AbstractA colorimetric array, which can discriminate 20 food antioxidants of natural, synthetic and biological groups, is described. It consists of gold and silver nanoparticles that were synthesized using six different reducing and/or capping agents. The function of the array relies on the interaction of the antioxidants with the nanoparticles which causes aggregation or morphological changes. This, in turn, causes a change in the sensors’ colors. The array produces a unique combination of colors for each antioxidant. The resulting colorations are determined by recording the absorbances of the arrays at wavelengths of 405, 450, 490 and 630 nm, or by capturing the images with a digital camera. The discriminatory ability of the array is investigated by principle component analysis and hierarchical cluster analysis. The method was applied to quantitative assay of gallic acid, caffeic acid, catechin, dopamine, citric acid, butylated hydroxytoluene and ascorbic acid. The respective limits of detection are 4.2, 13, 53, 6.9, 47, 3.5 and 43 nM, respectively. The simultaneous determination of 5 different antioxidants is achieved utilizing partial least square regression. The root mean square errors for prediction of the test set are 0.0650, 0.0782, 0.811, 0.0206 and 0.135 nM for gallic acid, catechin, butylated hydroxytoluene, dopamine, and ascorbic acid, respectively. This method demonstrates excellent potential for analysis of antioxidants in beverages such as tea and lemon juice. Graphical abstractSchematic of a method for the simultaneous determination of several antioxidants based on changes in the color of gold and silver nanoparticles. The antioxidants cause aggregation and/or morphological changes which can be detected by using both image analysis or by colorimetry.

中文翻译：

---

基于一系列金和银纳米粒子的光电舌，用于分析天然、合成和生物抗氧化剂

摘要描述了一种比色阵列，可以区分天然、合成和生物组的 20 种食物抗氧化剂。它由使用六种不同还原剂和/或封端剂合成的金和银纳米颗粒组成。阵列的功能依赖于抗氧化剂与纳米颗粒的相互作用，从而导致聚集或形态变化。这反过来又会导致传感器颜色发生变化。该阵列为每种抗氧化剂产生独特的颜色组合。通过记录阵列在 405、450、490 和 630 nm 波长处的吸光度，或通过用数码相机捕获图像来确定产生的颜色。通过主成分分析和层次聚类分析研究阵列的判别能力。该方法适用于没食子酸、咖啡酸、儿茶素、多巴胺、柠檬酸、丁基羟基甲苯和抗坏血酸的定量分析。各自的检测限分别为 4.2、13、53、6.9、47、3.5 和 43 nM。利用偏最小二乘回归实现了 5 种不同抗氧化剂的同时测定。对于没食子酸、儿茶素、丁基化羟基甲苯、多巴胺和抗坏血酸，测试集预测的均方根误差分别为 0.0650、0.0782、0.811、0.0206 和 0.135 nM。该方法在分析茶和柠檬汁等饮料中的抗氧化剂方面表现出出色的潜力。图形摘要基于金和银纳米粒子颜色变化同时测定几种抗氧化剂的方法示意图。