Electrochemical sensing platform based on Schiff-base cobalt(ii)/single-walled carbon nanohorns complexes system

Abstract

Single-walled carbon nanohorns (SWNHs), distinguished by their high purity and unique structure, were noncovalently functionalized with Schiff-base cobalt(II) (Co-salen) for the first time. Cyclic voltammogram of Co-salen/SWNHs display a pair of redox peaks with a formal potential of +0.15 V in 0.1 M phosphate buffer solution (pH 7.0). A novel bifunctional electrochemical sensor for hydrazine oxidation and hydrogen peroxide reduction are presented based on the composite modified electrode. Using amperometry, the linear relationship of hydrazine was found to be in the range from 1 to 96 μM with a sensitivity of 2.4 μA mM⁻¹, the detection limit is 0.1 μM (S/N = 3). The linear relationship of hydrogen peroxide is in the range from 50 to 4600 μM with a sensitivity of 1.8 μA mM⁻¹, the detection limit is 10 μM (S/N = 3). The hybrid material provides a good electrochemical sensing platform and has potential applications in environment analysis and biosensors.