Electrochemical sensor for facile detection of trace N-nitrosodiphenylamine based on poly(diallyldimethylammonium chloride)-stabilized graphene/platinum nanoparticles
N-Nitrosodiphenylamine (NDPhA), a typically nonvolatile N-nitrosamine (NA), is widely used as an additive in daily human necessities and is considered as a possible cancer-causing substance by the US Environmental Protection Agency. Therefore, the determination of NDPhA in environment is crucial to people's health. In this study, a simple and high-performance electrochemical sensor for NDPhA detection is constructed based on poly(diallyldimethylammonium chloride)-stabilized graphene/platinum nanoparticles (PDDA–Gr/PtNPs) as an electrochemical sensing platform. The PDDA–Gr/PtNP nanocomposite is synthesized by a facile wet-chemical approach. It combines the prominent properties of graphene (large surface areas and high conductivity) with the outstanding catalytic activity of Pt nanoparticles. Because of its remarkable synergistic effect, a PDDA–Gr/PtNP-modified glassy carbon electrode (PDDA–Gr/PtNPs/GCE) shows excellent performance towards electrooxidation of NDPhA with a significantly increased peak current and negatively shifted peak potential compared to graphene-modified electrode (PDDA–Gr/GCE); it exhibits good linearity for NDPhA detection with a linear range of 1.0 × 10−7–5.0 × 10−5 mol L−1 and a detection limit of 3.3 × 10−8 mol L−1 (S/N = 3) under optimum conditions. Moreover, this cost-effective and convenient sensor also has good stability, repeatability and anti-interference ability and is promising for trace analysis of NAs in environmental pollutants.