A highly selective electrochemical sensor for nifedipine based on layer-by-layer assembly films from polyaniline and multiwalled carbon nanotube.

ABSTRACT An uniformly distributed film consisting of polyaniline (PANI) nanoparticles and carboxylic acid functionalized multiwalled carbon nanotubes (MWNTs-COOH) was successfully assembled on ITO plates from a layer-by-layer (LBL) method by using electrostatic interactions as the main driving force. The good conjugation between PANI nanoparticles and MWNTs-COOH resulted in significant electrochemical performance variation of the obtained films. In addition, the assembled MWNT-COOH/PANI/ITO showed synergistic effect to the electrochemical oxidation of nifedipine (NIF) when used as a sensor. Compared with bare ITO, the oxidation potential of NIF can be decreased about 170 mV on MWNT-COOH/PANI/ITO, and the lower detection limit of NIF was as low as 1.0 × 10⁻⁶ mol/L. In addition, the assembled electrode gave no responses to interferences such as glucose, urea, ascorbic acid, and trisodium citrate, which showed high selectivity for recognition and quantification of NIF. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43452. [ABSTRACT FROM AUTHOR]