Author(s)

Ke Chen¹, Haoyu Shen^1*, Zhejun Wang¹, Amen Zhou¹, Qinghua Xia²

¹Biological and Chemical Engineering School, Ningbo Institute of Technology, Zhejiang University, Ningbo, China.
²Hubei Collaborative Innovation Center for Advanced Organochemical Materials, & Ministry-of-Education Key Laboratory for the Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan, China.

Carboxylic acid-functionalized nano-sized magnetic composite polymers (COOH-NMPs) were synthesized and used for the preparation of the modified glassy carbon electrode, i.e., COOH-NMPs/GCE and DNA/COOH-NMPs/GCE. The electrochemical behaviors of melamine (MM) were investigated on COOH-NMPs/GCE by cyclic voltammetry (CV) in both cases of DNA in the solution and immobilized on the electrode surface. The electron transfer coefficient (a) and the rate constant (k_s) kept unchanged in the absence and presence of DNA. Based on the electrochemical properties of the interaction of MM on the surface of the DNA/COOH-NMPs/GCE, a direct method for the determination of MM in liquid milk was established. The detection limit of this method was 2.0 ng·L^﹣1, with average recoveries at 95.9% - 104.2% and RSD at 4.5% - 8.2%. The proposed method was provided to have a good accuracy, high stability and good reproducibility with a simple and environmental friendly process. 10 kinds of liquid milk samples bought from the market randomly were tested, and only 1 of them was found at relatively low level of MM residue with the amount of 0.12 ug·L^﹣1.

Carboxylic Acid-Functionalized, Nano-Sized Magnetic Composite Polymers (NMPs), Melamine (MM), Herring Sperm DNA (HS-DNA), Interaction, Analytical Application, Determination of Melamine

Chen, K. , Shen, H. , Wang, Z. , Zhou, A. and Xia, Q. (2015) Voltammetric Study of the Interaction between Melamine and DNA on a Carboxylic Acid-Functionalized Nano-Fe₃O₄ Modified Electrode and Its Analytical Application for Melamine Determination in Liquid Milk Samples. American Journal of Analytical Chemistry, 6, 263-273. doi: 10.4236/ajac.2015.64025.