Colorimetric Detection of DNA via Catalytic Disassembly of Gold Nanoparticles

Abstract

Gold nanoparticles exhibit colorimetric properties due to plasmonic coupling that can be utilized for DNA sensing. We are attempting to incorporate an autocatalytic DNA reaction mechanism to induce the separation of gold nanoparticle aggregates. The catalytic disassembly nature of the network allows for separation of multiple aggregated particles, which enhances target DNA detection sensitivity and yields faster sensing than an aggregation-based colorimetric detection system. The network includes two particles functionalized with complementary strands of DNA, the target strand of interest, and a fuel strand to complete the disassembly. To induce the aggregation, the functionalized particles were combined and vortexed. Different concentrations of the target and fuel strands were added to the aggregates and their absorbance was monitored over time. Results have shown a clear difference in absorbance of solutions with target and fuel compared to those without, confirming that the particles are separating to an extent. In order to achieve better performance of the disassembly, the effects of ionic strength and stoichiometry of particles are being investigated