Poly(aniline-co-diphenylamine and 5-aminosalicylic acid) used for the electrocatalytic reduction and determination of m-nitrophenol

• Poly(aniline-co-diphenylamine and 5-aminosalicylic acid) copolymer.
• Electrocatalytic reduction of m-nitrophenol by the copolymer film.
• m-Nitrophenol sensor constructed of the copolymer film and reduced graphene oxide.
• Good repeatability and long operational life of the sensor.

Poly(aniline-co-diphenylamine and 5-aminosalicylic acid), i.e., poly(aniline-co-DPA-and 5-ASA), was electrochemically synthesized in a acidic solution containing aniline, diphenylamine (DPA) and 5-aminosalicylic acid (5-ASA) in the presence of N,N-dimethylformamide (DMF), which was deposited on a reduced graphene oxide (RGO)/glassy carbon (GC) electrode to form a poly(aniline-co-DPA and 5-ASA)/RGO/GC electrode. Cyclic voltammetry demonstrated that this electrode can effectively catalyze the reduction of m-nitrophenol in aqueous solutions. Therefore, this electrode can be used to determine m-nitrophenol in aqueous media. The electrode exhibited a linear region of 20–400 μM m-nitrophenol in a phosphate buffer solution of pH 6.5 with a correlation coefficient of 0.9955, a linear region of 20–600 μM m-nitrophenol in a Na2SO4 solution of pH 6.0 with a correlation coefficient of 0.9997, a good repeatability and long working life.

Cyclic voltammograms of poly(aniline-co-DPA and 5-ASA)/RGO/GC electrode in 0.30 M Na2SO4 solution containing nitrophenols, curves: (1) containing 0.20 mM m-nitrophenol; (2) containing 0.20 mM m-nitrophenol and 0.20 mM o-nitrophenol; (3) containing 0.20 mM m-nitrophenol and 0.20 mM p-nitrophenol, pH 5.0, at a scan rate of 60 mV s−1.Figure optionsDownload as PowerPoint slide