Abstract Title

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

Additional Funding Sources

This project is supported by the American Chemical Society Project SEED Program.

Abstract

Gold nanoparticles (AuNP) change color based on the oscillation of free electrons known as surface plasmon resonance. AuNPs are good optical markers due to their high surface to volume ratio and their large extinction coefficients. Unlike other metal nanoparticles such as silver, the color change caused by aggregation of AuNPs is easier to observe, allowing the fabrication of a colorimetric sensor to be efficient and inexpensive. Using an autocatalytic DNA network and AuNPs, the colorimetric sensing signal can be significantly amplified to create a sensitive 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 DNA and biotin-streptavidin interaction. Sensitivity of this network was tested in the presence of DNA fuel strands and varying amounts of catalyst strands. In addition, the network operation wais optimized based on the design of DNA reaction networks and active DNA strand density on the nanoparticles. The resulting nanoscopic assemblies will be used for applications such as biological imaging, chemical sensing, and optoelectronic devices.

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

Gold nanoparticles (AuNP) change color based on the oscillation of free electrons known as surface plasmon resonance. AuNPs are good optical markers due to their high surface to volume ratio and their large extinction coefficients. Unlike other metal nanoparticles such as silver, the color change caused by aggregation of AuNPs is easier to observe, allowing the fabrication of a colorimetric sensor to be efficient and inexpensive. Using an autocatalytic DNA network and AuNPs, the colorimetric sensing signal can be significantly amplified to create a sensitive 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 DNA and biotin-streptavidin interaction. Sensitivity of this network was tested in the presence of DNA fuel strands and varying amounts of catalyst strands. In addition, the network operation wais optimized based on the design of DNA reaction networks and active DNA strand density on the nanoparticles. The resulting nanoscopic assemblies will be used for applications such as biological imaging, chemical sensing, and optoelectronic devices.