title: A two-color-change, nanoparticle-based method for DNA detection.
abstract: Herein, we describe the detailed synthesis of Ag/Au core-shell nanoparticles, the surface-functionalization of these particles with thiolated oligonucleotides, and their subsequent use as probes for DNA detection. The Ag/Au core-shell nanoparticles retain the optical properties of the silver core and are easily functionalized with thiolated oligonucleotides due to the presence of the gold shell. As such, the Ag/Au core-shell nanoparticles have optical properties different from their pure gold counterparts and provide another "color" option for target DNA-directed colorimetric detection. Size-matched Ag/Au core-shell and pure gold nanoparticles perform nearly identically in DNA detection and melting experiments, but with distinct optical signatures. Based on this observation, we report the development of a two-color-change method for the detection and simultaneous validation of single-nucleotide polymorphisms in a DNA target using Ag/Au core-shell and pure gold nanoparticle probes.
authors.affiliation: Department of Chemistry and Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA.
authors.forename: Y Charles
authors.initials: YC
authors.lastname: Cao
authors.forename: Rongchao
authors.initials: R
authors.lastname: Jin
authors.forename: C Shad
authors.initials: CS
authors.lastname: Thaxton
authors.forename: Chad A
authors.initials: CA
authors.lastname: Mirkin