In this study, the simple, green, and fast layer‐by‐layer modification of the glassy carbon electrode was mainly performed by electrodeposition of gold nanoparticles and then, poly‐l‐arginine, and finally, laccase was covalently bonded to poly‐l‐arginine using glutaraldehyde. This type of fabrication is used for the first time for catechol detection, which provides a bioelectrocatalytic cycle for electron transport in the presence of laccase that results in sensitive and fast detection of catechol. The scanning electron microscopy, Fourier‐transform infrared spectroscopy, and electrochemical studies were performed to confirm successful immobilization of the enzyme. The biosensor response was linear in a wide range of catechol trace concentrations, 24.90–274.00 nM, with the detection limit of 18.00 nM. Values of Km, α, n, and Ks for the immobilized enzyme were calculated to be 1.25 × 10−2 µM, 0.56, 3.19, and 0.28 Sec−1, respectively. It was examined in real sample successfully confirming it is capable of measuring catechol in natural water.