Biological Engineering Program, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand.
School of Materials Science and Innovation, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
Molecules. 2021 Apr 16;26(8):2312. doi: 10.3390/molecules26082312.
A facile synthesis of reduced graphene oxide (rGO) and methionine film modified screen printed carbon electrode (rGO-methionine/SPCE) was proposed as a disposable sensor for determination of food colorants including amaranth, tartrazine, sunset yellow, and carminic acid. The fabrication process can be achieved in only 2 steps including drop-casting of rGO and electropolymerization of poly(L-methionine) film on SPCE. Surface morphology of modified electrode was studied by scanning electron microscopy (SEM). This work showed a successfully developed novel disposable sensor for detection of all 4 dyes as food colorants. The electrochemical behavior of all 4 food colorants were investigated on modified electrodes. The rGO-methionine/SPCE significantly enhanced catalytic activity of all 4 dyes. The pH value and accumulation time were optimized to obtain optimal condition of each colorant. Differential pulse voltammetry (DPV) was used for determination, and two linear detection ranges were observed for each dye. Linear detection ranges were found from 1 to 10 and 10 to 100 µM for amaranth, 1 to 10 and 10 to 85 µM for tartrazine, 1 to 10 and 10 to 50 µM for sunset yellow, and 1 to 20 and 20 to 60 µM for carminic acid. The limit of detection (LOD) was calculated at 57, 41, 48, and 36 nM for amaranth, tartrazine, sunset yellow, and carminic acid, respectively. In addition, the modified sensor also demonstrated high tolerance to interference substances, good repeatability, and high performance for real sample analysis.
一种简便的还原氧化石墨烯（rGO）和蛋氨酸薄膜修饰的丝网印刷碳电极（rGO-蛋氨酸/SPCE）的合成方法被提出，作为一种用于测定包括苋菜红、柠檬黄、日落黄和胭脂红在内的食品着色剂的一次性传感器。该制备过程仅需 2 步，包括 rGO 的滴铸和聚 L-蛋氨酸薄膜在 SPCE 上的电聚合。通过扫描电子显微镜（SEM）研究了修饰电极的表面形貌。这项工作成功开发了一种新型的一次性传感器，用于检测所有 4 种作为食品着色剂的染料。在修饰电极上研究了所有 4 种食品着色剂的电化学行为。rGO-蛋氨酸/SPCE 显著增强了所有 4 种染料的催化活性。优化了 pH 值和积累时间，以获得每种染料的最佳条件。采用差分脉冲伏安法（DPV）进行测定，发现每种染料都有两个线性检测范围。苋菜红的线性检测范围为 1 至 10 和 10 至 100 µM，柠檬黄为 1 至 10 和 10 至 85 µM，日落黄为 1 至 10 和 10 至 50 µM，胭脂红为 1 至 20 和 20 至 60 µM。苋菜红、柠檬黄、日落黄和胭脂红的检测限（LOD）分别计算为 57、41、48 和 36 nM。此外，修饰后的传感器还表现出对干扰物质的高容忍度、良好的重复性和对实际样品分析的高性能。
