电化学活化碳纤维微电极和脑神经递质及抗坏血酸在体测定  

Electrochemical Activation of Carbon Fiber Microelectrodes for in vivo Determination of Neurotransmitters and Ascorbic Acid

作　　者：彭图治[1] 王国顺[1] 沈报恩[1] 刘国卿[2] 曹于平[2] 

机构地区：[1]杭州大学化学系,杭州310028 [2]中国药科大学药学系,南京210009

出　　处：《化学学报》1993年第8期804-810,共7页Acta Chimica Sinica

基　　金：国家和浙江省自然科学基金

摘　　要：本文采用一种简单电化学方法,即恒电流法处理自制碳纤维电极,在脑神经递质测定中显示了很高的灵敏度和分辨能力.活化后的电极对多巴胺的检测限达5×10^(-8) mol·dm^(-3),对多巴胺和抗坏血酸的伏安峰分离达170mV.作者使用该电极,采用半微分伏安法测定了活体大鼠脑内抗坏血酸,3,4-二羟苯乙酸和5-羟吲哚乙酸的浓度分别为1.7×10^(-4),2.1×10^(-5)和3.3×10^(-6)mol·dm^(-3).本文对电极的制作,活化条件,伏安峰判别,在体药物实验和电极活化机理等进行了研究和探讨.A new procedure of electrochemical activation for carbon fiber microelectrodes was reported. The treatment was simple, at first a constant current of 30 μA for 30 s, and then a potential of -2.0 V for 10s were applied to the electrode. After activation, the pretreated electrode showed very high sensitivity and seletivity. The detection limit of 5×10^(-8)mol·dm^(-3) for dopamine (DA) in phosphate buffer solution (pH 7.4) was found. The potential deviation of ascorbic acid (AA) peak from DA peak was 170 mV. The semi-differential voltammetry was used for in vivo determination in the rat brain. Three peaks at+0.01, +0.18 and+0.35 V were recognized as ascorbic acid, 3, 4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindoleacetic acid (5-HIAA), and their concentrations were 1.7×10^(-4), 2.1×10^(-5) and 3.3×10^(-6)mol·dm^(-3) respectively. The effect of the antihypertensive drug reserpine on DOPAC and 5-HIAA was observed. The mechanism of activation for carbon fiber electrodes was explored. It was possible that the surface oxidation of electrodes enhanced the sensitivity and further reduction improved the selectivity.

关 键 词：碳纤维微电极 脑神经递质 抗坏血酸 

分 类 号：R446.9[医药卫生—诊断学]