Fabrication of Nanocomposite Containing Naphthoquinone and Nanogold Supported on Poly(2,6-pyridinedicarboxylic acid) Film for Voltammetric Determination of N-Acetyl-L-Cysteine

A modified electrode was fabricated by grafting of poly (2,6‐pyridinedicarboxylic acid) film (PDC) by electropolymerization of 2,6‐pyridinedicarboxylic acid on the glassy carbon electrode (GCE). Then, gold nanoparticles (NG) and 1,2‐naphthoquinone‐4‐sulfonic acid sodium (Nq) were immobilized on the PDC/GCE to prepare Nq/NG/PDC/GCE by immersing electrode into NG and Nq solution, respectively. The Nq species on NG/PDC/GCE could catalyze electrooxidation of N‐acetyl‐L‐cysteine (NAC) with lowering the over potential by about 600 mV. This method used for detection of NAC in dynamic range from 4.0×10−6 M to 1.30×10−4 M with a detection of limit (2σ) 8.0×10−7 M.