基于微流控芯片的茶多酚电化学检测方法研究

Electrochemical Detection of Tea Polyphenols Based on Microfluidic Chip

摘要:

为解决茶多酚传统检测方法中存在操作复杂、自动化程度低、试剂消耗量大等问题，提出一种基于微流控芯片的茶多酚电化学检测方法。以3D打印微流控芯片为检测通道，丝网印刷碳电极为电化学传感器，建立了微流控检测平台，以没食子酸为检测标准品，采用循环伏安法，研究了缓冲液种类、缓冲液pH、扫描速度、进料流量4个因素对氧化峰电流的影响，并运用该方法对普洱茶样品中的茶多酚进行了测定。结果表明：在最优实验条件下，该方法在没食子酸浓度为5～1 250 μmol/L范围内具有线性响应，检出限为6.9×10^-7 mol/L，样品回收率在97.6%～104.6%，本检测结果与标准福林酚法的结果一致，检测时间为40 s，试剂用量70 μL。该方法具有试剂样品用量少、测试时间短等特点，可用于茶多酚含量的快速检测。

Abstract:

An electrochemical detection method based on microfluidic chip was proposed to improve complex operation, low degree of automation and large reagent-consuming in the tea polyphenols detection. The microfluidic detection platform was established with 3D printed microfluidic chip as the detection channel and screen-printed carbon electrode as the electrochemical sensor. The effects of various buffer solutions, pH values, scan rates and feed rates on the oxidation peak current in cyclic voltammetry detection were studied using gallic acid (GA) as the test standard. This method was then applied to determine the tea polyphenols in samples from Pu'er tea. This method achieved a linear response in the range of 5～1 250 μmol/L GA under the optimal experimental condition. In addition, the detection limit was 6.9×10^-7 mol/L and the recovery rate was between 97.6%and 104.6%.The result was consistent with the Folin-Ciocaulteau method. The detection time decreased to 40 s and the dosage of reagent was 70 μL. The proposed method has the advantage of less sample consumption and shorter detection time. It can be applied to the rapid detection of tea polyphenols.