School of Food & Pharmaceutical Engineering, Zhaoqing University, Zhaoqing 526061, China.
Guangdong Engineering Technology Research Center for Food & Agricultural Product Safety Analysis and Testing, Zhaoqing 526061, China.
Molecules. 2019 Aug 22;24(17):3041. doi: 10.3390/molecules24173041.
A hybrid nanocomposite consisting of hydroxylated multi-walled carbon nanotubes (MWCNTs-OH) and cube mesoporous carbon (CMK-8) was applied in this study to construct an MWCNT-OH/CMK-8/gold electrode (GE) electrochemical sensor and simultaneously perform the electro-reduction of olaquindox (OLA) and carbadox (CBX). The respective peak currents of CBX and OLA on the modified electrode increased by 720- and 595-fold relative to the peak current of GE. The performances of the modified electrode were investigated with electrochemical impedance spectroscopy, cyclic voltammetry, and differential pulse voltammetry. Then, the modified electrodes were used for the individual and simultaneous determination of OLA and CBX. The fabricated sensor demonstrated a linear response at 0.2-500 nmol/L in optimum experimental conditions, and the detection limits were 104.1 and 62.9 pmol/L for the simultaneous determination of OLA and CBX, respectively. As for individual determination, wide linear relationships were obtained for the detected OLA with levels of 0.05-500 nmol/L with LOD of 20.7 pmol/L and the detected CBX with levels of 0.10-500 nmol/L with LOD of 50.2 pmol/L. The fabricated sensor was successfully used in the independent and simultaneous determination of OLA and CBX in spiked pork samples.
本研究应用了一种由羟基化多壁碳纳米管 (MWCNTs-OH) 和立方介孔碳 (CMK-8) 组成的混合纳米复合材料，构建了 MWCNT-OH/CMK-8/金电极 (GE) 电化学传感器，并同时实现了奥拉喹多 (OLA) 和卡巴多 (CBX) 的电还原。与 GE 的峰电流相比，修饰电极上 CBX 和 OLA 的相应峰电流分别增加了 720 倍和 595 倍。通过电化学阻抗谱、循环伏安法和差分脉冲伏安法研究了修饰电极的性能。然后，使用修饰电极对 OLA 和 CBX 进行了单独和同时的测定。在最佳实验条件下，所制备的传感器在 0.2-500 nmol/L 范围内呈现线性响应，同时测定 OLA 和 CBX 的检测限分别为 104.1 和 62.9 pmol/L。对于单独测定，检测 OLA 的水平在 0.05-500 nmol/L 范围内具有较宽的线性关系，检测限为 20.7 pmol/L，检测 CBX 的水平在 0.10-500 nmol/L 范围内具有较宽的线性关系，检测限为 50.2 pmol/L。所制备的传感器成功地用于检测加标猪肉样品中 OLA 和 CBX 的独立和同时测定。
