In this work, a gold electrode modified with selfassembled layers (SAMs) composed of 3-mercaptopropionic acid, cysteamine and gold nanoparticles was prepared. The electrode with SAMs endowed with gold nanoparticles gave the high catalytic effect for monoethanolamine (MEA) electrooxidation in solution at pH 7. For this novel sensor, a linear relationship between the current response of MEA at the potential of peak maximum (j p ) and the concentration of this compound in solution (c MEA ) was found, over the range 0.1 μM to 0.8 M with the detection sensitivity equal to about 5 A cm −2 mol −1 dm 3 (at v=0.1 V s −1 ) and the detection limit of 0.046 μM.