Recyclable fluorimetric and colorimetric mercury-specific sensor using porphyrin-functionalized Au@SiO2 core/shell nanoparticlesElectronic supplementary information (ESI) available: Measurement data. See DOI: 10.1039/c0an00137f

A fluorimetric/colorimetric mercury sensor based on Au@SiO 2 core/shell nanoparticles has been developed and demonstrated. The porphyrin derivative ( 2 ) was attached to Au@SiO 2 core/shell nanoparticles by covalent bonds and showed a red color and strong fluorescent properties. In the absence of sp...

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Bibliographic Details
Main Authors Cho, Youngje, Lee, Shim Sung, Jung, Jong Hwa
Format Journal Article
LanguageEnglish
Published 21.06.2010
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Summary:A fluorimetric/colorimetric mercury sensor based on Au@SiO 2 core/shell nanoparticles has been developed and demonstrated. The porphyrin derivative ( 2 ) was attached to Au@SiO 2 core/shell nanoparticles by covalent bonds and showed a red color and strong fluorescent properties. In the absence of specific metal ions, the porphyrin-functionalized Au@SiO 2 nanoparticles ( 1 ) exhibited strong fluorescence emission and were red in color. The addition of Hg 2+ ion to 1 resulted in a color change from red to green within 10 s and a weak display of fluorescence. Conversely, no significant changes in fluorescence emission or color were observed in the parallel experiments with Li + , Na + , Ca 2+ , Cu 2+ , Cd 2+ , Co 2+ , Mn 2+ , Cd 2+ , Ag + and Pb 2+ . Regarding the reversibility of 1 , the fluorescence and color of 1 in the presence of Hg 2+ ion were found to be almost reversible when 1 was treated with EDTA solution. Furthermore, a study of the effect of pH on 1 with bound Hg 2+ ion indicated that the fluorescence intensity and color change of 1 was almost constant between pH 4 and 10. This sensor has excellent selectivity and sensitivity over other metal ions and has detection limits below the maximum contamination level of 1.2 ppb for Hg 2+ ion in drinking water, as defined by the U. S. Environmental Protection Agency (EPA). The results obtained not only allow a practical sensing application for the Hg 2+ ion but also serve as a guide for the design of fluorimetric/colorimetric sensors for other targets. Porphyrin derivative immobilized Au@SiO 2 core/shell nanoparticle ( 1 ) recognized and separated Hg 2+ with a high degree of selectivity among heavy metal ions in aqueous solution.
Bibliography:10.1039/c0an00137f
Electronic supplementary information (ESI) available: Measurement data. See DOI
ISSN:0003-2654
1364-5528
DOI:10.1039/c0an00137f