, Volume 4, Issue 10, pp 1230-1235,
Open Access This content is freely available online to anyone, anywhere at any time.
Date: 15 Jul 2009

Synthesis of Starch-Stabilized Ag Nanoparticles and Hg2+ Recognition in Aqueous Media


The starch-stabilized Ag nanoparticles were successfully synthesized via a reduction approach and characterized with SPR UV/Vis spectroscopy, TEM, and HRTEM. By utilizing the redox reaction between Ag nanoparticles and Hg2+, and the resulted decrease in UV/Vis signal, we develop a colorimetric method for detection of Hg2+ ion. A linear relationship stands between the absorbance intensity of the Ag nanoparticles and the concentration of Hg2+ ion over the range from 10 ppb to 1 ppm at the absorption of 390 nm. The detection limit for Hg2+ ions in homogeneous aqueous solutions is estimated to be ~5 ppb. This system shows excellent selectivity for Hg2+ over other metal ions including Na+, K+, Ba2+, Mg2+, Ca2+, Fe3+, and Cd2+. The results shown herein have potential implications in the development of new colorimetric sensors for easy and selective detection and monitoring of mercuric ions in aqueous solutions.