Enhancing the Sensitivity for DNA Detection Using the Gold Nanoparticle System at Lower Concentrations via Controlling Ionic Strength

Gold nanoparticles are widely adopted in a variety of applications such as biomarkers in the diagnostics of diseases and infectious agents, catalysts in chemical reactions, and photodynamic therapy agents for cancer treatment. They can also be used as colorimetric visual markers for the detection DNA. The goal of this research is to study how gold nanoparticle aggregation changes with different salt concentrations. Our hypothesis is that destabilization of gold nanoparticles by raising the concentration of the salt makes it more sensitive toward the target DNA. The procedure requires chemical functionalization of gold nanoparticles with DNA, which enables hybridization with the target DNA and color changes. We will measure the changes in their optical properties as a function of target DNA concentration and ionic strength to identify optimal conditions that maximizes the sensitivity.