College of Physics and Engineering, Qufu Normal University, Qufu City, Shandong Province, 273165, PR China; College of Chemistry, Chemical Engineering and Materials, Jining University, Qufu City, Shandong Province, 273155, PR China.
Huzhou Key Laboratory of Medical and Environmental Applications Technologies, School of Life Sciences, Huzhou University, Huzhou City, Zhejiang Province, 313000, PR China.
Anal Chim Acta. 2022 May 8;1206:339792. doi: 10.1016/j.aca.2022.339792. Epub 2022 Apr 2.
Water-soluble non-conjugated polymer dots (PDs) have been synthesized using hyperbranched polyethyleneimine (PEI) and dihydroxybenzaldehyde (DHB) for the first time via the Schiff base reaction at room temperature. The yielded non-conjugated PDs of PEI-DHB could display the well-defined spheric structure and good water solubility. In contrast to the common PDs otherwise showing blue emission, the PEI-DHB PDs could give out strong green fluorescence in aqueous media. Especially, the fluorescence of the PEI-DHB PDs could be specifically quenched by MnO nanosheets through the inner filter effects and further restored by the thiocholine that could reduce MnO nanosheets into Mn. Herein, thiocholine could be produced in hydrolysis reaction of acetylthiocholine catalyzed by the acetylcholinesterase (AChE), of which the catalytic activity could be irreversibly inhibitted by the introduction of organophosphates. A highly selective fluorimetric method was thereby been developed for the detection of organophosphorus pesticides using dimethyl-dichloro-vinyl phosphate as a model. The linear concentrations ranges from 0.050 to 2.5 μM. Importantly, the non-conjugated PDs probes with strong green fluorescence and high water solubility may promise the extensive applications in the environmental, food, and clinical analysis fields.
首次在室温下通过希夫碱反应，使用超支化聚乙烯亚胺（PEI）和二羟苯甲醛（DHB）合成了水溶性非共轭聚合物点（PDs）。得到的 PEI-DHB 非共轭 PD 可显示出明确的球形结构和良好的水溶性。与通常显示蓝色发射的常见 PD 不同，PEI-DHB PD 在水介质中可发出强绿光。特别是，MnO 纳米片可以通过内滤效应特异性地猝灭 PEI-DHB PD 的荧光，并且通过还原 MnO 纳米片为 Mn 的硫代胆碱进一步恢复其荧光。在此，硫代胆碱可以在乙酰胆碱酯酶（AChE）催化的乙酰硫代胆碱水解反应中产生，其催化活性可通过引入有机磷不可逆地抑制。因此，建立了一种高选择性的荧光检测方法，使用二甲二氯-乙烯基磷酸盐作为模型检测有机磷农药。线性浓度范围为 0.050 至 2.5 μM。重要的是，具有强绿色荧光和高水溶性的非共轭 PD 探针可能有望在环境、食品和临床分析领域得到广泛应用。
