination of DA in samples of rat’s striatum tissue with satisfactory results.     

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。     

Fabrication of Fe3O4 Nanoparticles Modified Electrode and Its Application for Voltammetric Sensing of Dopamine

Magnetic nanoparticles of Fe₃O₄ approximately 5nm in size were synthesized and characterized by XRD and TEM. A novel gold electrode modified with Fe₃O₄ nanoparticles was then constructed and was characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The modified electrode exhibited strong promoting effect and high stability toward the electrochemical oxidation of dopamine (DA), which gave reversible redox peaks with a formal potential of 0.192 V (vs. Ag/AgCl) electrode in pH 7.0 phosphate buffer solution (PB). The anodic peak currents (measured by constant potential amperometry) increased linearly with the concentration of dopamine in the range of 1.5×10^?7 to 4.0×10^?4 M. The detection limit (S/N=3) obtained was 3.0×10^?8 M. The relative standard deviation (RSD) of 8 successive scans was 3.41% for 1.5×10^?6 M DA. The interference of ascorbic acid (AA) could be eliminated efficiently. The proposed method showed excellent sensitivity and recovery.     

多巴胺和抗坏血酸在CPB现场修饰碳糊电极上的电化学及电化学动力学性质

用现场修饰方法制备了溴化十六烷基吡啶(CPB)修饰碳糊电极(CPB/CPE)。运用循环伏安法(cyclic voltammetry,CV)、电位阶跃计时电流法(chronoamperometry,CA)及电位阶跃计时库仑法(chronocoulometry,CC)法研究了多巴胺(DA)和抗坏血酸(AA)在裸碳糊(CPE)和CPB/CPE上的电化学行为,测得了动力学参数如电荷转移系数α,扩散系数D,反应级数和电极反应速率常数kf。研究结果表明CPB/CPE可用于AA和DA共存体系中DA的电化学选择性测定。     

Enhanced Electrochemiluminescence of TiO2 Nanoparticles Modified Electrode by Nafion Film and Its Application in Selective Detection of Dopamine

In this work, a simple and effective approach to obtain stable, nontoxic and strong electrochemiluminescence (ECL) interfaces is provided by coating TiO₂ nanoparticles (NPs) modified glassy carbon electrode (GCE) surfaces with Nafion. Unlike a decrease of the current resulting from the blocked diffusion usually displayed in electrochemical processes by Nafion coating, a Nafion/TiO₂ NPs modified electrode not only shows a highly stable ECL, but also shows an 8‐fold increase of ECL intensity and a reduction of the overpotential of ca. 300 mV in the presence of K₂S₂O₈ as co‐reactant, compared with those of bare TiO₂ NPs modified electrodes. The roles of Nafion coating on TiO₂ NPs in the ECL process are proposed to be twofold: to provide refuge for the free radicals and to enhance the electron‐hole recombination. Benefiting from its excellent ECL performance, the cationic exchange function of Nafion and the susceptible to being oxidized performance of dopamine (DA) by holes, the Nafion/TiO₂ composite electrode could be used to sensitively and selectively detect DA with a detection limit of 1.0×10^?11 M and a linear range of 1.0×10^?11–6.0×10^?7 M. The coexisting anionic species such as excess ascorbic acid show little interference on DA detection.     

银掺杂聚L-天冬氨酸修饰电极的制备及对多巴胺的测定

利用循环伏安法将银与L-天冬氨酸聚合修饰在玻碳电极表面,制成银掺杂聚L-天冬氨酸修饰电极,研究了多巴胺在此电极上的电化学行为,建立了循环伏安法测定多巴胺的新方法.在磷酸盐缓冲溶液(PBS, pH 7.0)中,扫描速率为50 mV/s时,多巴胺在修饰电极上产生一对氧化还原峰,Epa=0.191 V,Epc=0.161 V.用循环伏安法进行测定时,峰电流与多巴胺浓度分别在3.0×10-7 ～1.0×10-5 mol/L和1.0×10-5 ～5.0×10-4 mol/L内呈良好的线性关系; 检出限为5.0×10-8 mol/L.用于药物和尿样中多巴胺的测定,结果满意.