ELECTROCHEMICAL-BEHAVIOR OF TOLUIDINE-BLUE-O COVALENTLY MODIFIED MICROCYLINDER CARBON-FIBER ELECTRODE AND AMPEROMETRIC DETERMINATION OF HEMOGLOBIN IN WHOLE-BLOOD

The hemoglobin concentration in diluted whole blood has been amperomet rically measured using a toluidine blue O covalently modified microcyl inder carbon fiber electrode. The modified electrode was prepared by m odifying the surface of carbon fiber by cyclic voltammetric oxidation to form a lot of -COOH groups, and then covalently linking toluidine b lue O (TBO) by acylation. The surface morphology and stability of the TBO modified electrode are discussed. The electrochemical behaviour of the modified electrode was studied by cyclic voltammetry. The number of H+ participating in the surface electrode process and some kinetic parameters in various pH solutions were determined. The TBO modified m icroelectrode showed significant electrocatalytic activity for the oxi dation of hemoglobin(HB) in pH 5.4 solution. The amperometric response to HE increased linearly with increasing concentration from 8.0x10(-6 ) to 8.0x10(4) M. The obtained HB concentration correlated well with t hat obtained using a reference procedure. Copyright (C) 1996 by Marcel Dekker, Inc.