蒙脱土修饰碳纤维电极的制备及其应用于活体测定脑神经递质

Construction of Montmorillonite-modified Carbon Fiber Electrode and ItsIn-vivo Detection of Neurotransmitter

制备了蒙脱土修饰碳纤维电极 ,研究了其对神经递质多巴胺 (DA)及 5 羟色胺 (5 HT)的富集作用 ,以及对负电性的代谢产物 3 ,4 二羟基苯乙酸 (DOPAC)、 5 羟吲哚乙酸 (5 HIAA)及脑内大量存在的抗坏血酸(AA)排斥性能 .该电极具有很高的灵敏度、分辨率和抗干扰性 ,对DA的检测下限达 1 6× 10 -8mol/L ,优于传统的Nafion修饰电极 ,对 5 HT的检测下限为 1× 10 -7mol/L .在动物活体分析中 ,使用该电极成功地检测了大鼠双侧颈总动脉结扎 再灌损伤时 ,脑纹状体中神经递质DA浓度的变化 .

The construction of montmorillonite-modified carbon fiber electrode is reported. The modified electrode shows a good sensitivity and selectivity due to its accumulation to cations and inhabitation to anions. The detection limit of DA and 5-HT are 1 6×10^-8 and 1×10^-7 mol/L, respectively, which are more sensitive than Nafion modified electrode.In-vivo voltammetry, the electrode has directly detected the dramatic variation of DA concentration in a rat brain with decreasing blood supply, while it effectively inhabits the oxidation of electroactive compounds and some neurotransmitter metabolites, such as AA, DOPAC, 5-HIAA.