In recent years, direct electrochemistry of’ proteins and enzymes is an interest subject because of its potential application in the study of the redox and electron transfer properties of biomolcules [I ,2]. The combination of biological molecules and novel nanomaterials components is of great importance in the processes ol’ developing new nanoscale devices for future biological, medical and electronic applications [3]. Cyclic voltammetry was used for modification of glassy carbon electrode with clectrodeposited cobalt oxide nano particle ,hemoglobine and FAD. Scanning electrom microscopy (SEM), cyclic voltammetry, UV-Visihle spectroscopy technique was used to characterization of modified electrode. Direct electron transfer of hemoglobin and FAD immobilized onto cobalt oxide nanoparticles have been investigated. FAD/cobalt oxide and Hb/cobalt oxide exhibited single redox couples at -0.435 and -0.45 in p1-I 7 phosphate buffer solution which corresponded to FAD and Hemoglobin active sites. I-ugh surface coverage and heterogeneous electron transfer rate good electrocatalytic effect of two type modified electrode are indicating high enzyme loading and great facilitation of the electron transfer between biomoleculec (FAD,Hb) and cobalt oxide nanoparticles. Short response time, good stability and reproducibility of this sensor are advantages of the proposed sensors.
