title: A colorimetric probe to determine Pb(2+) using functionalized silver nanoparticles.
abstract: A simple and sensitive colorimetric method for the determination of Pb(2+) ions in aqueous samples was developed using 1-(2-mercaptoethyl)-1,3,5-triazinane-2,4,6-trione (MTT) functionalized silver nanoparticles (MTT-AgNPs). The Pb(2+) ion acted as the metal center of the coordination complex, which formed N-Pb(2+)-O coordination bonds with the MTT-AgNPs, shortening the interparticle distance, and inducing aggregation of the MTT-AgNPs. This aggregation resulted in a dramatic color change from yellow to dark blue. Using this methodology, the concentration of Pb(2+) ions in environmental samples could be quantitatively detected with the naked eye or by using UV-vis spectrometry. Also, we found that the selectivity and sensitivity of detection were noticeably improved in the pH range of 7-8, at which a more obvious color change was observed. The absorption ratios (A625/A395) of the modified AgNP solution exhibited a linear correlation with Pb(2+) ion concentrations within the linear range of 0.1-0.6 μg mL(-1), and the limits of detection in tap and pond water were 0.02 and 0.06 μg mL(-1), respectively. This cost-effective sensing system allows for the rapid and facile determination of Pb(2+) ions in aqueous samples.
authors.affiliation: Advanced Analysis Center and Green City Technology Institute, Korea Institute of Science and Technology, P.O. Box 131, Cheongryangri, Seoul 130-650, Republic of Korea. leekb@kist.re.kr and Department of Chemistry, Korea University, P.O. Box 145, Anam-ro, Seongbuk-gu, Seoul 136-701, Republic of Korea.
authors.forename: Kwon-Chul
authors.initials: KC
authors.lastname: Noh
authors.affiliation: Advanced Analysis Center and Green City Technology Institute, Korea Institute of Science and Technology, P.O. Box 131, Cheongryangri, Seoul 130-650, Republic of Korea. leekb@kist.re.kr.
authors.forename: Yun-Sik
authors.initials: YS
authors.lastname: Nam
authors.affiliation: Advanced Analysis Center and Green City Technology Institute, Korea Institute of Science and Technology, P.O. Box 131, Cheongryangri, Seoul 130-650, Republic of Korea. leekb@kist.re.kr.
authors.forename: Ho-Jin
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Advanced Analysis Center and Green City Technology Institute, Korea Institute of Science and Technology, P.O. Box 131, Cheongryangri, Seoul 130-650, Republic of Korea. leekb@kist.re.kr.
authors.forename: Kang-Bong
authors.initials: KB
authors.lastname: Lee
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D003124:Colorimetry / Q000295:instrumentation*; D004784:Environmental Monitoring / Q000379:methods*; D007477:Ions / Q000032:analysis; D007854:Lead / Q000032:analysis*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D015394:Molecular Structure; D012834:Silver / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D007477:Ions; D014874:Water Pollutants, Chemical; D007854:Lead; D012834:Silver