Gold Nanoclusters for Biomedical Imaging

Aaron Gerard Issac Poster: Gold Nanoclusters for Biomedical Imaging

Abstract:

Biomedical imaging allow for targeting of tumors in the body with gold nanoclusters. Typical studies with gold show that after increased amounts of time in the body toxicity issues can develop. In order to prevent this, the focus of this is synthesizing biodegradable gold nanoclusters for photoacoustic imaging. The gold nanoclusters are synthesized from primary gold nanoparticles that are small enough to allow for efficient renal clearance. Furthermore, the gold nanoclusters must be under 50nm to prevent being taken up by cells in the body. The gold nanoclusters are analyzed for a high absorbance in the near IR region, where the body tissue has a low absorbance. This contrast allows for better imaging of targeted tumors. The gold nanoclusters are synthesized using the following ligands: Glutathione (GSH), Cysteine (Cys), and Taz. The use of these ligands allows for close spacing between the nanoparticles. Furthermore, the stabilization provided by these ligands prevents sintering of the particles, and allows them to disassociate back into primary particles. The growth of the nanoclusters occurs by self-assembly of the nanoparticles. By decreasing the electrostatic interactions between particles through changing the pH, variations in the surface charge occur. This leads to nanoparticles having an equilibrium distance from each other, and prevents flocculation of particles. By allowing for tuned self-assembly the nanoclusters are more uniform in size, and more monodisperse. This allows for better reproducibility of the clusters in terms of both a high absorbance, and clusters under 50nm.