{"product_id":"carboxyl-iron-oxide-nanoparticles-5-30-nm","title":"Carboxyl Iron Oxide Nanoparticles (5–30 nm)","description":"\u003cdiv style=\"max-width:1400px; margin:0 auto; padding:40px 20px; font-family:'Open Sans',sans-serif; font-weight:300; background:#fff; color:#333; font-size:0.95rem; box-sizing:border-box;\"\u003e\n  \u003cdiv style=\"display:flex; flex-direction:column; gap:20px;\"\u003e\n\u003ch2 style=\"margin:0; font-weight:600;\"\u003eCarboxyl Iron Oxide Nanoparticles (5–30 nm) – Catalog #B2026060\u003c\/h2\u003e\n\u003cp\u003eCarboxyl-functionalized iron oxide nanoparticles unite two powerful capabilities: a magnetic core for rapid separation and a reactive carboxyl surface for covalent coupling. These 5–30 nm particles are supplied as a stable liquid suspension, making them immediately useful for immunoprecipitation, affinity capture, and targeted purification. The small size ensures rapid sedimentation in a magnetic field and rapid kinetics of binding and release. The carboxyl groups enable direct coupling of antibodies, streptavidin, biotin, aptamers, and other targeting ligands via standard carbodiimide (EDC) or carbodiimide\/sulfo-NHS chemistry.\u003c\/p\u003e\n\u003cdiv style=\"overflow-x:auto; max-width:100%; margin-bottom:20px;\"\u003e\n\u003ctable style=\"width:100%; max-width:640px; border-collapse:collapse;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eCatalog Number:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003eB2026060\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eAmount:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003e2 mL\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eParticle Size Range:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003e5–30 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eMaterial:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003eIron Oxide (Fe₃O₄)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eSurface Functionality:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003eCarboxyl groups (–COOH)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eSupplied As:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003eLiquid suspension\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eApplications:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003eMagnetic separation, protein purification, affinity capture, immunoprecipitation, nanoparticle applications\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eStorage:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003e2–8 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eKeywords:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003ecarboxylated iron oxide, carboxyl iron oxide nanoparticles, carboxyl magnetic, Fe3O4, magnetic nanoparticles\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003ch3 style=\"margin-top:30px;\"\u003eScientific Overview\u003c\/h3\u003e\n\u003cp\u003eIron oxide nanoparticles, particularly magnetite (Fe₃O₄), possess superparamagnetic properties at sizes below ~100 nm. This means they develop strong magnetic moments in the presence of an external magnetic field but retain no residual magnetization when the field is removed. This property enables rapid, reversible capture and release of particle-bound targets, a hallmark advantage over permanent magnets or ferromagnetic particles that can aggregate.\u003c\/p\u003e\n\u003cp\u003eThe carboxyl surface coating provides reactive anchor points for covalent attachment of proteins, peptides, and other molecules. Carboxyl groups are activated via EDC (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide) with or without sulfo-NHS to form reactive O-acylisourea intermediates that readily react with primary amines on proteins. This chemistry is mild, aqueous, and highly reproducible, making it the gold standard for biomolecule attachment to nanoparticles. The small particle size (5–30 nm) maximizes surface area per unit mass and minimizes steric hindrance, supporting high coupling densities and rapid binding kinetics.\u003c\/p\u003e\n\u003cp\u003eKey applications include:\u003c\/p\u003e\n\u003cul style=\"padding-left:20px;\"\u003e\n\u003cli\u003eImmunomagnetic separation: capture antibody-bound cells, pathogens, or proteins from complex mixtures\u003c\/li\u003e\n\u003cli\u003eAffinity purification: isolate His-tagged, biotin-tagged, or antigen-specific proteins without centrifugation tubes or columns\u003c\/li\u003e\n\u003cli\u003eCo-immunoprecipitation: pull down protein–protein complexes using magnetic beads coated with capture antibodies\u003c\/li\u003e\n\u003cli\u003eBiomarker enrichment: isolate rare cells, exosomes, or circulating tumor DNA before downstream analysis\u003c\/li\u003e\n\u003cli\u003eDrug conjugation research: attach small molecules or peptides to a magnetic scaffold for screening or targeted delivery\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"margin-top:30px;\"\u003eUsage \u0026amp; Handling Guidance\u003c\/h3\u003e\n\u003cp\u003eBefore coupling, gently mix the suspension to resuspend any settled particles. For EDC coupling, dilute the nanoparticle suspension in coupling buffer (typically 10 mM MES, pH 4.5–6.5), add EDC and optionally sulfo-NHS, then add your target protein. Incubate 30 minutes to 2 hours at room temperature or 4 °C. Wash by magnetic separation (applying a magnet to the side of the tube) 2–3 times. Coupled particles are then ready for capture experiments or may be stored at 2–8 °C in PBS with a carrier protein (e.g., 0.1% BSA) to prevent aggregation.\u003c\/p\u003e\n\u003cul style=\"padding-left:20px;\"\u003e\n\u003cli\u003eUse a strong permanent magnet (neodymium or samarium-cobalt) held to the outside of the tube for rapid sedimentation\u003c\/li\u003e\n\u003cli\u003eDo not expose to powerful electromagnets or strong static fields for extended periods, as this may cause irreversible aggregation\u003c\/li\u003e\n\u003cli\u003eAlways include a protein carrier (BSA, casein) in long-term storage buffers to prevent non-specific aggregation\u003c\/li\u003e\n\u003cli\u003eMinimize freeze–thaw cycles; store coupled particles in glycerol or ethylene glycol-containing buffers if freezing is necessary\u003c\/li\u003e\n\u003cli\u003eFor removal of excess EDC or coupling reagents, perform 3–5 magnetic washes in 1× PBS before use\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"margin-top:30px;\"\u003eWhat You Get\u003c\/h3\u003e\n\u003cul style=\"padding-left:20px;\"\u003e\n\u003cli\u003e2 mL of carboxyl iron oxide nanoparticle suspension (5–30 nm, in aqueous medium)\u003c\/li\u003e\n\u003cli\u003eParticles ready to couple or use directly in magnetic separation workflows\u003c\/li\u003e\n\u003cli\u003eStorage buffer optimized for stability and minimal aggregation\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"margin-top:30px;\"\u003eWhy Researchers Choose It\u003c\/h3\u003e\n\u003cul style=\"padding-left:20px;\"\u003e\n\u003cli\u003eSuperparamagnetic behavior enables rapid, reversible capture without permanent aggregation\u003c\/li\u003e\n\u003cli\u003eCarboxyl groups allow quick, efficient protein coupling via standard EDC chemistry\u003c\/li\u003e\n\u003cli\u003eSmall particle size (5–30 nm) ensures rapid equilibration and high surface-area-to-volume ratio\u003c\/li\u003e\n\u003cli\u003eLiquid suspension format requires no resuspension; ready to use directly in coupling or capture protocols\u003c\/li\u003e\n\u003cli\u003eNanoparticle scale enables both bulk purification (mL scale) and high-sensitivity detection in analytical workflows\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"margin-top:30px;\"\u003eFrequently Asked Questions (FAQ)\u003c\/h3\u003e\n\u003cul style=\"padding-left:20px;\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eWhat is the typical coupling density?\u003c\/strong\u003e\u003cbr\u003eCoupling density depends on the target protein size, carboxyl group density, and incubation time. Literature reports 100–500 µg of protein per mL of carboxylated nanoparticles, equivalent to ~10⁸–10⁹ protein molecules per particle. Optimization for your protein is recommended.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHow do I prevent non-specific binding?\u003c\/strong\u003e\u003cbr\u003eBlock the nanoparticles post-coupling with a carrier protein (1% BSA, 1% casein, or goat serum) and include detergents (0.01–0.1% Triton X-100 or Tween-20) in wash and incubation buffers. Pre-incubation of coupled particles in blocking buffer for 30 minutes before capture improves specificity.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCan I couple antibodies, aptamers, or other molecules?\u003c\/strong\u003e\u003cbr\u003eYes. Any molecule with a primary amine group (or convertible to one) can be coupled via EDC chemistry. Antibodies, streptavidin, biotin-conjugated ligands, peptides, and DNA aptamers are commonly used. Optimize EDC and target molecule concentrations for your specific application.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHow long do coupled nanoparticles remain stable?\u003c\/strong\u003e\u003cbr\u003eProperly stored coupled particles (2–8 °C, in PBS + 0.1% BSA) typically remain functional for 3–6 months. Storage in glycerol-based buffers can extend stability for longer-term use. Avoid repeated freeze–thaw cycles.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDo I need a special magnet?\u003c\/strong\u003e\u003cbr\u003eA strong permanent neodymium magnet (e.g., 1–2 Tesla field strength) held to the outside of a standard microcentrifuge tube or well plate is sufficient for rapid sedimentation (30 seconds to 2 minutes). Electromagnets or weaker magnets may require longer incubation times.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cdiv style=\"margin-top:20px; font-weight:bold; color:#c8102e;\"\u003eThis product is for Research Use Only (RUO). It is not intended for diagnostic or therapeutic use in humans or animals.\u003c\/div\u003e\n\u003chr\u003e\n\u003ch4\u003eReferences\u003c\/h4\u003e\n\u003cul style=\"padding-left:0; margin:0; list-style:none;\"\u003e\n\u003cli style=\"display:flex; justify-content:space-between; align-items:flex-start; gap:12px; padding:8px 0; border-bottom:1px solid #eee;\"\u003e\n\u003cspan style=\"flex:1;\"\u003e\u003c\/span\u003e\u003ca href=\"https:\/\/doi.org\/10.3390\/ijms23105410\" target=\"_blank\" rel=\"noopener\" style=\"flex-shrink:0; margin-top:2px;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/Reference.png?v=1775409336\" alt=\"Reference\" style=\"height:28px; width:auto;\"\u003e\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli style=\"display:flex; justify-content:space-between; align-items:flex-start; gap:12px; padding:8px 0; border-bottom:1px solid #eee;\"\u003e\n\u003cspan style=\"flex:1;\"\u003e\u003c\/span\u003e\u003ca href=\"https:\/\/doi.org\/10.1007\/978-1-0716-3362-5_8\" target=\"_blank\" rel=\"noopener\" style=\"flex-shrink:0; margin-top:2px;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/Reference.png?v=1775409336\" alt=\"Reference\" style=\"height:28px; width:auto;\"\u003e\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli style=\"display:flex; justify-content:space-between; align-items:flex-start; gap:12px; padding:8px 0; border-bottom:1px solid #eee;\"\u003e\n\u003cspan style=\"flex:1;\"\u003e\u003c\/span\u003e\u003ca href=\"https:\/\/doi.org\/10.1186\/s12951-023-02123-7\" target=\"_blank\" rel=\"noopener\" style=\"flex-shrink:0; margin-top:2px;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/Reference.png?v=1775409336\" alt=\"Reference\" style=\"height:28px; width:auto;\"\u003e\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n  \u003c\/div\u003e\n\u003c\/div\u003e","brand":"Molecular Depot","offers":[{"title":"Default Title","offer_id":52809022898474,"sku":"BTS-B2026060","price":825.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/B2026060-1.png?v=1790859801","url":"https:\/\/bluetigerscientific.com\/products\/carboxyl-iron-oxide-nanoparticles-5-30-nm","provider":"Blue Tiger Scientific","version":"1.0","type":"link"}