Colorimetric Sensing of DNA via Catalytic Release of Gold Nanoparticles

Gold nanoparticles immobilized on a polymer microbead template via a catalytic DNA network can be functionally used as a colorimetric DNA sensor. Previous sensors have been designed that exploit the colorimetric properties of gold nanoparticles when plasmonically coupled through nanoparticle aggregation. The colorimetric sensing capabilities of gold nanoparticles can also be exploited in reverse first through forming nanoparticle aggregates that are then disassembled through a catalytic DNA network reaction in the presence of the DNA target. The gold nanoparticles are released from the aggregates and the free nanoparticles in solution can then be detected without need of any instrumentation. The early data collected shows that the gold nanoparticle integrated DNA network is responsive to the DNA target. Target concentrations as low as 1 nM were able to be detected. Further optimization is required to increase the sensitivity of the sensor.