Aniline-nonamer segmented polyurea: A facile electrocatalyst for detection of ascorbic acid

An unprecedented A-B-A type block copolymer electroactive polyurea (EPU) is designed and synthesized with tetraaniline dimer and 1,4-phenylenediamine via an oxidative coupling, where aniline-nonamer and hexamethylene di-urea constitute two segments. The EPU was characterized by spectral techniques such as Fourier transform infrared spectroscopy, nuclear magnetic resonance, and UV-vis spectra. The structural characterization of the prepared EPU was obtained by powder X-ray diffraction and X-ray photoelectron spectroscopy techniques. EPU reorganizes into core-shell microcapsules in presence of aqueous acetic acid/n-octane interface. These microcapsules exhibited a wide range of pH responses in their absorption spectrum (UV-vis). The EPU is modified as carbon paste electrode which exhibits a remarkable electrocatalytic oxidation of ascorbic acid (AA, Vitamin C) in 0.2 M and pH 7.0 phosphate buffer solution. The carbon paste electrode is useful in sensing as low as 50 mu M of ascorbic acid. This can open up new opportunities for fast, simple detection of AA providing a promising platform for sensor/biosensor designs for AA detection. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46630.