Here, we present the synthesis and characterization of a new nano-composite, CdTe-FeP magnetic quantum dot nanoparticles. These materials, which exhibit a dumbbell shape morphology are further encapsulated with silica to produce a core-shell structure. The magnetic quantum dots, CdTe-FeP, were prepared through a one-pot chemical method based on high temperature precursor decomposition of both materials in trioctyl phosphine oxide (TOPO). The silica shell was formed using a reverse micro-emulsion technique.
To characterize this material, we investigated the effect of the synthesis conditions and CdTe: FeP mole ratios on magnetic and fluorescent properties as measured by TEM, XRD, UV, XPS, fluorescence spectroscopy, and superconducting quantum interference device (SQUID). Results indicate that nano-composites exhibit magnetic and fluorescent properties; however, the magnetism exhibited by FeP appeared to change from ferromagnetic to paramagnetic after conjugation with CdTe. Also, the quantum yield of CdTe decreased after conjugation. These data suggest an interaction between the magnetic and fluorescent features of the individual particles. These core-shell nanocomposites have potential applications in diagnostics, circulating drug-delivery systems, and treating cancer at its earliest stages.