Plasma-assisted synthesis of MnO2–polyaniline composite for electrochemical sensing of dopamine

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 I2–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. I2–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 μM with a detection limit of 2.4 μM. The sensor also exhibited long-term stability and reproducibility. Plasma process offers facile and fast production of electrode materials.