Authors: S. Santra, H. Yang, S.K. Sabui, P. Sharma, P.H. Holloway, G.A. Walter, B.M. Moudgil and E. Scott
Affilation: University of Central Florida, United States
Pages: 263 - 266
Keywords: multimodal, quantum dots, MRI
Fluorescent quantum dots (Qdots) have demonstrated their potential in diagnostic bioimaging applications in vitro. For in vivo bioimaging applications, however, the embodiment of additional properties such as paramagnetism onto the same fluorescent probes is highly desirable. These multimodal probes would benefit in vivo disease diagnosis and surgical guidance based on their ability to be detected in multiple modes (i.e. optically and magnetically). This talk will focus on a single-step multimodal Qdot synthesis and surface modification technique that can be used for making various engineered multimodal nanoparticles including Qdots. In short, multimodal-imaging quantum dots with an inner crystal diameter of ~ 3 nm and a 4–7 nm thick silica layer have been developed. Paramagnetic GdIII functionalization via a metalchelating silane coupling agent (TSPETE) to the yellow fluorescent, silica-coated CdS:Mn/ZnS core/shell quantum dots resulted in multimodal nanoparticles that can be imaged optically and by MRI. An average of 107 GdIII ions per quantum dot was attached. Gd–Qdots possessed large proton relaxivities of 20.5 mM–1s–1 (R1) and 151 mM–1s–1 (R2) and are a promising MRI contrast agent that could be used for biological imaging of live cells.