title: A simple and selective colorimetric mercury (II) sensing system based on chitosan stabilized gold nanoparticles and 2,6-pyridinedicarboxylic acid.
abstract: The development of simple and cost-effective methods for the detection and treatment of Hg2+in the environment is an important area of research due to the serious health risk that Hg2+poses to humans. Colorimetric sensing based on the induced aggregation of nanoparticles is of great interest since it offers a low cost, simple, and relatively rapid procedure, making it perfect for on-site analysis. Herein we report the development of a simple colorimetric sensor for the selective detection and estimation of mercury ions in water, based on chitosan stabilized gold nanoparticles (AuNPs) and 2,6-pyridinedicarboxylic acid (PDA). In the presence of Hg2+, PDA induces the aggregation of AuNPs, causing the solution to change colors varying from red to blue, depending on the concentration of Hg2+. The formation of aggregated AuNPs in the presence of Hg2+was confirmed using transmission electron microscopy (TEM) and UV-Vis spectroscopy. The method exhibits linearity in the range of 300nM to 5μM and shows excellent selectivity towards Hg2+among seventeen different metal ions and was successfully applied for the detection of Hg2+in spiked river water samples. The developed technique is simple and superior to the existing techniques in that it allows detection of Hg2+using the naked eye and simple and rapid colorimetric analysis, which eliminates the need for sophisticated instruments and sample preparation methods.
authors.affiliation: Nanostructured Materials Research Laboratory, Department of Materials Science and Engineering, University of Utah, Salt Lake City, UT 84112, United States.
authors.forename: Kun
authors.initials: K
authors.lastname: Tian
authors.affiliation: Nanostructured Materials Research Laboratory, Department of Materials Science and Engineering, University of Utah, Salt Lake City, UT 84112, United States.
authors.forename: Gene
authors.initials: G
authors.lastname: Siegel
authors.affiliation: Nanostructured Materials Research Laboratory, Department of Materials Science and Engineering, University of Utah, Salt Lake City, UT 84112, United States. Electronic address: tiwari@eng.utah.edu.
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Tiwari
mesh_terms: D048271:Chitosan / Q000737:chemistry*; D003124:Colorimetry / Q000379:methods; D006046:Gold / Q000737:chemistry*; D006877:Hydroxamic Acids / Q000737:chemistry*; D008628:Mercury / Q000032:analysis*; D053768:Metal Nanoparticles / Q000737:chemistry*
chemical_list: D006877:Hydroxamic Acids; C024588:2,6-pyridinedicarbohydroxamic acid; D006046:Gold; D048271:Chitosan; D008628:Mercury
keywords: 2,6-pyridinedicarboxylic acid; Colorimetric sensing; Gold nanoparticle; Hg(II) sensing