A novel electrochemical sensor was fabricated by electrodeposition of gold nanoparticles on a poly(L-methionine) (PMT)-modified glassy carbon electrode (GCE) to form a nano-Au/PMT compo-site-modified GCE (nano-Au/PMT/GCE). Scanning electron microscopy and electrochemical tech-niques were used to characterize the composite electrode. The modified electrode exhibited con-siderable electrocatalytic activity towards the oxidation of dopamine (DA) and uric acid (UA) in phosphate buffer solution (pH = 7.00). Differential pulse voltammetry revealed that the electrocat-alytic oxidation currents of DA and UA were linearly related to concentration over the range of 5.0 × 10-8 to 10-6 mol/L for DA and 7.0 × 10-8 to 10-6 mol/L for UA. The detection limits were 3.7 × 10-8 mol/L for DA and 4.5 × 10-8 mol/L for UA at a signal-to-noise ratio of 3. According to our experi-mental results, nano-Au/PMT/GCE can be used as a sensitive and selective sensor for simultaneous determination of DA and UA.