Enhanced electrochemical detection of erythromycin based on acetylene black nanoparticles.

Acetylene black nanoparticles (AB) were dispersed into water in the presence of dihexadecyl hydrogen phosphate (DHP), and used to modify the surface of glassy carbon electrode (GCE) via solvent evaporation. Due to the high sorption ability, large surface area and numerous active sites, the AB-modified GCE showed a strong enhancement effect on the oxidation of erythromycin, and greatly increased the peak current. The oxidation mechanism was investigated at the surface of AB-modified GCE, and two oxidation peaks were observed for erythromycin. The first oxidation peak is attributed to the removal of one electron from the nitrogen atom to form an aminium cation radical, and the second peak is due to the oxidation of the chemical product of aminium cation radical. The influence of pH value, amount of AB, accumulation potential and time was also studied, and a novel electrochemical method was developed for the determination of erythromycin. The linear range is from 2 x 10(-7) to 1 x 10(-5)M, and the limit of detection is 8 x 10(-8)M (58.72 microg L(-1)). Copyright (c) 2010 Elsevier B.V. All rights reserved.