title: Tuning Toehold Length and Temperature to Achieve Rapid, Colorimetric Detection of DNA from the Disassembly of DNA-Gold Nanoparticle Aggregates.
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.
authors.affiliation: Department of Chemistry, University of Alberta , Edmonton T6G 2G2, Canada.
authors.forename: Michael K
authors.initials: MK
authors.lastname: Lam
authors.affiliation: Department of Chemistry, University of Alberta , Edmonton T6G 2G2, Canada.
authors.forename: Tendai
authors.initials: T
authors.lastname: Gadzikwa
authors.affiliation: Department of Chemistry, University of Alberta , Edmonton T6G 2G2, Canada.
authors.forename: Trang
authors.initials: T
authors.lastname: Nguyen
authors.affiliation: Department of Chemistry, University of Alberta , Edmonton T6G 2G2, Canada.
authors.forename: Abu
authors.initials: A
authors.lastname: Kausar
authors.affiliation: Department of Chemistry, University of Alberta , Edmonton T6G 2G2, Canada.
authors.forename: B Safeenaz
authors.initials: BS
authors.lastname: Alladin-Mustan
authors.affiliation: Department of Chemistry, University of Alberta , Edmonton T6G 2G2, Canada.
authors.forename: Md Delwar
authors.initials: MD
authors.lastname: Sikder
authors.affiliation: Department of Chemistry, University of Alberta , Edmonton T6G 2G2, Canada.
authors.forename: Julianne M
authors.initials: JM
authors.lastname: Gibbs-Davis
mesh_terms: D004247:DNA / Q000032:analysis*; D006046:Gold / Q000737:chemistry*; D007700:Kinetics; D053768:Metal Nanoparticles / Q000737:chemistry*; D009691:Nucleic Acid Denaturation; D009693:Nucleic Acid Hybridization; D013696:Temperature
chemical_list: D006046:Gold; D004247:DNA