Polydimethysiloxane Modified Silica Nanochannel Membrane for Hydrophobicity-Based Molecular Filtration and Detection
Polydimethysiloxane Modified Silica Nanochannel Membrane for Hydrophobicity-Based Molecular Filtration and Detection
复制标题
用于疏水性分子过滤和检测的聚二甲基硅氧烷改性二氧化硅纳米通道膜
DOI：
10.1021/acs.analchem.6b01866
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发表时间：
2016-08-02
影响因子：
7.4
通讯作者：
Su, Bin
中科院分区：
文献类型：
--
作者：
Lin, Xingyu;Zhang, Bowen;Su, Bin
在这项工作中，我们报告的二氧化硅纳米通道膜的制造不均匀改性的聚二甲基硅氧烷（PDMS），指定为PDMS-SNM，基于疏水性的分子过滤和检测。通过将疏水性PDMS低聚物空间选择性地蒸发到膜的顶表面和二氧化硅纳米通道的孔口上来完成改性。由于这种疏水性的疏水层和超小通道（直径2-3 nm）之下，只有小的疏水分子能够通过PDMS-SNM运输，而亲水性和大的分子被显著抑制。我们首次采用这种PDMS-SNM作为分子筛基质，用于选择性电化学检测牛奶样品中的疏水有机磷酸盐（OP），而无需预处理。PDMS-SNM修饰电极具有良好的分析性能和抗干扰能力。我们还制备了独立的PDMS-SNM，它由多孔通道组成，可以根据分子的疏水性以优异的选择性过滤分子。结果表明，2，4，6-三硝基甲苯和多巴胺可以分离，选择性系数高达335。此外，由于不均匀的纳米通道结构和超小的厚度，获得了非常高的疏水分子通过PDMS-SNM的通量，这比以前报道的高3-4个数量级。
We report in this work the fabrication of ultrathin silica nanochannel membranes inhomogeneously modified by polydimethysiloxane (PDMS), designated as PDMS-SNM, for hydrophobicity-based molecular filtration and detection. The modification was accomplished by spatially selective evaporation of hydrophobic PDMS oligomers onto the top surface of the membrane and orifice of silica nanochannels. Thanks to this hydrophobic ultrathin layer and beneath ultrasmall channels (2-3 nm in diameter), only small hydrophobic molecules are able to transport through the PDMS-SNM, whereas hydrophilic and large ones are remarkably inhibited. We first employed this PDMS-SNM as the molecular sieving matrix for selective electrochemical detection of hydrophobic organo-phosphates (OPs) in milk samples without pretreatment. The PDMS-SNM modified electrode displayed an excellent analytical performance and antifouling/anti-interference ability. We also prepared the free-standing PDMS-SNM consisting of perforated channels, which could filtrate molecules based on their hydrophobicity with an excellent selectivity. As demonstrated, 2,4,6 trinitrotoluene and dopamine could be separated with a selectivity coefficient as high as 335. Moreover, because of the inhomogeneous nanochannel structure and ultrasmall thickness, a remarkably high flux of hydrophobic molecules across the PDMS-SNM was obtained, which was 3-4 orders of magnitude higher than that reported previously.