Cerium Oxide Nanoparticles - BioReagent,1 mg/mL, dispersion solvent: ultrapure water, particle size: 2~5 nm, Surface modification: PAA

Cat. No.: C1523392

GRADE & PURITY BioReagent, 1 mg/mL, dispersion solvent: ultrapure water, particle size: 2~5 nm, Surface modification: PAA

Storage

Store at 2-8°C

Shipped In

Wet ice

Vue d’ensemble

Cerium oxide nanoparticles possess broad-spectrum antioxidant activity and can scavenge free radicals. They exhibit enzyme-mimetic catalytic activities, such as superoxide dismutase (SOD) and catalase. 

Ingredients	Cerium oxide nanoparticles, purified water
Concentration	1 mg/mL
Particle size	2~5 nm
Surface modification	Polyacrylic Acid
Color	Light yellow
Storage conditions	Desiccated, 4℃

Figure 1: TEM image of cerium oxide nanoparticles

Figure 2: Color development of TMB induced by cerium oxide nanoparticles

Figure 3: Rapid oxygen release from H₂O₂ induced by cerium oxide nanoparticles

Specifications

Spécifications et pureté

BioReagent,1 mg/mL, dispersion solvent: ultrapure water, particle size: 2~5 nm, Surface modification: PAA

Stabilité et stockage

Store at 2-8℃ long term (36 months). Desiccated. Do not freeze.

Conditions de stockage de stockage

Store at 2-8°C

Expédié en

Wet ice

Ce produit nécessite l'expédition en chaîne froide. Les services terrestres et autres services économiques ne sont pas disponibles.

Grade

BioReagent

Product Line

Produits biologiques

Application Protocols

No item-specific, validated application protocols are provided for this product; Not specified for this item. Below are general, non-binding procedures to help initiate experiments—adjust to your needs and consult the CoA/Spec Sheet.

• Preparing an aqueous dispersion (general):

  1. Bring material to 2–8 °C working area. Mix by gentle inversion. If supplied as powder, add measured DI water to desired solids (e.g., 0.1–5 wt%).
  2. Sonicate in a bath (5–15 min) or with a probe (1–3 min total pulse time) while cooling to avoid heating.
  3. Adjust pH to target value away from the isoelectric point; verify stability by DLS/turbidity.

• Nanozyme assay setup (general):

  • Prepare matched blanks: buffer only, substrate only, nanoparticle only.
  • Keep ionic strength low; pre-equilibrate nanoparticles in buffer for 15–30 min.
  • Monitor reaction by UV–Vis or dissolved oxygen; account for light scattering/background.

• Catalyst ink for coatings (general):

  • Disperse nanoparticles in ethanol/water with small amounts of binder (e.g., PVP) if compatible with your application.
  • Sonicate and cast/spin onto substrates; dry at ambient or mild heat. Sinter only if your use requires high-temperature activation.

Note: Filtration through 0.22–0.45 µm membranes can partially remove nanoparticles; if sterility is required, consider aseptic technique instead of terminal filtration.

Biological Roles

Item-specific biological testing data are not provided for this product; Not specified for this item. The following summarizes general, literature-reported behaviors of cerium oxide nanoparticles in biological and biochemical research (no clinical or therapeutic claims implied).

• Redox modulation: Surface Ce3+/Ce4+ sites and oxygen vacancies enable catalytic disproportionation of reactive oxygen species (ROS) such as superoxide and decomposition of hydrogen peroxide. Activity depends on particle size, Ce3+ fraction, surface coatings, and environment (pH, ionic strength).
• Enzyme-mimetic (nanozyme) functions in vitro: SOD-like and catalase-like activities have been reported in buffer systems. Peroxidase-like reactions can be observed in the presence of substrates such as TMB/ABTS in acidic media.
• Protein and biomolecule interactions: Ceria surfaces adsorb proteins, phosphates, and carboxylates, forming coronas that modulate dispersion, cellular interactions, and measured activities. Adsorption can occlude or create active sites.
• Fluorescence/quenching: Ceria can quench fluorophores and scatter light, influencing optical assays; careful controls and blank corrections are required.
• Toxicology context: Reported biological responses vary with synthesis route, stabilizer, contaminant metals, dose, and exposure time. Rigorous characterization (DLS/TEM, zeta potential, ICP) is essential to interpret outcomes.

Practical guidance:

• Use nanoparticle-free controls and, where applicable, enzyme controls to benchmark activity.
• Validate dispersion state in the assay matrix; aggregation often shifts outcomes more than dose alone.
• For cell-free biochemical work, pre-equilibrate particles in assay buffer to stabilize corona formation before measurements.

Buffer Applications

Ceria nanoparticles are not conventional buffering agents. However, they are frequently used within buffered systems for biochemical or catalytic studies. Item-specific buffer compatibility is Not specified for this item; consult the CoA/Spec Sheet.

General guidance (literature/experience):

• pH influence: Ceria’s surface charge and activity vary with pH; many nanozyme assays use acetate (pH 3–5), phosphate (pH 6–7.4), or Tris/HEPES (pH 7–8.5). Verify that the buffer does not strongly complex cerium or cause aggregation.
• Phosphate effects: Phosphate buffers can adsorb onto ceria, altering redox properties and sometimes inhibiting activity. If inhibition is suspected, consider HEPES, MES, or borate as alternatives and compare results.
• Ionic strength: High salt promotes agglomeration and sedimentation. Work at minimal ionic strength consistent with assay requirements, or introduce steric stabilizers.
• Preparation tips: Equilibrate nanoparticles in the working buffer via gentle mixing and brief sonication. Measure DLS/zeta potential to confirm stability. Filter sterilization may remove nanoparticles; prefer sterile technique over 0.22 µm filtration when particle recovery matters.

Green Alternatives

Ceria nanoparticles are often considered in green chemistry contexts due to their heterogeneous, reusable nature and ability to operate under milder conditions than some homogeneous oxidants. Selection should weigh environmental impact, energy needs, and assay interference.

Comparison of options (literature/general):

• Ceria nanoparticles (CeO2):

  • Pros: Reusable solid; strong redox cycling; function at ambient to moderate temperatures; low vapor pressure/nonvolatile; minimal solvent contamination post-separation.
  • Tradeoffs: Mining/rare-earth footprint; potential ecotoxicity of released nanoparticles; possible interference with redox/ROS bioassays.

• Iron oxide nanoparticles (Fe3O4/γ‑Fe2O3):

  • Pros: Abundant, magnetic separation simplifies recovery; lower criticality metals.
  • Tradeoffs: Different redox potentials; may require peroxides (Fenton-like) leading to radical generation and safety/hazard concerns.

• Manganese dioxide nanoparticles (MnO2):

  • Pros: Effective oxidant and catalase-mimetic in vitro; abundant.
  • Tradeoffs: Can dissolve to Mn2+ under reducing conditions; potential cytotoxicity at higher doses.

• Homogeneous oxidants (e.g., permanganate, chromium(VI), peroxide):

  • Pros: High activity/selectivity in some reactions.
  • Tradeoffs: Stoichiometric waste, higher hazard profiles (Cr(VI) toxicity), and challenging workups.

Greener practice tips:

• Use aqueous dispersions, recover catalyst by centrifugation/filtration, and regenerate via calcination/reduction cycles when appropriate.
• Quantify nanoparticle release and implement capture/reuse; document mass balance and E-factors.
• Consider doped ceria (e.g., Zr, Gd) to lower operating temperatures, reducing energy input—verify with literature and pilot studies.

Pharmaceutical Uses

This product is designated for research use only. It is not an approved active ingredient or excipient. No pharmacopeial monograph applicability or GMP status is provided for this item; Not specified for this item—consult CoA/Spec Sheet if needed.

Context for formulation research (general/literature):

• Ceria nanoparticles are investigated in preclinical research as redox-active components in topical barriers, coatings, and as functional excipients in in vitro models. Such uses remain research-stage and require extensive safety and quality assessments.
• Key considerations for any formulation research:
  • Particle size distribution (primary vs hydrodynamic), zeta potential, agglomeration state in the target vehicle.
  • Surface chemistry: Identity and stability of coatings (e.g., citrate, PEG) and their impact on compatibility with excipients, pH, and ionic strength.
  • Extractables/leachables and residual synthesis byproducts that may impact safety or stability.
  • Optical properties and color that can affect product aesthetics and UV protection in R&D prototypes.
• Regulatory note: Transition from research to regulated applications would require detailed CMC documentation, impurity profiles, and standardized manufacturing controls—outside the scope of this product.

Physical Properties

Item-specific physicochemical specifications (e.g., particle size, surface area, zeta potential, dispersant/ligand, solids content): Not specified for this item; refer to CoA/Spec Sheet.

General/literature properties for bulk cerium(IV) oxide (ceria):

• Appearance: pale yellow to off‑white solid powder (literature; nanoparticle dispersions may appear translucent to opalescent).
• Density (bulk): ~7.1–7.3 g/cm³ (literature). Effective apparent density in dispersions depends on solids loading and stabilizer.
• Melting point: ~2400–2600 °C (decomposes/sinters; literature).
• Solubility: Insoluble in water and common organic solvents; dispersible as colloids with suitable pH/ionic strength or surface ligands (literature). Slowly dissolves under strongly acidic conditions to Ce3+ salts.
• Refractive index (bulk): n ≈ 2.2–2.3 (visible; literature), basis of optical applications; nanoscale values depend on size/porosity.
• Band gap: indirect ~3.0–3.2 eV (literature), enabling UV absorption/photocatalysis.
• Surface chemistry in water (general): Hydroxylated surfaces; isoelectric point commonly reported near pH 6–8 depending on synthesis history and adsorbates (literature). Zeta potential and hydrodynamic size are sensitive to pH and ionic strength.

Transport/dispersion notes (general):

• Nanoparticles may agglomerate in high-ionic-strength buffers or near the isoelectric point; sonication and low electrolyte levels improve dispersion stability.
• Avoid drying/rehydration cycles if a specific dispersion state is required (consult item CoA for any stabilizer present).

Quality and Grades

• Item-specific grade: BioReagent (as provided). No additional specifications (particle size distribution, endotoxin, bioburden, stabilizer, trace metal limits) are listed here; Not specified for this item—refer to CoA/Spec Sheet for definitive values.

What BioReagent grade generally implies (general guidance):

• Intended for research and laboratory applications, including biochemical assays and cell-free systems. Typical expectations may include tighter controls on adventitious contaminants that could interfere with biological assays (e.g., lower residual organics or ionic contaminants) compared with technical grade. Exact acceptance criteria vary by manufacturer and lot.
• UV-Vis background, redox activity, and trace transition metals can strongly influence biological readouts with ceria; vendors may control synthesis/cleaning to minimize assay interference. Confirm by reviewing CoA.

Stabilizers/coatings (general considerations):

• Some ceria nanoparticle products are supplied with polymer or small-molecule stabilizers (e.g., citrate, PVP, PEG) to improve colloidal stability or biocompatibility. For this item, the presence and identity of any stabilizer are Not specified—review CoA.

Release documents recommended for QC review:

• Certificate of Analysis (lot-specific): particle size metrics (TEM/DLS), solids content, pH, conductivity, stabilizer identity, endotoxin/bioburden (if applicable), residual ions, assay interferences.
• Specification sheet: storage, shelf life, and acceptable ranges for key properties.

Note: This product is for research use only; not for human or animal therapeutic or diagnostic use.

Reaction and Applications

Manufacturer-provided application list: Not specified for this item.

General research applications of cerium oxide nanoparticles (literature):

• Redox catalysis and oxygen storage: The Ce4+/Ce3+ couple and mobile lattice oxygen enable oxidation reactions (e.g., CO oxidation, soot oxidation, VOC abatement) and synergistic effects when combined with noble metals (Pt, Au, Pd) in heterogeneous catalysis.
• Nanozyme activity: Ceria NPs exhibit superoxide dismutase- and catalase-mimetic activities in vitro, attributed to surface Ce3+ sites and oxygen vacancies. These properties underpin use in ROS/RNS scavenging studies and assay development (no clinical claims implied).
• Photocatalysis/UV screening: Band gap ~3.0–3.2 eV allows UV absorption; used in UV-filter research, photodegradation of dyes, and photo-redox systems.
• Polishing and CMP research: High hardness and chemical activity toward silica/glass interfaces make ceria NPs useful in model chemical–mechanical planarization studies.
• Electrochemical systems: Used in solid oxide fuel cell electrolytes/electrolyte modifiers (e.g., Gd-doped ceria) and as redox-active additives in sensors.

Practical tips (general):

• Surface state matters: Higher Ce3+ fraction increases radical scavenging and certain catalytic rates; controlled reduction (e.g., H2 pretreatment) can tune activity.
• Support/ligand effects: Anchoring Au/Pt on ceria dramatically changes activity/selectivity; ligands can block or direct active sites.
• Avoid inadvertent catalysis: Ceria can decompose H2O2 and alter redox-sensitive assays—include appropriate nanoparticle-free controls.

Reaction Conditions

Item-specific reaction condition recommendations are not provided for this product. The following are literature/general guidance for ceria-based nanocatalysts; optimize for your system.

• Aerobic alcohol oxidation (Au/CeO2):

  • Solvent: Toluene or solvent-free; O2 or air at 1–10 bar.
  • Temperature: 60–120 °C; Time: 2–24 h.
  • Notes: Pretreat catalyst under O2 at 200–300 °C; avoid base for selective aldehyde formation.

• CO oxidation (CeO2 or Pt/CeO2):

  • Gas-phase; Ambient to 200 °C depending on catalyst dispersion.
  • Notes: Higher Ce3+ fraction and small particle size lower light-off temperature.

• Knoevenagel condensation (CeO2 basic sites):

  • Solvent: Ethanol, water/ethanol, or solvent-free.
  • Temperature: RT–80 °C; Base-free conditions often feasible.

• Peroxide decomposition (catalase-mimetic, in vitro):

  • Medium: Aqueous buffer; pH 7–8 typically increases catalase-like behavior.
  • Notes: Monitor O2 evolution; nanoparticles alter assay kinetics versus enzymes.

• Cross-coupling with Pd/CeO2:

  • Solvent: Aqueous ethanol or polar aprotic (DMF, dioxane).
  • Base: K2CO3, K3PO4.
  • Temperature: 60–100 °C; Time: 2–12 h.
  • Notes: Strong metal–support interactions can reduce Pd leaching; confirm by ICP.

General precautions:

• Standardize pretreatment (e.g., 300–500 °C calcination, 200–400 °C H2 reduction) to reproducible surface states; nanoparticles for bioassays should not be calcined—use mild thermal/vacuum treatments only.
• Verify dispersion and surface area before/after reactions; sintering deactivates catalysts.
• For aqueous nanozyme assays, include nanoparticle-only and substrate-only controls to identify artifactual signals.

Safety and Handling

Authoritative safety classification for this specific item (GHS signal word, hazard statements, pictograms): Not specified for this item; consult the SDS.

General nanomaterial safety guidance (literature/industry best practice):

• Potential hazards: Inhalation of nanoscale particulates can pose respiratory hazards; dry powders may cause mechanical eye/skin irritation. For aqueous dispersions, aspiration risk is reduced but aerosol generation should be minimized.
• PPE: Wear lab coat, safety glasses or face shield, and appropriate gloves (e.g., nitrile). Use a NIOSH-approved respirator if handling dry powders outside a certified fume hood or if aerosols may form.
• Engineering controls: Handle powders in a fume hood or ventilated enclosure; for dispersions, work in a hood to avoid aerosolization. Use closed containers and secondary containment.
• Incompatibilities (general): Strong acids can dissolve ceria to cerous salts; avoid contact with strong reducing agents at elevated temperature. Avoid mixing with concentrated hydrogen peroxide in confined systems (oxygen evolution possible upon catalytic decomposition).
• First aid (general):
  • Inhalation: Move to fresh air; seek medical attention for persistent symptoms.
  • Skin/eye contact: Rinse with water for at least 15 minutes; remove contaminated clothing; seek medical attention as needed.
  • Ingestion: Rinse mouth; do not induce vomiting; get medical advice.
• Fire/reactivity: Noncombustible inorganic solid; may catalyze oxidation of organics at elevated temperature. Use suitable extinguishing media for surrounding fire.
• Waste: Collect as hazardous laboratory waste; do not discharge nanoparticle dispersions to drains. Follow institutional and local regulations.
• Always defer to the product-specific SDS for authoritative information.

Solvent Selection

For cerium oxide nanoparticles, the “solvent” is the dispersion medium. Item-specific medium (water, buffer, alcohols) and stabilizer are Not specified for this item; refer to CoA/Spec Sheet.

General guidance for dispersing ceria nanoparticles (literature/experience):

• Aqueous media: Deionized water at low ionic strength is preferred for initial dispersion. Adjust pH away from the isoelectric point (often reported near pH 6–8) to enhance electrostatic stabilization (e.g., mildly acidic pH 4–5 or basic pH 9–10 depending on surface chemistry).
• Buffers: Phosphate and other multivalent anions can adsorb to ceria and may induce aggregation or alter surface redox. Use dilute buffers and verify colloidal stability by DLS or turbidity.
• Organic media: Short-chain alcohols (ethanol, isopropanol) can be used to exchange solvent or co-disperse with water; pure organic solvents generally require surface modification (e.g., ligand exchange) for stability.
• Additives: Dispersants such as citrate, EDTA (complexing), or polymers (PVP, PEG) may improve stability and control surface charge; selection must be compatible with downstream assays.

Comparison (general):

• Water: Highest biocompatibility, minimal background; may require pH control to avoid aggregation.
• PBS/physiological saline: Convenient for bioassays but higher ionic strength—aggregation risk; consider lower salt or add steric stabilizer.
• Ethanol/water mixtures: Useful for coatings and catalyst ink formulation; drying behavior favorable for films.

Practical tips:

• Sonicate with a probe or bath (avoid overheating). Filter through 0.45 µm only if aggregation is acceptable; nanoparticles may be retained by small-pore membranes.

Storage and Reconstitution

• Storage conditions (item-specific): Store at 2–8 °C (as provided). Avoid freezing unless the CoA/Spec Sheet explicitly permits it. Maintain containers tightly closed to prevent evaporation and concentration changes.
• Shipping (item-specific): Shipped on wet ice.
• Shelf life: Not specified for this item; refer to CoA/Spec Sheet.

General guidance for nanoparticle stability:

• If supplied as an aqueous dispersion: Do not allow to dry; drying/rehydration can irreversibly change size and activity. Mix by gentle inversion or low-speed vortexing before use. If sediment forms over time, redisperse by brief sonication while keeping temperature low.
• If supplied as a dry powder: Reconstitute in DI water or a specified buffer. Start at low ionic strength, adjust pH to promote electrostatic stabilization, and consider adding a compatible dispersant (e.g., citrate or polymer) as appropriate for your application.
• Freeze–thaw: Avoid repeated freeze–thaw cycles; they can promote aggregation. If freezing is unavoidable, add cryoprotectants compatible with your work and verify dispersion after thawing.
• Light/contamination: Store protected from excessive light and dust. Use clean plasticware or glassware; some proteins/polymers can adsorb to ceria and alter performance.
• Documentation: Record lot number, storage history, and any pH/additives introduced upon reconstitution to ensure reproducibility across experiments.

Research Use Note: For research use only.

Structure and Identity

Cerium oxide nanoparticles are nanoscale particles of the inorganic ceramic cerium(IV) oxide (ceria), an f‑block metal oxide with mixed Ce4+/Ce3+ surface states and oxygen vacancies that underpin its redox activity.

• Item-specific identifiers:
  • CAS, CID, InChIKey, SMILES: Not specified for this item; refer to CoA/Spec Sheet.
• Core composition (literature/general):
  • Molecular formula (ceria): CeO2 (literature)
  • Empirical unit mass (CeO2): ~172.12 g/mol (Ce 140.12 + 2×16.00) (literature)
  • Common names: ceria, cerium(IV) oxide (literature)
• Structural features (general description):
  • Crystal structure: Fluorite-type Fm3̅m; Ce4+ cations in fcc lattice with O2− in tetrahedral sites; oxygen vacancies readily form at surfaces (literature).
  • Surface chemistry: Mixed Ce3+/Ce4+ redox couple, coordinatively unsaturated surface cerium, labile lattice oxygen; hydroxylation in aqueous media (literature).
  • Particle architecture: Nanoparticulate domains (primary size and any coating/ligand are not specified for this item; refer to CoA/Spec Sheet). Aggregates/agglomerates may form depending on dispersion conditions.
• 2D depiction in words (general):
  • In a 2D schematic, ceria is represented as repeating Ce–O lattice units; at the nanoparticle surface, oxygen vacancies (□) and hydroxyls (–OH) are depicted, with dynamic Ce4+ ⇄ Ce3+ centers facilitating redox reactions (literature).

Synthetic Utility

While cerium oxide nanoparticles are not molecular reagents, they serve as versatile heterogeneous catalysts and catalyst supports in synthetic chemistry and materials processing. Item-specific catalytic benchmarking is Not specified for this item; refer to CoA/Spec Sheet.

General utilities (literature):

• Oxidations: Ceria promotes aerobic oxidation of alcohols, oxidative dehydrogenations, and halogen-free oxidative couplings, often enhanced by Au/Pd/Pt decoration or by doping (Zr, Cu, Mn) to increase oxygen vacancy concentration.
• C–C and C–N bond formations: As supports for transition metals (e.g., Pd/CeO2), ceria enhances cross-coupling (Suzuki–Miyaura, Heck) via strong metal–support interactions, improving activity at lower metal loadings.
• Reductive transformations: Under H2, ceria participates in hydrogenation and transfer hydrogenation by activating H–H or O–H bonds at metal–ceria interfaces.
• Acid–base catalysis: Lewis acidity of Ce4+ and basic surface oxygen enable cascade reactions (e.g., Knoevenagel condensations followed by cyclizations) on the same surface.
• Photocatalysis: UV-driven redox with dye degradation and selective oxidations; synergistic with TiO2 or graphitic carbon nitride in composites.

Practical notes:

• Pretreatment history (calcination/reduction) dictates Ce3+/vacancy content; standardize to obtain reproducible outcomes.
• Avoid poisoning by phosphates, sulfur, or chlorides for oxidation catalysis; prewash or regenerate as needed.
• Separate and recycle by centrifugation or filtration; monitor activity loss and sintering via TEM/XRD and XPS for surface state.

Target Specificity

Not applicable. This product is an inorganic nanoparticle material, not an antibody or affinity reagent. No antigen/epitope, clone, isotype, or species reactivity information applies.