Colorimetric nitrite and nitrate detection with gold nanoparticle probes and kinetic end points.
We report the development of a novel colorimetric nitrite and nitrate ion assay based upon gold nanoparticle probes functionalized with Griess reaction reagents. This assay takes advantage of the distance-dependent plasmonic properties of the gold nanoparticles and the ability of nitrite ion to facilitate the cross coupling of novel nanoparticle probes modified with aniline and naphthalene moieties. The assay works on the concept of a kinetic end point and can be triggered at the EPA limit for this ion in drinking water (highlighted in red, microM). This rapid and simple assay could be useful for on-site water quality monitoring.
Department of Chemistry and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA.
Weston L
WL
Daniel
Min Su
MS
Han
Jae-Seung
JS
Lee
Chad A
CA
Mirkin
D003124:Colorimetry / Q000379:methods*; D006046:Gold; D007700:Kinetics; D053768:Metal Nanoparticles / Q000737:chemistry; D015336:Molecular Probe Techniques; D015335:Molecular Probes / Q000737:chemistry; D009566:Nitrates / Q000032:analysis*; D009573:Nitrites / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
D015335:Molecular Probes; D009566:Nitrates; D009573:Nitrites; D014874:Water Pollutants, Chemical; D006046:Gold