RESUMO
The highly selective and sensitive fluorescence "light-up" probe, 5'-(dimethylamino)-2'-formyl-N-hydroxy-[1,1'-biphenyl]-2-carboxamide(PTS), has been fabricated for the nerve-agent mimic diethyl chlorophosphate (DCP). The probe is designed by combining two novel strategies of "covalent assembly" and Lossen rearrangement. Formation of a phosphoryl intermediate from DCP and a hydroxamic acid group in PTS yields an isocyanate that quickly undergoes Lossen rearrangement to produce an aniline that condenses intramolecularly to a fluorescent phenanthridine system. PTS shows superior properties to probe DCP, such as rapid response (within 100 s), low detection limit (10.4 nM), specificity, and excellent linearity (R2 = 0.9993) in the range from 2 to 16 µM. More importantly, its application of detecting DCP vapor has also been achieved with satisfying results.
Assuntos
Compostos de Bifenilo/química , Substâncias para a Guerra Química/análise , Corantes Fluorescentes/química , Compostos Organofosforados/análise , Espectrometria de Fluorescência/métodos , Compostos de Anilina/química , Humanos , Isocianatos/química , Cinética , Limite de Detecção , Mimetismo Molecular , Organofosfatos/análise , Fenantridinas/química , Sarina/análise , Soman/análiseRESUMO
A highly selective fluorescent probe (SiROPS) based on Si-rhodamine (SiR) towards F- was investigated. SiROPS can realize the NIR detection of F- because of the long fluorescent wavelength (λexâ¯=â¯650â¯nm, λemâ¯=â¯669â¯nm). The near-IR optical and the ratiometric fluorescence type signaling were realized by employing fluoride-selective cleavage of the latent thiophosphinated probe in mixed aqueous media. The cleavage of F- to the ortho positions of dimethylphosphinothionyl group in the meso aryl involves the suppression of internal rotation upon phosphorylation of a reactive phenolate and the activating rotation of o-OH, which resulting in a large fluorescence "Turn-Off" response. The detection limit of the probe to F- was 48â¯nM in the dynamic range of 0.5⯵M-20⯵M. In addition, the proposed probe has been used to detect F- in water samples and toothpaste samples with satisfying results.
Assuntos
Corantes Fluorescentes/química , Fluoretos/análise , Compostos de Organossilício/química , Rodaminas/química , Corantes Fluorescentes/síntese química , Raios Infravermelhos , Íons/análise , Estrutura Molecular , Compostos de Organossilício/síntese químicaRESUMO
Based on the fluorophore of 2-(2'-hydroxyphenyl)benzothiazole (HBT) with aggregation-induced emission (AIE) properties, a highly selective and sensitive fluorescent probe PBT towards F- was investigated. "Turn-On" fluorescence type signaling was realized by employing fluoride-selective cleavage of the latent thiophosphinated probe in mixed aqueous media. The probe is designed in such a way that the excited state intramolecular proton transfer (ESIPT) of the HBT moiety becomes blocked. The chemodosimetric approach of F- to the probe results in the recovery of the ESIPT by removal of a free AIE-active HBT moiety through a subsequent hydrolysis process. The F- detection limit of the probe was 3.8 nM in the dynamic range of 0.5 µM to 10 µM. In addition, the proposed probe has been used to detect F- in water samples and toothpaste samples with satisfying results.