ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

An electrochemical sensor for sensitive determination of nitrites based on Ag–Fe3O4–graphene oxide magnetic nanocomposites

Bo-Qiang Li, Fei Nie, Qing-Lin Sheng, and Jian-Bin Zheng

Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, Institute of Analytical Science, Northwest University, Xi’an, Shaanxi 710069, China

E-mail: zhengjb@nwu.edu.cn

Abstract: A functional Ag-Fe₃O₄-grapheme oxide magnetic nanocomposite was synthesized and used to prepare a nitrite sensor. Morphology and composition of the nanocomposites were characterized by a transmission electron microscope, UV-VIS spectroscopy, X-ray diffraction, and Fourier transform infrared spectra. Electrochemical investigation indicated that the nanocomposites possess excellent electrochemical oxidation ability towards nitrites. The sensor exhibited two linear ranges: one from 0.5 μM to 0.72 mM with a correlation coefficient of 0.996 and sensitivity of 1996 μA mM⁻¹ cm⁻²; the other from 0.72 mM to 8.15 mM with a correlation coefficient of 0.998 and sensitivity of 426 μA mM⁻¹ cm⁻². The limit of detection of this sensing system was 0.17 μM at the signalto- noise ratio of 3. Additionally, the sensor exhibited long-term stability, good reproducibility, and anti-interference.

Keywords: electrochemical sensor – graphene oxide – magnetic nanocomposites – nitrite

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2015-0099

Chemical Papers 69 (7) 911–920 (2015)