Synthesis and Application of Polyaniline/Multi Walled Carbon Nanotube Nanocomposite for Electrochemical Determination of Folic acid

A composite of polyaniline with multi-wall-carbon nanotubes (PANi/MWCNTs) was synthesized by an in situ chemical oxidative polymerization method. The PANi were synthesized chemically using aniline as the monomer and ammonium peroxydisulfate as the oxidant. The PANi/MWCNTs were characterized physically using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). With this nano composite as the modifier, a voltammetric sensor for folic acid (FA) was constructed on a glassy carbon electrode (GCE). Folic acid undergoes a 2e-/2H+ transfer electrochemical reduction process at 0.7 V with respect to Ag/AgCl reference electrode in pH 7. PANi/MWCNTs modified electrode showed good cyclic voltammetric (CV) response in wide linear range from 10-6 M to 10-4 M. This modified showed excellent sensitivity and stability for determination of folic acid. The response mechanism of folic acid at PANi-MWCNTs/GCE was discussed in detail.