Detection of Hydroxyl Radicals Using Cerium Oxide/Graphene Oxide Composite on Prussian Blue

A composite sensor consisting of two separate inorganic layers of Prussian blue (PB) and a composite of cerium oxide nanoparticles (CeNPs) and graphene oxide (GO), is tested with center dot OH radicals. The signals from the interaction between the composite layers and center dot OH radicals are characterized using cyclic voltammetry (CV). The degradation of PB in the presence of H(2)O(2)and center dot OH radicals is observed and its impact on the sensor efficiency is investigated. The results show that the composite sensor differentiates between the solutions with and without center dot OH radicals by the increase of electrochemical redox current in the presence of center dot OH radicals. The redox response shows a linear relation with the concentration of center dot OH radicals where the limit of detection, LOD, is found at 60 mu M (100 mu M without the PB layer). When additional composite layers are applied on the composite sensor to prevent the degradation of PB layer, the PB layer is still observed to be degraded. Furthermore, the sensor conductivity is found to decrease with the additional layers of composite. Although the CeNP/GO/PB composite sensor demonstrates high sensitivity with center dot OH radicals at low concentrations, it can only be used once due to the degradation of PB.