Xu Jiming, Wang Yanping, Xian Yuezhong, Jin Litong, Tanaka K
Department of Chemistry, East China Normal University, Shanghai, China.
Talanta. 2003 Aug 29;60(6):1123-30. doi: 10.1016/S0039-9140(03)00214-5.
A multiwall carbon nanotubes (MWNTs) film modified electrode was prepared and used as an amperometric sensor for the simultaneous determination of oxidizable amino acids including cysteine, tryptophane and tyrosine. The electrochemical behaviors of these amino acids at this modified electrode were studied by cyclic voltammetry (CV). The results indicated that the MWNTs chemically modified electrode (CME) exhibited efficient electrocatalytic activity towards the oxidation of these amino acids with relatively high sensitivity, stability and long-life. Following separation by ion chromatography (IC) with 2.0 x 10(-3) mol l(-1) citric acid buffer solution (pH 6.5) as eluent, cysteine, tryptophane and tyrosine could be determined by the MWNTs CME successfully. Under the optimal conditions, the detection limits were 7.0 x 10(-7) mol l(-1) for cysteine, 2.0 x 10(-7) mol l(-1) for tryptophane and 3.5 x 10(-7) mol l(-1) for tyrosine at the signal-to-noise of 3, respectively. The method was applied successfully to the determination of these substances in plasma.
制备了一种多壁碳纳米管（MWNTs）薄膜修饰电极，并将其用作安培传感器，用于同时测定包括半胱氨酸、色氨酸和酪氨酸在内的可氧化氨基酸。采用循环伏安法（CV）研究了这些氨基酸在该修饰电极上的电化学行为。结果表明，MWNTs化学修饰电极（CME）对这些氨基酸的氧化表现出高效的电催化活性，具有较高的灵敏度、稳定性和长寿命。以2.0×10⁻³ mol L⁻¹柠檬酸缓冲溶液（pH 6.5）为洗脱剂，通过离子色谱（IC）分离后，MWNTs CME可成功测定半胱氨酸、色氨酸和酪氨酸。在最佳条件下，半胱氨酸、色氨酸和酪氨酸在信噪比为3时的检测限分别为7.0×10⁻⁷ mol L⁻¹、2.0×10⁻⁷ mol L⁻¹和3.5×10⁻⁷ mol L⁻¹。该方法已成功应用于血浆中这些物质的测定。
