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.
