Electrochemical sensor with electrohydrodynamic-printed microelectrodes for the detection of low concentration of tea polyphenols

The accurate quantification of tea polyphenols plays a crucial role in the quality inspection of tea and various food products. With the advantages of high sensitivity and selectivity, electrochemical method has gained widespread utilization in detecting tea polyphenols. The accuracy of electrochemical detection heavily relies on the dimensions of the microelectrodes utilized. In the present work, six microelectrode systems with varying diameters (70, 200, 300, 500, 800, and 1000 μm) were manufactured by electrohydrodynamic printing method and integrated into sensors to detect low concentration of tea polyphenols. The performances of sensors were evaluated in terms of detection limits, sensitivity, and linear range. The results demonstrated that sensors with minor microelectrodes exhibited superior detection limits and sensitivity. The sensor featuring a 70 μm microelectrode demonstrated a linear range of 1-70 μmol/L and a low detection limit of 0.22 μmol/L. Average recovery rates of sensors ranging from 95.2% to 105.0% were obtained in detecting tea polyphenols in green tea, confirming the remarkable potential for rapid and accurate detection of low concentration of tea polyphenols in real samples.