title: An efficient rhodamine thiospirolactam-based fluorescent probe for detection of Hg2+ in aqueous samples.
abstract: This paper described the optimized design, synthesis and application of a novel rhodamine thiospirolactam derivative as an 'off-on' fluorescent probe for the detection of Hg(2+) in aqueous samples. The 'off-on' fluorescence and color signal change of the probe is based on an Hg(2+)-triggered domino reaction which brings on the opened-ring form of the rhodamine spirolactam to regain the conjugated system of the rhodamine skeleton. In the well designed probe, the thiospirolactam serves as both Hg(2+) binding unit and electron-defect carbon centre, a phenolic hydroxyl with very strong nucleophilicity after deprotonation is chosen as the attacking unit, and a benzene ring is introduced on the linker to afford steric effects, which benefits an efficient nucleophilic reaction, with a high sensitivity towards Hg(2+). It exhibits a stable response for Hg(2+) from 1.0 × 10(-8) to 1.0 × 10(-6) M, with a detection limit of 3.0 × 10(-9) M. The response of the probe to Hg(2+) is highly selective and pH-insensitive, with a fast response time. All these unique features make it particularly favorable for cellular Hg(2+) imaging applications. It has been preliminarily used for highly sensitive monitoring of Hg(2+) levels in living cells with satisfying resolution.
authors.affiliation: State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, PR China.
authors.forename: Yi-Jun
authors.initials: YJ
authors.lastname: Gong
authors.forename: Xiao-Bing
authors.initials: XB
authors.lastname: Zhang
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Chen
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yuan
authors.forename: Zhen
authors.initials: Z
authors.lastname: Jin
authors.forename: Lei
authors.initials: L
authors.lastname: Mei
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Weihong
authors.initials: W
authors.lastname: Tan
authors.forename: Guo-Li
authors.initials: GL
authors.lastname: Shen
authors.forename: Ru-Qin
authors.initials: RQ
authors.lastname: Yu
mesh_terms: D045744:Cell Line, Tumor; D003124:Colorimetry / Q000379:methods*; D005453:Fluorescence; D005456:Fluorescent Dyes; D006367:HeLa Cells; D006801:Humans; D057230:Limit of Detection; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D012235:Rhodamines / Q000737:chemistry; D014867:Water / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D012235:Rhodamines; D014867:Water; D008628:Mercury