Facile fabrication of multi-colors high fluorescent/superparamagnetic nanoparticles

We developed a novel method to prepare multi-colors high fluorescent/superparamagnetic nanoparticles (FMNPs) employing hydrophobic multi-color quantum dots (QDs) and hydrophobic Fe3O4 (MNPs) via ultrasonic emulsification method. This structural procedure was simple, one-off, and timesaving. Different-sizes FMNPs with encoding single/multi-color QDs and MNPs were achieved. Analysis with transmission electron microscopy (TEM) and particle size analyzer demonstrated that the as-prepared samples were spherical, uniform in size distribution; Ultraviolet-visible (UV-vis) absorption spectroscopy and photoluminescence (PL) measurement showed the FMNPs had good optical properties, lacking of fluorescence resonance energy transfer (FRET) inside FMNPs; vibrating sample magnetometer (VSM) indicated that FMNPs were superparamagnetic. These results indicate that the as-prepared FMNPs have potential of serving as a hybrid of QDs and MNPs in bioanalysis communities. (C) 2008 Elsevier Inc. All rights reserved.