Water-soluble nonconjugated fluorescent polymer nanoparticles (NFPNs) were prepared from branched polyethylenimine (PEI) and citric acid through an amide condensation reaction in the aqueous phase. The NFPNs were characterized using a transmission electron microscope, Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectra (XPS). The NFPN fluorescence (with excitation/emission peaks at 360/450 nm) was quenched by 2,4,6-trinitrophenol (TNP) at trace concentrations through the inner filter effect and the formation of self-assembled non-fluorescent Meisenheimer complexes of TNP on the NFPN surfaces through acid-base interactions. The complexes effectively enriched TNP from the bulk solution on the NFPN surfaces through acid-base interactions, and the strong overlap between NFPN excitation and TNP absorption peaks contributed to NFPNs having good sensitivity and selectivity for TNP. The method was selective for TNP and was not sensitive to other interfering species. The calibration plot of log(F0/F) versus TNP concentration shows a linear relationship (R2 = 0.999) for TNP concentration in the range of 0.5-150 μM. The detection limit for TNP was 0.7 μM. The assay was successfully used to determine TNP in spiked lake water samples, and the recoveries were 96.6-102.7%.

中文翻译：

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非共轭荧光聚合物纳米粒子的制备，用作检测2,4,6-三硝基苯酚的荧光探针。

通过支化聚乙烯亚胺（PEI）和柠檬酸通过水相中的酰胺缩合反应制备水溶性非共轭荧光聚合物纳米颗粒（NFPN）。使用透射电子显微镜，傅立叶变换红外（FTIR）光谱和X射线光电子能谱（XPS）对NFPN进行表征。NFPN荧光（在360/450 nm处具有激发/发射峰）通过内部过滤效应和形成TNP自组装非荧光Meisenheimer配合物的痕量浓度的2,4,6-三硝基苯酚（TNP）淬灭通过酸碱相互作用在NFPN表面上形成。配合物通过酸碱相互作用有效地从NFPN表面的本体溶液中富集了TNP，NFPN激发和TNP吸收峰之间的强烈重叠有助于NFPN对TNP具有良好的敏感性和选择性。该方法对TNP具有选择性，对其他干扰物种不敏感。log（F0 / F）对TNP浓度的校准曲线显示了TNP浓度在0.5-150μM范围内的线性关系（R2 = 0.999）。TNP的检出限为0.7μM。该方法已成功用于测定加标的湖水样品中的TNP，回收率为96.6-102.7％。7微米 该方法已成功用于测定加标的湖水样品中的TNP，回收率为96.6-102.7％。7微米 该方法已成功用于测定加标的湖水样品中的TNP，回收率为96.6-102.7％。