CdSe/ZnS Quantum Dots Loaded Solid Lipid Nanoparticles: Novel Luminescent Nanocomposite Particles

Highly luminescent lipophilic CdSe/ZnS core-shell QDs with an emission maximum at 556 nm were synthesized. These QDs were successfully encapsulated into solid lipid nanoparticles (SLNs) using the thin-layer ultrasonication technique. Transmission electron microscopy (TEM), photon correlation spectroscopy (PCS), and zeta potential measurement were employed to characterize the QDs-loaded SLNs for morphology, particle size with polydispersity index (PI), and zeta potential. The nanocomposite particles obtained appeared in a shape of spherical or near spherical with the average size of 92.3 nm, PI of 0.235 and zeta potential of -28.74 mV. Each nanocomposite particle contains tens of QDs observed by TEM. Fluorescence measurements show that the encapsulated QDs maintain their high luminescence and narrow/symmetric emission spectra. The experiment result indicates that the nanocomposite particles are stable and slow to photobleach. These luminescent nanocomposite particles have good potentials in biological imaging applications.