PROCEEDINGS ARTICLE | March 13, 2013
Proc. SPIE. 8595, Colloidal Nanocrystals for Biomedical Applications VIII
KEYWORDS: Nanoparticles, Quantum dots, Magnetism, Zinc, Biomedical optics, Manganese, Magnetic resonance imaging, Transmission electron microscopy, Selenium, Particles
Colloidal quantum dots (QDs) are of interest for a variety of biomedical applications, including bioimaging, drug
targeting, and photodynamic therapy. However, a significant limitation is that highly efficient photoluminescent QDs
available commercially contain cadmium. Recent research has focused on cadmium-free QDs, which are anticipated to
exhibit significantly lower cytotoxicity. Previous work has focused on InP and ZnO as alternative semiconductor
materials for QDs. However, these nanoparticles have been shown to be cytotoxic. Recently, we have synthesized high
quantum efficiency (exceeding 90%), color tunable MnSe/ZnSeS nanoparticles, as potentially attractive QDs for
biomedical applications. Additionally, the manganese imparts magnetic properties on the QDs, which are important for
magnetic field-guided transport, hyperthermia, and potentially magnetic resonance imaging (MRI). The QDs can be
further biofunctionalized via conjugation to a ligand or a biomarker of disease, allowing combination of drug delivery
with visual verification and colocalization due to the color tunability of the QDs.
