title: TiO2@CeOx core-shell nanoparticles as artificial enzymes with peroxidase-like activity.
abstract: The Ce4+↔Ce3+ redox switch is at the basis of an all-inorganic catalytic cycle that is capable of mimicking the activity of several natural redox enzymes. The efficiency of these artificial enzymes (nanozymes) strongly depends on the Ce4+/Ce3+ ratio. By capitalizing on the results obtained on oxide/oxide model systems, we implemented a simple and effective procedure to obtain conformal TiO2@CeOx core-shell nanoparticles whose thickness is controlled with single-layer precision. Since the Ce3+ species are stabilized only at the interface by the electronic hybridization with the TiO2 states, the modulation of the shell thickness offers a simple method to tailor the Ce4+/Ce3+ ratio and therefore the catalytic properties. The activity of these nanoparticles as artificial peroxidase-like enzymes was tested, showing exceptional performances, even better than natural horseradish peroxidase enzyme. The main advantage with respect to other oxide/oxide nanozymes is that our nanoparticles, having a tunable Ce4+/Ce3+ ratio, are efficient already at low H2O2 concentrations.
authors.affiliation: Department of Chemical Sciences, University of Padova , via Marzolo 1, I-35131 Padova, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Artiglia
authors.forename: Stefano
authors.initials: S
authors.lastname: Agnoli
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Paganini
authors.forename: Mattia
authors.initials: M
authors.lastname: Cattelan
authors.forename: Gaetano
authors.initials: G
authors.lastname: Granozzi
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism*; D002384:Catalysis; D002563:Cerium / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000378:metabolism; D006861:Hydrogen Peroxide; D053768:Metal Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D014025:Titanium / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; C009495:titanium dioxide; D002563:Cerium; C030583:ceric oxide; D006861:Hydrogen Peroxide; D014025:Titanium; D006735:Horseradish Peroxidase
keywords: artificial enzyme; cerium oxide; core−shell; interface hybridization; peroxidase; titanium dioxide