Nafion/multi-wall carbon nanotubes composite film coated glassy carbon electrode for sensitive determination of caffeine
Nafion/multi-wall carbon nanotubes composite film coated glassy carbon electrode for sensitive determination of caffeine
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DOI：
10.1016/j.jelechem.2009.11.025
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发表时间：
2010-02-15
影响因子：
4.5
通讯作者：
Yu, Lanlan
中科院分区：
文献类型：
--
作者：
Yang, Suling;Yang, Ran;Yu, Lanlan
制备了Nafion/多壁碳纳米管（MWNTs）复合膜修饰电极，并将其用于咖啡因的测定。在0.1%的Nafion存在下，多壁碳纳米管（MWNTs）易于通过超声分散均匀地分散在甲醇中。蒸发甲醇后，得到Nafion/MWNTs复合膜修饰电极。在0.01 mol L-1H 2SO 4介质中（pH 2.0），咖啡因在Nafion/MWNTs复合膜修饰电极上可有效富集，并在1330 mV（vs. SCE）附近产生一灵敏的阳极氧化峰。与裸电极和Nafion膜修饰电极相比，Nafion/MWNTs膜修饰电极能显著提高咖啡因的阳极峰电流。在适宜的条件下，咖啡因浓度在6.0 × 10（-7）~ 4.0 × 10（-4）mol L-1范围内与峰电流呈良好的线性关系，检测限为2.3 × 10（-7）mol L-1。Nafion/MWNTs复合膜修饰电极可在空白溶液中重复循环约3次而得到更新。该方法已成功地应用于饮料中咖啡因的测定。(C)2009 Elsevier B. V.保留所有权利。
A Nafion/multi-wall carbon nanotubes (MWNTs) composite film-modified electrode was fabricated and applied for the sensitive and selective determination of caffeine. Multi-wall carbon nanotubes (MWNTs) were easily dispersed homogeneously into methanol by ultrasonication in the presence of 0.1% Nafion. After evaporating the methanol, a Nafion/MWNTs composite film-modified electrode was achieved. Caffeine can be effectively accumulated at Nafion/MWNTs composite film-modified electrode and produce a sensitive anodic peak at around 1330 mV (vs. SCE) in a 0.01 mol L-1 H2SO4 medium (pH 2.0). Compared to the bare electrode and Nafion film-modified electrode, the Nafion/MWNTs film-modified electrode can remarkably increase the anodic peak current of caffeine. Under the suitable conditions, the anodic peak current was linear to caffeine concentration in the range of 6.0 x 10(-7) -4.0 x 10(-4) mol L-1, and the limit of detection was 2.3 x 10(-7) mol L-1. The Nafion/MWNTs composite film-modified electrode can be renewed by repetitiously cycling in a blank solution for about three cycles. This newly exploited method was successfully used to determine caffeine in beverage samples. (C) 2009 Elsevier B.V. All rights reserved.