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采用一步聚合的方法,制备了以疏水的聚甲基丙烯酸甲酯(PMMA)为核、亲水性的聚电解质支化聚乙烯亚胺(PEI)为壳的纳米粒子分散液.将供体荧光团4-胺基-7-硝基-N-辛基苯并[1,2,5]噁二唑(NBD)以包埋的方式在聚合过程中直接引入PMMA核内部,而受体荧光团罗丹明衍生物SRHB通过吸附作用进入PEI-PMMA核壳界面,构成了含有两种不同荧光分子且可对Hg2+进行荧光比率检测的传感器.考察了含荧光分子的聚合物粒子光谱学性质,证明两种荧光分子均被引入了聚合物粒子体系.在汞离子的荧光检测试验中,加入Hg2+后,体系中的NBD荧光强度下降,而罗丹明的特征发射峰在579 nm处出现,并随着Hg2+浓度的增加,受体/供体的荧光强度比值呈现增长趋势.研究还发现,聚合物粒子基荧光探针对于Hg2+具有较好的选择性,且最佳使用范围是体系pH值在5～8之间,其检测Hg2+的最低浓度可达到1μmol/L.
A one-step polymerization method was used to prepare a nanoparticle dispersion with hydrophilic poly (methylmethacrylate) (PMMA) as core and polyelectrolyte-branched polyethyleneimine (PEI) as shell. The 4-amino-7-nitro-N-octylbenzo [1,2,5] oxadiazole (NBD) is introduced directly into the interior of the PMMA core during the polymerization in an embedded manner, while the acceptor fluorophore The rhodamine derivative SRHB enters the core-shell interface of PEI-PMMA by adsorption and constitutes a sensor containing two different fluorescent molecules and can detect the fluorescence ratio of Hg2 +. The spectral properties of polymer particles containing fluorescent molecules were investigated, Fluorescence molecules were introduced into the polymer particle system.In the mercury ion fluorescence detection test, the addition of Hg2 +, the NBD fluorescence intensity decreased, and the characteristic peak of rhodamine appeared at 579 nm, and with the Hg2 + The fluorescence intensity ratio of acceptor / donor showed an increasing tendency.The study also found that the polymer particle-based fluorescent probe has a good selectivity for Hg2 +, and the best range of use is the system pH value of 5 to 8 Between the detection of the lowest concentration of Hg2 + up to 1μmol / L.