Determination of Mercury(II) in Aquatic Plants Using Quinoline-Thiourea Conjugates as a Fluorescent Probe

Abstract

In this study, a quinoline-thiourea conjugate (1-phenyl-3-(quinoline-8-yl) thiourea, PQT) was synthesized and used as a fluorescence sensor to detect mercury ion. The observation is coincident with the well-documented phenomenon that a thiocarbonyl-containing group on a fluorochrome quenches the fluorescence due to the heavy atom effect of the S atom. The large fluorescence enhancement of PQT in the buffered MeCN-water mixture (1/1 v/v; HEPES 100 mM; pH 8.0) was caused by the Hg 2+ induced transformation of the thiourea function into a urea group. As such, protic solvents can be ascribed to hydrogen bond formation on the carbonyl oxygen to reduce the internal conversion rate. The fluorescence intensity of PQT was enhanced quantitatively with an increase in the concentration of mercury ion. The limit of detection of Hg 2+ was 7.5 nM. The coexistence of other metal ions with mercury had no obvious influence on the detection of mercury. A quinolone-thiourea conjugate was used as a fluorescent probe to detect Hg 2+ in aquatic plants and the experimental results were satisfactory.

Fabrication of Water-soluble Fluorescent Polymeric Micelles for Selective Detection of Hg2+ in Blood Serum

“…[1][2][3][4][5] Mercury ion (Hg 2+ ) posed a tremendous menace owing to its bioaccumulation, such as permanent damage and slow accumulation in the central nervous and endocrine systems. 6 Moreover, it can easily give rise to a wide variety of diseases, including prenatal brain damage, serious cognitive problems, motion disorders and Minamata disease.…”