Faculty of Engineering and Natural Sciences
NANOMOLECULAR APPLICATIONS OF GOLD: DRUG DELIVERY NANOCARGOS and (BIO)SENSORS
MUSTAFA SELMAN YAVUZ
Research in the field of conducting polymers has been gaining great attention due to their relatively low processing cost, light-weight and flexibility as compared to their inorganic counterparts. However, processability remains as a considerable hurdle in the way of implementing such technology in more applications. A synthetic route towards a processable and insulating precursor polymer was employed. Upon oxidation, the precursor polymers were converted to their respective conducting forms in aqueous or organic media. The conducting polymer-decorated devices were applied as a biosensor for early cancer detection and as a chemical sensor for volatile organic molecules. We have also investigated the tunability of surface plasmon resonance in conjugated polymer functionalized gold nanoparticles. The reversibly tunable surface plasmon band of the gold nanoparticles was achieved by electrochemically switching between reduced and oxidized states of the conjugated polymer networks.
The use of photosensitive caged compounds has drastically enhanced our ability to address the complexity of a biological system because of the capability to generate effectors with remarkable spatial and temporal resolutions. In a typical process, the masking or caging effect is removed from a precursor compound by photolysis (typically with ultraviolet light) to liberate bioactive species. Although this technique has been successfully applied to a variety of biological studies, it still suffers from multi-step synthesis of specific effectors and from the mortal damages to cells, neurons, and other biological samples during the treatment of the ultraviolet light. We demonstrate a novel delivery platform based on the photothermal effect of gold nanocages in the near-infrared (NIR) region that can solve these problems. In principle, this new system can work with many types of effectors without involving any dedicated synthesis, and is well-suited for in vivo studies due to the well-known high transparency of soft tissue in the NIR region.
March 4, 2009, 13:40, G032