▎ 摘　　要

NOVELTY - Electrochemical sensor comprises three independent channels consisting of a carbon-printed electrode with a working electrode with a circular center provided with an annular reference electrode and reference electrode. By printing the electrodes on the printed circuit board substrate and coating the working electrode surface with a semiconductor composite film containing carbon nanotubes or graphene with a thickness of 15 nm to 3 mu m and a metal catalyst layer by a technique of cyclic voltage scanning or constant voltage electrolysis to modify the electrode surface. USE - The sensor is useful for detecting methanol in a liquid medium. ADVANTAGE - The sensor: detects methanol sensitive to the change in voltage of the working electrode relative to the counter electrode; and is integrated with a portable electrochemical meter developed by the research team allowing field sample analysis in a short time and with high accuracy compared to traditional analytical methods.