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Date: Tuesday, May 10, 2016
Time: 11:00 am
Speaker: Frank van Veggel, University of Victoria
Title: On the Optical and Magnetic Properties of Ln3+ Based Nanoparticles for Bio-Imaging
Location: 67-3111 Chemla Room


Abstract:

One of our main research thrusts in the field of colloidal nanomaterials and their applications is based on the trivalent lanthanide ions, which have unique optical and magnetic properties. We cover the range from synthesis and characterisation to (in vivo) applications, with a recent focus on MRI (Magnetic Resonance Imaging) for cancer diagnostics. The colloidal stability is typically obtained by a “soft” layer of organic molecules. To this purpose, we have developed synthesis techniques to make core-shell architectures which allows the optical and magnetic properties to be optimized separately. Additionally, we do surface modifications by organic chemistry to impart compatibility with biological media and to impart binding specificity (e.g. through antibodies).

The synthesis and basic characterisation of the nanoparticles will only briefly be discussed, but the core-shell synthesis will be discussed in some detail. Some emphasis will be on the challenges to prove the actual formation of core-shell structures and the Ln3+ dopant distribution. The main focus of the talk is on their surface modification and use as optical and magnetic probes for bioimaging. I will also make some critical remarks about the brightness and (absolute) quantum yields of upconversion nanoparticles as well as there usefulness for “deep-tissue“ imaging. Some recent in vivo MRI studies will be included showing their potential as MRI contrast agent at high magnetic fields in brain, breast and prostate cancer.