Preparation of crumpled reduced graphene oxide–poly(p-phenylenediamine) hybrids for the detection of dopamine

In this work, reduced graphene oxide–poly(p-phenylenediamine) (rGO–PpPD) hybrids have been successfully prepared through a facile and effective method by heat treatment of GO aqueous dispersion in the presence of pPD at 80 °C for 2 h. The combined characterization by scanning electron microscopy (SEM), transmission electron microscopy (TEM), infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) indicates the successful production of rGO–PpPD hybrids with a crumpled morphology. The formation of rGO–PpPD hybrids is attributed to the redox reactions between GO and pPD, where the reduction of GO to rGO and polymerization of pPD into PpPD occurred simultaneously. It was found that rGO–PpPD hybrids show good catalytic activity toward oxidation of dopamine (DA), and no response to ascorbic acid (AA) and uric acid (UA), leading to a high-performance DA sensor. The linear detection ranges are estimated to be from 5 μM to 25 μM (r = 0.998) and 50 μM to 200 μM (r = 0.995), respectively. The detection limit is estimated to be 0.36 μM at a signal-to-noise ratio of 3.