title: A simple and pH-independent and ultrasensitive fluorescent probe for the rapid detection of Hg2+.
abstract: Development of fluorescent probes for Hg(2+) has become a hot topic in modern chemical research due to its high toxicity. In this paper, we for the first time report the synthesis and application of a thioether spirocyclic rhodamine B derivative (TR) as an efficient fluorescent probe for Hg(2+). TR was synthesized using a simple procedure under mild condition. By employing a thioether spirocycle instead of classic spirolactam as recognition unit, our proposed probe TR is acidity-insensitive, and exhibits a pH-independent and ultrasensitive response to Hg(2+). The probe works well within a wide pH range from 3.5 to 11.5, and exhibits a 350-fold fluorescence enhancement upon 0.5 equiv of Hg(2+) triggered, with a detection limit of 2.5 nM estimated for Hg(2+). In virtue of the strong thiophilic characteristic of Hg(2+), the response of the probe to Hg(2+) is instantaneous and highly selective, which make it favorable for cellular Hg(2+) imaging applications. It has been preliminarily used for highly sensitive monitoring of Hg(2+) level in living cells with satisfying resolution, demonstrating its value of the practical applications in biological systems.
authors.affiliation: Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Changsha 410082, China.
authors.forename: Ai-Li
authors.initials: AL
authors.lastname: Luo
authors.forename: Yi-Jun
authors.initials: YJ
authors.lastname: Gong
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yuan
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Cui-Cui
authors.initials: CC
authors.lastname: Zhang
authors.forename: Xiao-Bing
authors.initials: XB
authors.lastname: Zhang
authors.forename: Weihong
authors.initials: W
authors.lastname: Tan
mesh_terms: D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D057230:Limit of Detection; D008628:Mercury / Q000032:analysis*; D012235:Rhodamines / Q000138:chemical synthesis* / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013997:Time Factors
chemical_list: D005456:Fluorescent Dyes; D012235:Rhodamines; D013141:Spiro Compounds; D008628:Mercury
keywords: Fluorescent probe; Thioether spirocyclic rhodamine B; Ultrasensitive; pH-independent