A Nanocomposite Containing Carbon Nano‐onions and Polyaniline Nanotubes as a Novel Electrode Material for Electrochemical Sensing of Daidzein

Abstract Glassy carbon electrode (GCE) were modified with nanocomposites containing conductive polyaniline nanotubes (PANInt) and carbon nano‐onions (CNOs). Herein we report a simple and sensitive way for daidzein (DA) determination at concentrations between 1 and 10 μM by linear sweep voltammetry using GCE/PANInt/CNOs system. The DA electrochemical behavior was examined in two buffer environments (pH 7.5 and 4.5) using electrodes modified with the oxidized CNOs or their derivatives containing carboxyl and benzylamino functional groups. The direct electrooxidation of DA was observed at +0.65 V and +0.8 V at pH 7.5 and at +0.7 V and +1.1 V vs. Ag/AgCl at pH 4.5.