SYNTHESIS AND CHARACTERIZATION OF DENDRITIC MOLECULE-COATED MAGNETIC MAGHEMITE (-Fe2O3) NANOPARTICLES

JULIETA I. PAEZ; ARIEL CAPPELLETTI; ANA B. BARUZZI; VERONICA BRUNETTI; MIRIAM C. STRUMIA

Rouen, Francia

Congreso; POLYCHAR17- World Forum on Advanced Materials; 2009

Nowadays, there is much interest among the academic and industrial scientific community in coated and noncoated magnetic nanoparticles [1]. These nanoparticles, because of their high surface area and unique magnetic properties, have a broad range of potential uses in biomedical applications (e.g., drug delivery [2-3] and biosensors [4],) as well as nonbiomedical applications (e.g., for removal of metal ions [5]). For many of the aforementioned applications, the surface modification of iron oxide nanoparticles has a large influence on their stability and durability in different environments. In addition, dendritic structures are precise quantized, three-dimensional nanostructures that have proved to be useful for functionalization of metallic surfaces due to their monodisperse nature that provides precisely controlled size, shape and functionality [6]. In this work, a synthetic pathway was developed to obtain dendritic molecule-coated magnetic nanoparticles. Figure 1 shows the synthetic strategy used. Briefly, maghemite magnetic iron oxide (g-Fe2O3) nanoparticles NPs were modified with 3-(aminopropyl)trimethoxysilane (APS) as silane coupling agent [7].  Afterwards, dendritic molecule (D NO2) were covalently attached to the modified NPs, achieving nitro-functionalized magnetic nanoparticles. Infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and transmission electronic microscopy (TEM) were used to characterize the derivatised surface.               Figure 1. Synthetic pathway used in order to obtain D NO2-coated magnetic nanoparticles. Subsequently, immobilization of the dendritic molecule-coated NPs onto carbon surfaces (GC and HOPG) was investigated. Attachment of the dendron was followed through the observation of the electrochemical signal of reporting groups such as the nitro group, as was previously reported [8]. _________________ References   [1] Boguslavsky, Y.; Margel, S. J. Colloid Interf. Sci. 2008, 317, 101-114. 2 Gomez-Lopera, S.A; Plaza R.C; Delgado, A.V. J. Colloid Interf. Sci. 2001, 240(1), 40-47. 3 Arruebo, M.; Fernández-Pacheco, R.; Ibarra, M.R.; Santamaría, J. Nanotoday, 2007, 2 (3), 22-32. 4 Lai, G-S.; Zhang, H-L.; Han, D-Y. Sensors Actuat B-Chem, 2008, 129, 497-503. 5 Takafuji, M.; Ide, S.; Ihara, H.; Xu, Z. Chem. Mater., 2004, 16, 1977-1983. 6 Tomalia, D. A. Materials Today, 2003, 6, 72. 7 García, I.; Zafeiropoulos, N-E.; Janke, A.; Tercjak, A.; Eceiza, A.; Stamm, M.; Mondragón, I. J. Polym. Sci: Part A: Polym. Chem. 2006, 370, 121. 8 Paez, J.I.; Froimowicz, P.; Baruzzi, A.M.; Strumia. M.C.; Brunetti, V. Electrochem. Commun., 2008, 10, (4),  541-545.