Method and electrochemical sensing strip with screen-printed three electrodes for determining concentration of dissolved oxygen in a solution

摘要

A new electrochemical method for determining dissolved oxygen concentration is developed. It employs cobalt based oxide or complex to modify a conductive electrode surface. This method can be applied to determine dissolved oxygen in regard to medical and environmental demands. The chemical formula of the cobalt based oxide or complexes can be shown as Co_xO_y or Co_aL_b. Both "x" and "a" represent the number of cobalt atom; while "y" and "b" represent the number of oxygen atom and the number of coordinating ligand, respectively. For instance, the best known example of cobalt oxide is CO₃O₄, and the best known examples of cobalt complexes are cobalt phthalocyanine (CoPC) and cyanocobalamin (vitamin B₁₂), or other macrocyclic complexes with a metallic nucleus of cobalt. The present invention determines the concentration of dissolved oxygen in solution in potentiostatic mode with three electrodes. As a result, the dissolved oxygen can be determined between 0.0V and -0.3V vs. Ag/AgCl, thereby significantly reducing the interferences from the easily oxidized compounds in water solutions.