Cerium oxide nanoparticle: a remarkably versatile rare earth nanomaterial for biological applications

et al. 2015

NPG Asia Mater

The fabrication of multi-component hybrid nanostructures is of vital importance because their two-phase interface could provide a rich environment for redox reactions, which are beneficial for enhancing catalytic performance. Inspired by the above consideration, strongly coupled Cu 2 O@CeO 2 core@shell nanostructures have been successfully prepared via a non-organic and clean aqueous route without using any organic additive. In this process, an auto-catalytic redox reaction occurred on the two-phase interface, followed by a triggered self-assembly process. Additionally, the size, morphology and composition of the as-obtained nanostructures can be tuned well by varying the reaction temperature, as well as the species and the amount of Cu precursors. The catalytic tests for peroxidase-like activity and CO oxidation have been conducted in detail, and the results confirm a strong synergistic effect at the interface sites between the CeO 2 and Cu 2 O components.

Section: Catalytic Testmentioning

confidence: 99%

Clean synthesis of Cu2O@CeO2 core@shell nanocubes with highly active interface

Wang

et al. 2015

NPG Asia Mater

“…[4][5][6] With high biocompatibility, nanoceria is also an attractive material for various biological applications. 2,4 For example, it was reported that nanoceria can scavenge reactive oxygen species (ROS) in living systems with superoxide dismutase and catalase-like activities. 2,[7][8][9] In a few cases, nanoceria protected cells from oxidative stress induced by ROS or radiation.…”

Section: Introductionmentioning

confidence: 99%

“…2,4 For example, it was reported that nanoceria can scavenge reactive oxygen species (ROS) in living systems with superoxide dismutase and catalase-like activities. 2,[7][8][9] In a few cases, nanoceria protected cells from oxidative stress induced by ROS or radiation. [10][11][12][13][14] It was also reported that nanoceria protects normal cells but not cancer cells.…”

Section: Introductionmentioning

confidence: 99%

Adsorption of Nanoceria by Phosphocholine Liposomes

2016

Langmuir

Nanoceria (CeO2 nanoparticle) possesses a number of enzyme-like activities. In particular, it scavenges reactive oxygen species (ROS) leading in vitro and in vivo anti-oxidation studies. An important aspect of fundamental physical understanding is its interaction with lipid membranes, the man component of the cell membrane. In this work, adsorption of nanoceria onto phosphocholine (PC) liposomes was performed. PC lipids are the main constituent of the cell outer membrane. Using fluorescence quenching assay, nanoceria adsorption isotherm was determined at various pH's and ionic strengths. A non-Langmuir isotherm occurred at pH 4.0 due to lateral electrostatic repulsion among adsorbed cationic nanoceria. The phosphate group in the PC lipid is mainly responsible for the interaction, and adsorbed nanoceria can be displaced by free inorganic phosphate. The tendency of the system to form large aggregates is a function of pH and the concentration of nanoceria, attributable to nanoceria being positively charged at pH 4 and neural at physiological pH. Calcein leakage test indicates that nanoceria induces liposome leakage due to transient lipid phase transition, and cryo-TEM indicates that the overall shape of the liposome is retained although deformation is still observed. This study provides fundamental biointerfacial information at a molecular level regarding the interaction of nanoceria and model cell membranes.3

“…In the past decade, gold nanoparticles (AuNPs) [4][5][6][7], magnetic iron oxide NPs [8], and cerium oxide NPs (nanoceria) have been reported to mimic various enzymes [9][10][11][12][13][14][15][16]. Oxidation of glucose by AuNPs was first reported by Comotti et al in 2004 [4].…”

Section: Introductionmentioning

confidence: 99%

Characterization of glucose oxidation by gold nanoparticles using nanoceria

Lang

Journal of Colloid and Interface Science

2014

Abstract.Gold nanoparticles (AuNPs) can oxidize glucose, producing hydrogen peroxide and gluconic acid, which are the same products as those generated by glucose oxidase (GOx). In this regard, AuNPs are a nanozyme. Herein, a new colorimetric method is developed to understand the surface chemistry of gold nanoparticles for this oxidation reaction. The color of nanoceria is changed to yellow by the hydrogen peroxide generated glucose oxidation. Using this assay, we find that adsorption of small molecules such as citrate does not deactivate AuNPs, while adsorption of polymers including serum proteins and high molecular weight polyethylene glycol inhibits glucose oxidation. In addition to glucose, AuNPs can also oxidize galactose. Therefore, this reaction is unlikely to be directly useful for glucose detection for biomedical applications. On the other hand, AuNPs might serve as a general oxidase for a broad range of substrates. The glucose oxidation reaction is slower at lower pH. Since the reaction generates an acid product, glucose oxidation becomes slower as the reaction proceeds. The effects of temperature, AuNP size, and reaction kinetics have been systematically studied. This work provides new insights regarding the surface chemistry of AuNPs as a nanozyme.3