Synthesis and characterization of magnetic-fluorescent composite colloidal nanostructures

In this communication, we report fluorescent and magnetic bifunctional structures in the nanoscale range. The synthesis and characterisation of various colloidal nanostructures as Y₃F_e5-xAl_xO₁₂-TRITC, gamma-Fe₂O₃-Cs₂Mo₆Br₁₄@SiO₂ and Fe₂O₃-QDs will be presented. At the outset, the first synthesis of aluminium substituted YAIG (Y₃Fe_5-xAl_xO₁₂) by the citrate gel process and its surface modification by TRITC through grafting of 3-aminopropyltrimethoxysilane (g-APS) for biology-related labelling will be reported. Secondly, the synthesis of nanoparticles under restricted environments offered by water-in-oil microemulsions provides excellent control over particle size and shape and interparticle spacing. These environments have been used in the synthesis of silica nanoparticles (50 nm) with magnetic nanocrystals core surrounded by optically active nanoclusters. Finally, we will describe the preparation of composite magnetic QD bioconjugable micelles by simultaneous encapsulation of hydrophobic CdSe/ZnS QDs (2-4 nm) and magnetic gamma-Fe₂O₃ nanoparticles (3-4 nm) into micelles of synthetic functional PEG amphiphiles bearing a bioactivable terminal group.