Electrocatalysis and sensitive determination of Sudan I at the single-walled carbon nanotubes and iron(III)-porphyrin modified glassy carbon electrodes

Iron-porphyrin (5,10,15,20-tetraphenyl-21H, 23H-porphine iron(III) chloride) was used in combination with single-wall carbon nanotubes (SWNTs) to modify a glassy carbon electrode (GCE). The electrochemical behavior of Sudan I on the iron-porphyrin-SWNT-DMF (N,N-dimethylformamide) modified GCE was studied by the cyclic voltammetry and square wave voltammetry. In pH 7.0 Tris-HCl buffers, Sudan I has a sensitive catalytic reduction peak at -0.08 Von the iron-porphyrin-SWNT-DMF modified GCE. Using square wave voltammetry, the linear relationship of Sudan I is 5.03 x 10(-8) mol L-2.01 x 10(-6) mol L-1 with the tropics equation: Delta(ip) = 3.40C + 3.43 x 10(-6), and the detection limit is 1 x 10(-8) mol L-1. And the iron-porphyrin-SWNT-DMF modified GCE was applied successfully in the determination of Sudan I in real samples. (C) 2010 Elsevier Ltd. All rights reserved.