Rapid Colorimetric Detection of DNA via Disassembly of Gold Nanoparticles-Polymer Microbeads

Gold nanoparticles (AuNP) change color based on the oscillation of free electrons also known as surface plasmon resonance. AuNPs are good optical markers due to their high surface to volume ratio and their unique visual properties. As opposed to other metal nanoparticles such as silver, color change caused by aggregation of AuNPs are easier to observe, allowing fabrication of a colorimetric sensor to be quick and inexpensive. Using an autocatalytic DNA network and gold nanoparticles, colorimetric sensing signal can be significantly amplified to create a precise DNA sensor. In order to prepare the AuNP disassembly-based colorimetric sensor, thiolated DNA was attached to AuNPs. After the functionalization, the DNA AuNPs were then assembled onto polymer beads by the hybridization of the DNA.The polymer beads are used as a template to attach the gold and DNA. Sensitivity of this network will be tested and optimized based on the design of DNA reaction networks, size of gold nanoparticles, and nanoparticle density on polymer bead surfaces