Selective Detection of Sub-hundred Picomolar Mercuric Ion in Aqueous Systems by Visible Spectrophotometry Using Gripe Water Functionalized Gold Nanoparticles

A selective and sensitive spectrophotometric determination of Hg2+ was designed based on gripe water functionalized gold nanoparticles (AuNP). Gripe waterwas employed as both a reducing and a stabilizing agent for the synthesis of gold nanoparticles. The sugar moieties of gripe water were responsible for the reduction of auric ions to Au and the resultant nanoparticles possessing an average particle size of 16nm were highly stable over a period of 1year. The gripe water-functionalized gold nanoparticle system was highly sensitive in detecting Hg2+ ions in aqueous medium, with the limit of detection being as low as 0.05nM. It was also highly selective of mercury even in presence of eleven different commonly associated cations. The efficacy of the nanoparticle sensor system in the analysis of mercury in real-time samples such as bottled, tap, lake and river water has also been evaluated to be good. [GRAPHICS] .