Synthesis of bioconjugated gold nanoparticles for targeted imaging of breast cancer cells

With the rising incidence rate of breast cancer worldwide, it is important to develop diagnostic tools that can selectively and sensitively detect the cancer cells at early stages for early intervention. Here, we use bioconjugated gold nanoparticles to detect and image breast cancer cells under dark field microscopy. Gold nanoparticles have localized surface plasmon resonance effect which allows them to scatter light intensely for bioimaging. They also have characteristics such as superior photostability, easy bioconjugation, and optical tunability which are suitable for long term and multiplexed detection. In this research, we prepared 20 nm gold nanoparticles for synthesis of 50 nm particles so that they can be used for dark field imaging of breast cancer cells. Next, we encapsulated the 50 nm gold nanoparticles in PDA before attaching Herceptin antibodies onto the PDA layer. Finally, the bioconjugated gold nanoparticles were used to selectively and specifically detect SKBR-3 breast cancer cells by binding to the HER2 receptors overexpressed on their surface. The modified particles were also allowed to interact with MCF-7 control cells which are HER2 negative. Dark field images showed binding of gold nanoparticles on cell membranes of SKBR-3 cells while little or no particles were distributed near the HER2 negative MCF-7 cells. Therefore, we synthesized gold nanoparticles that can selectively and sensitively detect cancer cells for bioimaging and biosensing by modifying them with specific targeting ligands.Bachelor of Engineering (Chemical and Biomolecular Engineering