Gallic acid (GA) is a natural phenolic compound with significant biological properties, including anti‐inflammatory, antioxidant, and anticancer effects. Detecting GA in biological matrices like food and beverages is essential but challenging due to the multitude of GA‐like molecules with similar proprieties and functional moieties. In this study, ultra‐small (≈4 nm) pyramidal platinum nanoparticles (PtNPs) with a high fraction of {111} surface domains are used to design a new electrochemical sensor for GA detection in tea, which is the most popular manufactured drink consumed in the world. PtNPs are deposited on a glassy carbon electrode (GCE) using a simple drop deposition method, requiring a minimal amount of nanoparticles and, hence, metal precursor. With just 2.7 µg of PtNPs, the sensor demonstrated a linear response in the concentration range from 50 to 600 µm, a detection limit of 16 µm, and a quantification limit of 49 µm. The sensor selectivity is tested against other antioxidant compounds commonly present in tea, consistently showing a higher response for GA. Furthermore, the sensor capability to detect GA in real green and black tea samples is further validated by high‐performance liquid chromatography (HPLC) analysis, with high correlation between chromatographic data and sensor response.

中文翻译：

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使用锥体 Pt 纳米颗粒电化学测定茶叶样品中的没食子酸


没食子酸 （GA） 是一种天然酚类化合物，具有显着的生物学特性，包括抗炎、抗氧化和抗癌作用。检测食品和饮料等生物基质中的 GA 是必不可少的，但由于具有相似特性和功能部分的大量 GA 样分子，因此具有挑战性。在这项研究中，具有高 {111} 表面畴的超小 （≈4 nm） 金字塔形铂纳米颗粒 （PtNPs） 被用来设计一种新的电化学传感器，用于检测茶中的 GA，茶是世界上最受欢迎的制造饮料。PtNPs 使用简单的液滴沉积方法沉积在玻碳电极 （GCE） 上，需要最少的纳米颗粒，因此需要金属前驱体。仅使用 2.7 μg PtNP，该传感器在 50 至 600 μm 的浓度范围内表现出线性响应，检测限为 16 μm，定量限为 49 μm。传感器选择性针对茶中常见的其他抗氧化化合物进行了测试，始终显示对 GA 的响应更高。此外，高效液相色谱 （HPLC） 分析进一步验证了传感器检测真实绿茶和红茶样品中 GA 的能力，色谱数据与传感器响应之间具有高度相关性。