Amine Iron Oxide Nanoparticles (5–30 nm) – Catalog #B2026063

Amine Iron Oxide Nanoparticles (Catalog #B2026063) are colloidal suspensions of superparamagnetic iron oxide nanoparticles (5–30 nm diameter) with primary amine groups grafted onto their surfaces. These particles are supplied as 1 mL of liquid suspension and are widely used in biomedical and research applications that exploit both the magnetic and surface-reactive properties of functionalized iron oxide.

Scientific Overview

Iron oxide nanoparticles are composed of Fe₃O₄ or γ-Fe₂O₃ and exhibit superparamagnetic behavior: they acquire a magnetic moment when exposed to an external field but return to zero magnetization when the field is removed. This prevents aggregation in the absence of a field while allowing rapid magnetic separation when needed. The amine surface coating is introduced via silane chemistry or polymer coating to enable covalent bioconjugation. Amine groups are nucleophilic and can be coupled to carboxyl groups using carbodiimides (EDC/NHS), to aldehyde groups via reductive amination, or to maleimides and other activated esters.

Iron oxide nanoparticles have been extensively studied for applications spanning magnetic resonance imaging, magnetic cell separation, enzyme immobilization, and magnetic immunoassays. Surface functionalization—particularly with amine groups—is critical to directing the particles' behavior in biological systems and enabling bioconjugation strategies tailored to specific applications.

Key applications include:

• Magnetic protein and antibody immobilization for immunoassays and affinity purification
• Enzyme immobilization and biocatalysis with magnetic recovery
• Rapid magnetic cell and bacterial separation in diagnostic assays
• Bioconjugation via covalent attachment of targeting molecules, aptamers, or peptides
• Magnetic drug delivery and cell labeling

Usage & Handling Guidance

Store the suspension at 2–8°C. Sonicate or vortex gently before use to ensure uniform dispersion. Avoid prolonged storage without agitation to prevent settling. Protect from strong magnetic fields during storage.

• Bioconjugation: The amine groups are stable and reactive. Use standard amine-to-carboxyl or amine-to-aldehyde cross-linking chemistry with commercial kits (EDC/NHS for carboxyl coupling, reductive amination for aldehyde coupling).
• Magnetic separation: Apply 0.5–1 minute of magnetic field separation; longer times can cause irreversible particle settling.
• Concentration and aggregation: Particles are stable in aqueous suspension at working concentrations. Avoid extended dilution beyond manufacturer recommendations, which may promote aggregation.
• Protein binding capacity: Request a COA/TDS for the lot-specific binding capacity and saturation conditions.

What You Get

• 1 mL of amine-coated iron oxide nanoparticles (5–30 nm), supplied as liquid suspension
• Superparamagnetic particles with rapid magnetic response
• Reactive amine surface for covalent bioconjugation
• For research use only (RUO)

Why Researchers Choose It

• Amine surface enables straightforward covalent attachment of biomolecules without additional chemistry
• Superparamagnetic behavior allows rapid, field-driven separation without aggregation
• Nanoparticle size (5–30 nm) enables deep tissue penetration in cell-based and diagnostic assays
• Decades of literature demonstrating stable bioconjugates and reliable magnetic recovery
• Ready-to-use liquid suspension—no lengthy synthesis or coating steps required

Frequently Asked Questions (FAQ)

• What are the particles made of?
  Iron oxide (Fe₃O₄ or γ-Fe₂O₃) with an amine-coated surface layer.
• How do I attach proteins or antibodies to these particles?
  Use amine-to-carboxyl cross-linking with EDC/NHS, or use amine-specific reagents. Request a COA/TDS for recommended starting concentrations and protocols.
• Are the particles magnetic enough for separation?
  Yes. They respond rapidly to 0.5–1 Tesla fields commonly used in clinical and research magnetic separation devices.
• Can I store them long-term?
  Store at 2–8°C in the original container. Sonicate before each use to resuspend. Shelf life depends on the lot; consult the label or request a COA.
• What if the particles start to aggregate?
  Gentle sonication usually restores suspension. If aggregation persists, the suspension may have exceeded its shelf life; contact us for a replacement lot.

References

• Li Y, Wu W, Liu Q, Wu Q, Ren P, Xi X, Liu H, Zhao J, Zhang W, Wang Z, Lv Y, Tian B, Sun S, Cui J, Zhao Y, Wu J, Gao M, Chen F. Specific surface-modified iron oxide nanoparticles trigger complement-dependent innate and adaptive antileukaemia immunity. Nat Commun. 2024;15(1):10400.
• Chang YK, Liu YP, Ho JH, Hsu SC, Lee OK. Amine-surface-modified superparamagnetic iron oxide nanoparticles interfere with differentiation of human mesenchymal stem cells. J Orthop Res. 2012;30(9):1499-506.
• Hola K, Markova Z, Zoppellaro G, Tucek J, Zboril R. Tailored functionalization of iron oxide nanoparticles for MRI, drug delivery, magnetic separation and immobilization of biosubstances. Biotechnol Adv. 2015;33(6 Pt 2):1162-76.
• Yuan Y, Rende D, Altan CL, Bucak S, Ozisik R, Borca-Tasciuc DA. Effect of surface modification on magnetization of iron oxide nanoparticle colloids. Langmuir. 2012;28(36):13051-9.