Synthesis, characterization and applications of maghemite beads functionalized with rabbit antibodies

Abstract

Magnetic nanoparticles (NPs) have attracted great attention owing to their applications in the biomedical field. In the present work, maghemite (γFeO) NPs of 6.5 nm were prepared using a sonochemical method and used to prepare magnetic beads through silanization with 3-aminopropyltrimethoxysilane (APTS). Subsequently, amino groups in the resulting APTS-γFeO beads were converted to carboxylic acid (CARB-γFeO) through the succinic anhydride reaction, as confirmed by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy and dynamic light scattering (DLS) measurements. The size of these beads was measured as 12 nm and their hydrodynamic diameter as 490 nm, using TEM analysis and DLS, respectively. The CARB-γFeO beads were further functionalized by immobilizing rabbit antibodies on their surfaces; the immobilization was confirmed by flow cytometry and ionic strength. The samples were further characterized by Mössbauer spectroscopy and DC magnetization measurements. Studies on magnetic relaxivities showed that magnetic beads present great potential for application in MR imaging.

Fabrication, Microstructure and Colloidal Stability of Humic Acids Loaded Fe3O4/APTES Nanosorbents for Environmental Applications

“…The isoelectric point (IEP) of Fe 3 O 4 NPs (Figure 5) was found to be 6.3, which is in accordance with values in the literature [49]. The IEP corresponds to the pH regime where the net charge on the NPs reaches zero [50]. The reactions of surface ≡Fe-OH sites of magnetite, which can lead to the formation of positive (≡Fe-OH + 2 ) and negative (≡Fe-O − ) surface charges, were observed [48].…”

“…However, it cannot be ignored that the bare magnetite was transformed to maghemite after functionalization in the air atmosphere. Rodriquez et al [50] have reported that the IEP for γ-Fe 2 O 3 NPs is located at pH = 3.22. This IEP is very low, and we suspect the lowering effect of an unidentified trace contaminant like humate, phosphate.…”

Synthesis and Characterization of Maghemite Nanoparticles Functionalized with Poly(Sodium 4-Styrene Sulfonate) Saloplastic and Its Acute Ecotoxicological Impact on the Cladoceran Daphnia magna

“…IR peaks ca. 434, 534, and 619 cm −1 indicate the metal–oxygen bonding found in the tetrahedral sites, where the first peak could correspond to the only deformation of octahedral sites of the γ-Fe 2 O 3 phase [ 33 , 34 , 35 , 36 ]. Bali et al [ 34 ] have identified an IR peak at about 2925 cm −1 and associating it with the stretching vibration of the C-H bond.…”

Hierarchical Structure of Magnetic Nanoparticles -Fe₃O₄- Ferrofluids Revealed by Small Angle X-Ray Scattering

“…2, the scattering pattern at the first region at large-q values shows the characteristic of the interference between the scattering object and the solvent. This region is called the Porod zone, which means that the primary particles' scattering intensity decreases following a power law of I(q) ~ q 4 . In this region, the scattering pattern is started at the high to intermediate q region as S(q) ≈ 1.…”

“…As a fundamental understanding, the importance of the aggregation and the properties of the hierarchical structure of MNPs Fe3O4 becomes a crucial matter that must be explored further due to its effects on magnetic properties and applications. Rodriquez et al [4] and Sulungbudi et al [5] have measured magnetic nanoparticles' structure using dynamic light scattering (DLS) and transmission electron microscopy (TEM). By comparing the size that was measured using DLS and TEM, they pointed out that the particles formed aggregates.…”