Abstract

ELECTROOXIDATION; STADNIK, Andreia; MARIANI, Filipe Q.  and  ANAISSI, Fauze J.. Effects of precursor salt on colloidal cobalt oxyhydroxides composition and its application in non-enzymatic glucose. S.Afr.j.chem. (Online) [online]. 2017, vol.70, pp.137-144. ISSN 1996-840X.  http://dx.doi.org/10.17159/0379-4350/2017/v70a20.

Colloidal cobalt oxyhydroxide [CoO(OH)] has been prepared from precursors cobalt acetate and cobalt nitrate. The cobalt colloids (Co.Acetate and Co.Nitrate) were characterized by simultaneous thermogravimetric/differential thermal analysis, scanning electron microscopy with energy-dispersive X-ray spectroscopy, Fourier transform infrared and electronic spectroscopy. Characterization data indicated the presence of counter ions (CH₃COO^- and NO₃^-), likely intercalated within the structure of the colloidal cobalt. The platinum working electrode chemically modified with cobalt colloid was studied by cyclic voltammetry in alkaline solution [0.5 M, NaOH], which revealed differences in the reproducibility and stability of the electroactive material. The colloidal Co.Nitrate modified electrode was applied to the non-enzymatic glucose (Glu) electrooxidation in the concentration range from 7.2 to 21.9 X 10⁸ mol L^-1. The limits of detection (5.87 X 10 ⁸ mol L^-1) and quantitation (1.96 X 10 ⁷ mol L^-1) calculated suggest that colloidal Co.Nitrate has the potential to be used as a sensor for low glucose concentration.

Keywords : Salt inorganic; colloidal cobalt; electrooxidation; low glucose concentration.

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