We have used different wet chemical methods to synthesise magnetic nanoparticles of different compositions, size, shapes and surface chemistries. Here are few examples:  1.Tunable shapes of magnetic nanoparticles: Fe-Pt, Fe-Pd and Fe-Pt-Pd alloysFor biomedical applications, shape-variant NPs have immediate utility in biomedical immuno-electron microscopy which allows differentiation by both size and shape simultaneously. We achieved the controlled syntheses of Fe-Pt, Fe-Pd and Fe-Pt-Pd nanoparticles having different isolated shapes including sphere, cube, octopod-cube, star, rod, bilobe, tetrahedron, or multipod with size of 5-50 nm.  The as-synthesised NPs are homogeneous and no further size selection is needed. The formation of such a wide range of shapes from a single synthetic method allowed obtaining useful information into the growth mechanism of the NPs. 2.Synthesis of magnetic nanoalloys from bimetallic carbonyl clustersMagnetic alloy nanoparticles are of interest due to their enhanced magnetic properties and chemical stability. However, controlling the composition of magnetic alloy nanoparticles can be difficult, when they are produced from two or more precursors. This may be overcome by the use of a single bimetallic precursor. Here we report the synthesis of FeCo3, FeNi4, Fe3Pt3 and Fe4Pt alloy magnetic nanoparticles with average diameters of 7.0 nm, 4.4 nm, 2.6 nm and 3.2 nm, respectively, by the thermal decomposition of bimetallic carbonyl clusters. The chemical composition of the synthesized nanoparticles reflected that of the bimetallic carbonyl cluster used for their synthesis. Changing the reaction conditions, such as ligand concentration, ligand type and reaction temperature had very little effect upon the chemical and physical properties of the synthesized nanoparticles.  3.Facile synthesis of stable water-soluble magnetic CoPt: solid, nanochains/wires and hollow nanoparticlesA novel, facile, template-free synthetic method of water-soluble CoPt NPs by simultaneous reduction of cobalt and platinum salts in water in the presence of polymer and/or peptide ligands. By varying polymer/peptide ligands, their concentrations and cobalt/platinum salt ratio, solid, hollow NPs and nanochains/wires were fabricated. The CoPt hollow nanostructures are superparamagnetic at room temperature, stable in water with pH in the range from 1 to 10 and NaCl concentration up to 2 M.  4.Superparamagnetic Fluorescent Nickel-Enzyme NanobioconjugatesSuperparamagnetic and fluorescent nickel (Ni) nanoparticles directly conjugated to an enzyme, bovine pancreatic a-chymotrypsin (CHT) by chemical reduction in aqueous solution was synthesised and characterised. To confirm the conjugation of Ni NPs to CHT, we carried out FRET studies using a fluorescent probeNPA, known to bind at the enzymatic active site of CHT, as the donor and Ni-NP-bound CHT as the acceptor

Recent developments in the synthesis of magnetic nanoparticles  for biomedical applications

240th National Meeting (2010)

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