Xu Jing-Wen, Cui Zhuo-Miao, Liu Zhan-Qing, Xu Feng, Chen Ya-Shao, Luo Yan-Ling
Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China.
School of Food & Biological Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
Nanomaterials (Basel). 2019 Sep 27;9(10):1388. doi: 10.3390/nano9101388.
An electrochemical sensor for detection of the content of aspartame was developed by modifying a glassy carbon electrode (GCE) with multi-walled carbon nanotubes decorated with zinc oxide nanoparticles and in-situ wrapped with poly(2-methacryloyloxyethyl ferrocenecarboxylate) (MWCNTs@ZnO/PMAEFc). MWCNTs@ZnO/PMAEFc nanohybrids were prepared through reaction of zinc acetate dihydrate with LiOH·HO, followed by reversible addition-fragmentation chain transfer polymerization of 2-methacryloyloxyethyl ferrocenecarboxylate, and were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), Raman, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM), scanning electron microscope (SEM), and transmission electron microscope (TEM) techniques. The electrochemical properties of the prepared nanohybrids with various composition ratios were examined by cyclic voltammetry (CV), and the trace additives in food and/or beverage was detected by using differential pulse voltammetry (DPV). The experimental results indicated that the prepared nanohybrids for fabrication of electrochemical modified electrodes possess active electroresponse, marked redox current, and good electrochemical reversibility, which could be mediated by changing the system formulations. The nanohybrid modified electrode sensors had a good peak current linear dependence on the analyte concentration with a wide detection range and a limit of detection as low as about 1.35 × 10 mol L, and the amount of aspartame was measured to be 35.36 and 40.20 µM in Coke zero, and Sprite zero, respectively. Therefore, the developed nanohybrids can potentially be used to fabricate novel electrochemical sensors for applications in the detection of beverage and food safety.
通过用装饰有氧化锌纳米颗粒并原位包裹聚（2-甲基丙烯酰氧基乙基二茂铁甲酸酯）（MWCNTs@ZnO/PMAEFc）的多壁碳纳米管修饰玻碳电极（GCE），开发了一种用于检测阿斯巴甜含量的电化学传感器。MWCNTs@ZnO/PMAEFc纳米杂化物通过二水合醋酸锌与LiOH·H₂O反应制备，随后进行2-甲基丙烯酰氧基乙基二茂铁甲酸酯的可逆加成-断裂链转移聚合，并通过傅里叶变换红外光谱（FTIR）、热重分析（TGA）、拉曼光谱、X射线衍射（XRD）、X射线光电子能谱（XPS）、原子力显微镜（AFM）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）技术进行表征。通过循环伏安法（CV）研究了制备的具有不同组成比的纳米杂化物的电化学性质，并使用差分脉冲伏安法（DPV）检测食品和/或饮料中的痕量添加剂。实验结果表明，制备的用于制造电化学修饰电极的纳米杂化物具有活性电响应、明显的氧化还原电流和良好的电化学可逆性，可通过改变体系配方来调节。纳米杂化物修饰电极传感器的峰电流与分析物浓度具有良好的线性相关性，检测范围宽，检测限低至约1.35×10⁻⁸ mol/L，在零度可乐和零度雪碧中测得的阿斯巴甜含量分别为35.36和40.20 μM。因此，所开发的纳米杂化物有可能用于制造新型电化学传感器，应用于饮料和食品安全检测。
