Determination of Oxytetracycline with a Gold Electrode Modified by Chitosan-Multiwalled Carbon Nanotube Multilayer Films and Gold Nanoparticles

Abstract

A molecularly imprinted electrochemical sensor was fabricated based on a gold electrode modified by chitosan-multiwalled carbon nanotube composite (CS-MWCNTs) multilayer films and gold nanoparticles (AuNPs) for convenient and sensitive determination of oxytetracycline (OTC). The multilayer of CS-MWCNTs composites and AuNPs were used to augment electronic transmission and sensitivity. The molecularly imprinted polymers (MIPs) were synthesized using OTC as the template molecule and o-phenylenediamine (OPD) as the functional monomer. They were modified on a gold electrode by electropolymerization. The electrochemical behavior of OTC at the imprinted sensor was characterized by cyclic voltammetry (CV), scanning electron microscopy (SEM), and amperometry. The molecularly imprinted sensor showed high selectivity and excellent stability toward OTC. The linear range was from 3.0 × 10⁻⁸ to 8.0 × 10⁻⁵ mol/L, with a limit of detection (LOD) of 2.7 × 10⁻⁸ mol/L (S/N = 3). The developed sensor showed good recovery in spiked samples analysis.

Keywords:

• Chitosan-multiwalled carbon nanotube composites
• Electrochemical sensor
• Gold nanoparticles
• Molecularly imprinted polymers
• Oxytetracycline detection

Acknowledgments

This work was supported by the National Natural Science Foundation of the People's Republic of China (No. 30972056, 31171700 and 31101296), the National High Technology Research and Development Program of China (National 863 Program of China) (No. 2012AA101604), the Foundation for Outstanding Young Scientist in Shandong Province (No. BS2009NY001), the Scientific and Technological Development Plan in Shandong Province (No. 2010GNC10960), the Natural Science Foundation of Shandong Province (No. ZR2010DQ025), and the Shandong Province Higher Educational Science and Technology Program (No. J10LB14).