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 ofN-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 (2s) 8.0×10-7, M.
