Herein, an electrochemical method is presented for the detection of curcumin in food using a carbon nanotube (CNT)-carboxymethylcellulose (CMC) electrode. The CNT-CMC electrode exhibited ideal characteristics for curcumin detection, namely, a high response current and adequate peak separation toward curcumin oxidation. Cyclic voltammetry revealed two oxidation peaks. In the first scan, only the irreversible peak (Peak I) was observed at a higher potential. In the second scan, the reversible redox peak pairs (Peaks II and II′) appeared at lower potentials, and the potential of Peak I was decreased. Peak I corresponded to oxidation of the hydroxyl groups of the benzene ring to the catechol group via a phenoxy radical, while Peaks II and II′ indicated the redox loop system of the generated catechol group. The current at Peak II was used to quantify the concentration of curcumin in the linear range of 1 – 48 μM and detection limit of 0.084 μM. The concentrations of curcumin determined by the CNT-CMC electrode in real food samples were consistent with those determined by high-performance liquid chromatography.

本文提出了一种使用碳纳米管（CNT）-羧甲基纤维素（CMC）电极检测食品中姜黄素的电化学方法。CNT-CMC电极表现出姜黄素检测的理想特性，即高响应电流和对姜黄素氧化的足够的峰分离。循环伏安法显示出两个氧化峰。在第一次扫描中，仅在较高电位处观察到不可逆峰（峰 I）。在第二次扫描中，可逆氧化还原峰对（峰II和II'）出现在较低电位，并且峰I的电位降低。峰 I 对应于苯环上的羟基通过苯氧基氧化为儿茶酚基团，而峰 II 和 II' 表示生成的儿茶酚基团的氧化还原环系统。峰 II 处的电流用于量化姜黄素浓度，线性范围为 1 – 48 μM，检测限为 0.084 μM。CNT-CMC电极测定的实际食品样品中姜黄素的浓度与高效液相色谱法测定的浓度一致。