▎ 摘　　要

In this paper, an electrochemical sensor that can quickly and precisely determine the amount of caffeine (CAF) in various beverage using graphene based zirconia (ZrO2) nanocomposite modified glassy carbon electrode (GCE) was produced. The particle size of the nanomaterials was determined as 5-7 nm by TEM and XRD techniques. The modified GCEs were prepared by dropping the nanomaterial dispersions onto GCE and electrochemical behavior of the electrodes was investigated using voltammetric techniques (CV and DPV). DPV result showed that xGnP-ZrO2 nanocomposite modified GCE has a low detection limit (i.e., 1.19 x 10(-8) M) in 0.1 M H2SO4 medium at the range of 1 x 10(-6)-2x10(-3) M of CAF concentration. A relative standard deviation (RSD) of an acceptable value below 5% was observed. It also exhibited good selectivity for components that might show common interference in the same medium as the CAF. The results revealed that proposed method has the potential for CAF detection.