Iron oxide magnetic nanoparticles with versatile surface functions based on dopamine anchors

Abstract

The synthesis of multifunctional magnetic nanoparticles (MF-MPs) is one of the most active research areas in advanced materials as their multifunctional surfaces allow conjugation of biological and chemical molecules, thus making it possible to achieve target-specific diagnostic in parallel to therapeutics. We report here a simple strategy to integrate in a one-step reaction several reactive sites onto the particles. The preparation of MF-MPs is based on their simultaneous modification with differently functionalized dopamine derivatives using simple solution chemistry. The formed MF-MPs show comparable magnetic properties to those of naked nanoparticles with almost unaltered particle size of around 25 nm. The different termini, amine, azide and maleimide functions, enable further functionalization of MF-MPs by the grafting-on approach. Michael addition, Cu(i) catalyzed « click » chemistry and amidation reactions are performed on the MF-MPs integrating subsequently 6-(ferrocenyl)-hexanethiol, horseradish peroxidase (HRP) and mannose.

Increasing the Collision Rate of Particle Impact Electroanalysis with Magnetically Guided Pt-Decorated Iron Oxide Nanoparticles

“…50 The ligand removal procedure and subsequent dopamine surface modification do not appear to significantly affect the size distribution of the iron oxide nanocrystals, as the resulting AT-IONPs remain 18 ((2) nm in size and cubic in shape (Figure 1a,b).…”

Convenient synthesis of heterobifunctional poly(ethylene glycol) suitable for the functionalization of iron oxide nanoparticles for biomedical applications

“…Other anchoring moieties such as carboxylates, phosphonates and catechol ligands, in particular dopamine-based derivatives, have been conjugated to nanoparticulate iron oxides 29 to increase long-term colloidal stability in biological medium 30 and to display multifunctional surfaces. 31 Nevertheless, Fe(III)-mediated oxidation of catechol ligands might induce loss of colloidal stability and produce cytotoxic iron-quinone complexes. 32 The suitability of heterobifunctional PEG molecules 6 and 7 for the pegylation of metal oxide NPs was addressed using USPIO NPs.…”

Hydrothermal synthesis of nanostructured hybrids based on iron oxide and branched PEI polymers. Influence of high pressure on structure and morphology

“…Secondly, in the magnetic frozen regime (at the lowest temperature at 2 K), the coercive field is 3500(50) Oe, 3450(50) Oe and 3000(50) Oe for samples P1, P3 and P5, respectively. While such magnetic monodomain nanoparticles can be treated in the frame of the StonereWohlfarth model [34], the anisotropy constant can be directly obtained as the product between the coercive field and the spontaneous magnetization [23,35]. The so obtained anisotropy constants, K, are 30(2) kJ/m 3 , 40(2) kJ/m 3 and 27(2) kJ/m 3 for samples P1, P3 and P5, respectively.…”