Homogeneous detection of nucleic acids based upon the light scattering properties of silver-coated nanoparticle probes

Xiaoyang Xu, Dimitra G. Georganopoulou, Haley D. Hill, Chad A. Mirkin*

*Corresponding author for this work

Research output: Contribution to journalArticle

92 Scopus citations

Abstract

Herein we report the development of a simple, rapid, homogeneous, and sensitive detection system for DNA based on the scattering properties of silver-amplified gold nanoparticle probes. The assay uses DNA-functionalized magnetic particle probes that act as scavengers for target DNA, which can be collected via a magnetic field. Once the DNA targets are isolated from the initial sample, they are sandwiched via hybridization by a second set of probes. The latter probes are 13-nm gold nanoparticles modified with a different target complementary DNA. Excess probes are removed through repetitive washing steps. The gold particles are dispersed in solution by dehybridization, corresponding to an assumed 1:1 ratio with the target DNA. Electroless deposition of silver on the surface of the gold probes results in particle growth, which increases their scattering efficiency with time. The scattering efficiency and the extinction signatures of the particle sizes are monitored as a function of time and correlated with target concentration. The limit of detection for this novel assay was determined to be 10 fM.

Original languageEnglish (US)
Pages (from-to)6650-6654
Number of pages5
JournalAnalytical Chemistry
Volume79
Issue number17
DOIs
StatePublished - Sep 1 2007

ASJC Scopus subject areas

  • Analytical Chemistry

Fingerprint Dive into the research topics of 'Homogeneous detection of nucleic acids based upon the light scattering properties of silver-coated nanoparticle probes'. Together they form a unique fingerprint.

  • Cite this