ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
A rhodamine-based Hg2+-selective fluorescent probe in aqueous solution
Minglei Zhao, Xiao-Feng Yang, Shenfeng He, and Liping Wang
Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Institute of Analytical Science,
Department of Chemistry, Northwest University, Xi’an, 710069, China
Received: 13 June 2008 Revised: 16 September 2008 Accepted: 29 September 2008
Abstract: A new rhodamine-based Hg2+-selective fluorescent probe (I) was designed and synthesized. Compound I displays excellent selective and sensitive response to Hg2+ over other transition metal ions in neutral aqueous solutions. I itself is a colorless, nonfluorescent compound. Upon addition of Hg2+ to its solution, the thiosemicarbazide moiety of I undergoes an irreversible desulfurization reaction to form the corresponding 1,3,4-oxadiazole (II), a colorful and fluorescent product, causing instantaneous development of visible color and strong fluorescence emission.
Based on this mechanism, a fluorogenic probe for Hg2+ was developed. The fluorescence increases linearly with the Hg2+ concentration up to 0.8 μmol L−1 with the detection limit of 9.4 nmol L− (3σ).
Keywords: mercury ion - probe - rhodamine B - fluorimetry
Full paper is available at www.springerlink.com.
Chemical Papers 63 (3) 261–267 (2009)