Retraction Note to: Effect of Urea on the Morphology of Fe 3 O 4 Magnetic Nanoparticles and their Application in Potentiometric Urea Biosensors

The Editor-in-Chief has retracted this article [1] because Figure 4 and Figure 5 appear to show cobalt oxide nanoparticles and not iron oxide nanoparticles as stated in the article. The data reported in this article are therefore unreliable.