In several industries, such as food, pharmaceuticals, and environmental protection, the identification of analytes at extremely low concentrations is essential. In the food standardization field, electrochemical sensors are one of the key technologies for determining food quality and making medical diagnoses. Sensor design is dependent on electrochemically active characteristics of the selected material to alter the electrode. For rapid and accurate detection of caffeine (CAF), we technologically built an electrochemical sensor based on functionalized multi-walled carbon nanotubes (f-MWCNTs/GCE). The functionalized material was characterized by XRD, Raman, FT-IR, FE-SEM, HR-TEM, EDX and the mapping of elements. The component’s natural virtue and cooperative connection demonstrate enhanced electrocatalytic activity, as evidenced by the component’s decreased overpotential, increased electron transfer, improved sensing and selectivity, broad linear range, and low detection limit toward the selected analyte. CAF was found to have broad linear ranges of concentrations 5.3 to 166 µM, with detection limits of 0.043 µM. 9.13 µA. µm− 1 is the designed electrode's sensitivity. High selectivity, stability, repeatability and reproducibility were also demonstrated by the electrode. Crucially, the investigation was effective in identifying and measuring the aforementioned element in authentic specimens. In addition, the sensor demonstrated efficacy in detecting CAF in drinks, yielding good recoveries ranging from 96.4–102.4%. This suggests that the sensor holds desirable potential for identifying CAF real substances.