An electrochemical-sensing platform for determination of dopamine (DA) was fabricated using MnO2-polyaniline (MnO2-PANI) composite. The MnO2-PANI composite was prepared through in situ radio-frequency plasma polymerization of aniline monomer over MnO2 under rotating conditions and followed by external iodine doping to boost conductivity of final I-2-MnO2-PANI sample. The structural and morphological analyses of the composite were carried out using Fourier-transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. Differential pulse voltammetry was used as an effective electrochemical method for detection of dopamine. I-2-MnO2-PANI composite-based sensor shows enhanced electrocatalytic activity and high selectivity towards DA in the presence of its major interferences, which are ascorbic acid and uric acid. The sensor showed a linear detection range from 12.4 to 185.2 mu M with a detection limit of 2.4 mu M. The sensor also exhibited long-term stability and reproducibility. Plasma process offers facile and fast production of electrode materials.