1. Tuning Toehold Length and Temperature to Achieve Rapid, Colorimetric Detection of DNA from the Disassembly of DNA-Gold Nanoparticle Aggregates.
- Author
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Lam MK, Gadzikwa T, Nguyen T, Kausar A, Alladin-Mustan BS, Sikder MD, and Gibbs-Davis JM
- Subjects
- Kinetics, Nucleic Acid Denaturation, Nucleic Acid Hybridization, Temperature, DNA analysis, Gold chemistry, Metal Nanoparticles chemistry
- Abstract
Gold nanoparticles have been widely utilized to achieve colorimetric detection for various diagnostic applications. One of the most frequently used methods for DNA detection involves the aggregation of DNA-modified gold nanoparticles driven by target DNA hybridization. This process, however, is intrinsically slow, limiting its use in rapid diagnostics. Here we take advantage of the reverse process: the disassembly of preformed aggregates triggered by the addition of target DNA via a strand displacement mechanism. A systematic study of the dependence of the disassembly rate on temperature, with and without toeholds, has delivered a system that produces an extremely rapid colorimetric response. Furthermore, using an optimal toehold length of 5 nucleotides, target triggered disassembly is rapid over a wide range of ambient temperatures. Using this overhang system, simple visualization of low picomole amounts of target DNA is possible within 10 min at room temperature.
- Published
- 2016
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