title: Chip-based scanometric detection of mercuric ion using DNA-functionalized gold nanoparticles.
abstract: We have developed a chip-based scanometric method for the detection of mercuric ion (Hg (2+)). This method takes advantage of the cooperative binding and catalytic properties of DNA-functionalized gold nanoparticles and the selective binding of a thymine-thymine mismatch for Hg (2+). The limit of detection of this assay in buffer and environmentally relevant samples (lake water) is 10 nM (2 ppb) Hg (2+), which is the U.S. Environmental Protection Agency (EPA) limit of [Hg (2+)] for drinkable water and 1 order of magnitude lower than previous colorimetric assays. This assay is capable of discriminating Hg (2+) from 15 other environmentally relevant metal ions. The method is attractive for potential point-of-use applications due to its high throughput, convenient readout, and portability.
authors.affiliation: Department of Chemistry and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA.
authors.forename: Jae-Seung
authors.initials: JS
authors.lastname: Lee
authors.forename: Chad A
authors.initials: CA
authors.lastname: Mirkin
mesh_terms: D004247:DNA / Q000737:chemistry* / Q000235:genetics; D006046:Gold / Q000737:chemistry*; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D046208:Microchip Analytical Procedures / Q000379:methods*; D015203:Reproducibility of Results; D014481:United States; D014484:United States Environmental Protection Agency; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D014874:Water Pollutants, Chemical; D014867:Water; D006046:Gold; D004247:DNA; D008628:Mercury