Tang Hao, Shen Jian, Dai Jindong, Rajalakshmi Kanagaraj, Muthusamy Selvaraj, Kannan Palanisamy, Zhu Dongwei, You Benshuai, Liu Xiaojian
Department of Clinical Laboratory, Affiliated People's Hospital of Jiangsu University, 212006 Zhenjiang, Jiangsu, PR China.
Department of Immunology, Jiangsu Key Laboratory of Laboratory Medicine, School of Medicine, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
Food Chem. 2025 Nov 15;492(Pt 1):145337. doi: 10.1016/j.foodchem.2025.145337. Epub 2025 Jun 25.
3-Caffeoylquinic acid (3-CQA), a prominent phenolic acid, plays a critical role in glucose metabolism and is associated with the prevention of type-2 diabetes. The selective and sensitive detection of 3-CQA remains challenging due to interferences from substances such as caffeine (CAF) and the instability of signals from unmodified electrodes. To address this, this study developed a nanostructured conducting polymer composite based on acid-functionalized multi-walled carbon nanotubes (FMWCNTs) and 3-amino-5-mercapto-1,2,4-triazole (AMTa), which was integrated onto a glassy carbon electrode (GCE) for the selective detection of 3-CQA. The composite electrode (GCE/OD/FMWCNTs/p-AMTa) was thoroughly characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and electrochemical analysis. In contrast to the unmodified GCE, which fails to maintain a stable voltametric profile for 3-CQA detection due to the deposition of its oxidation products, the composite-modified electrode demonstrates a stable electrochemical response, with a fourfold increase in the catalytic oxidation current. This improvement is attributed to the strong electrostatic and hydrogen-bonding interactions between the heteroatoms in the polymer backbone of p-AMTa and 3-CQA, as well as the π-π interactions between FMWCNTs and the aromatic ring of 3-CQA. Additionally, selective determination of 3-CQA is achieved even in the presence of 500 times the concentration of CAF. The amperometric i-t curve exhibits a significant increase in response to 3-CQA concentrations ranging from 0.1 to 200 μM, with a detection limit (LOD) of 30 nM (S/N = 3). The proposed sensor demonstrates excellent performance in detecting 3-CQA in blood, coffee, tea, and various food samples, yielding satisfactory recovery results.
3-咖啡酰奎宁酸（3-CQA）是一种重要的酚酸，在葡萄糖代谢中起关键作用，并与2型糖尿病的预防有关。由于咖啡因（CAF）等物质的干扰以及未修饰电极信号的不稳定性，对3-CQA进行选择性和灵敏检测仍然具有挑战性。为了解决这个问题，本研究开发了一种基于酸功能化多壁碳纳米管（FMWCNTs）和3-氨基-5-巯基-1,2,4-三唑（AMTa）的纳米结构导电聚合物复合材料，并将其集成到玻碳电极（GCE）上用于3-CQA的选择性检测。使用扫描电子显微镜（SEM）、傅里叶变换红外光谱（FT-IR）、原子力显微镜（AFM）、X射线光电子能谱（XPS）和电化学分析对复合电极（GCE/OD/FMWCNTs/p-AMTa）进行了全面表征。与未修饰的GCE相比，由于其氧化产物的沉积，未修饰的GCE在检测3-CQA时无法保持稳定的伏安曲线，而复合修饰电极表现出稳定的电化学响应，催化氧化电流增加了四倍。这种改进归因于p-AMTa聚合物主链中的杂原子与3-CQA之间的强静电和氢键相互作用，以及FMWCNTs与3-CQA芳环之间的π-π相互作用。此外，即使在CAF浓度为其500倍的情况下，也能实现对3-CQA的选择性测定。安培i-t曲线对0.1至200μM的3-CQA浓度响应显著增加，检测限（LOD）为30 nM（S/N = 3）。所提出的传感器在检测血液、咖啡、茶和各种食品样品中的3-CQA方面表现出优异的性能，回收率结果令人满意。
