TITLE:
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
AUTHORS:
Ke Chen, Haoyu Shen, Zhejun Wang, Amen Zhou, Qinghua Xia
KEYWORDS:
Carboxylic Acid-Functionalized, Nano-Sized Magnetic Composite Polymers (NMPs), Melamine (MM), Herring Sperm DNA (HS-DNA), Interaction, Analytical Application, Determination of Melamine
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.6 No.4,
March
3,
2015
ABSTRACT: 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 (ks) 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.