Hierarchical nanocomposites of Co3O4/polyaniline nanowire arrays/reduced graphene oxide sheets for amino acid detection

The hierarchical nanocomposites of Co 3 O 4 /polyaniline (PANI) nanowire arrays/reduced graphene oxide sheets (rGO) was synthesized and characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetric analysis. The electrocatalytic oxidation and detection of cysteine or N -acetyl cysteine based on the nanocomposites modified glassy carbon electrodes were investigated by cyclic voltammetry, double potential step chronoamperometry and amperometric responses. The results suggested that the modified electrode showed good electrocatalytic performance for cysteine and N-acetyl cysteine. Two linear calibration ranges of 12–1280   μM and 1280–20,800   μM were obtained and the detection limit was estimated to be 4.0   μM according to the first linear calibration range. For the N -acetyl cysteine, two linear ranges were from 12 to 2560   μM and 2560 to 24,800   μM, respectively. The detection limit was estimated to be 5.2   μM according to the first linear calibration range.