Inverse Opals of Molecularly Imprinted Hydrogels for the Detection of Bisphenol A and pH Sensing
Inverse Opals of Molecularly Imprinted Hydrogels for the Detection of Bisphenol A and pH Sensing
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DOI：
10.1021/la202840y
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发表时间：
2012-01-10
期刊：
影响因子：
3.9
通讯作者：
Mangeney, Claire
中科院分区：
文献类型：
--
作者：
Griffete, Nebewia;Frederich, Hugo;Mangeney, Claire
采用胶体晶体模板法制备了反蛋白石分子印迹聚合物膜。二氧化硅颗粒的胶体晶体是通过Langmuir-Blodgett技术构建的，从而可以完美地控制膜厚度。在双酚A（BPA）的存在下在胶体晶体的间隙中聚合并除去所用的模板提供了3D有序的大孔甲基丙烯酸基水凝胶膜，其中衍生自双酚A的纳米腔分布在反蛋白石水凝胶的薄壁内。研究了非印迹聚合物（NIPs）和分子印迹聚合物（MIPs）的平衡溶胀特性随pH和双酚A浓度的变化规律，同时采用交联网络结构理论分析了本体水凝胶的分子结构.该研究表明，与NIP相比，BPA提取后MIP中的纳米孔（筛目）尺寸增加，这与模板分子的分子印迹留下的纳米腔的存在一致。发现所得的反蛋白石显示大响应外部刺激（pH或BPA）与布拉格衍射峰位移取决于水凝胶膜厚度。因此，膜厚度被证明是一个关键参数，用于提高反蛋白石水凝胶膜沉积在基板上的传感能力。
Inverse opal films of molecularly imprinted polymers (MIP) were elaborated using the colloidal crystal template method. The colloidal crystals of silica particles were built by the Langmuir-Blodgett technique, allowing a perfect control of the film thickness. Polymerization in the interspaces of the colloidal crystal in the presence of bisphenol A (BPA) and removal of the used template provides 3D-ordered macroporous methacrylic acid-based hydrogel films in which nanocavities derived from bisphenol A are distributed within the thin walls of the inverse opal hydrogel. The equilibrium swelling properties of the nonimprinted (NIPs) and molecularly imprinted polymers (MIPs) were studied as a function of pH and bisphenol A concentration, while the molecular structures of the bulk hydrogels were analyzed using a cross-linked network structure theory. This study showed an increase in nanopore (mesh) size in the MIPs after BPA extraction as compared to NIPs, in agreement with the presence of nanocavities left by the molecular imprints of the template molecule. The resulting inverse opals were found to display large responses to external stimuli (pH or BPA) with Bragg diffraction peak shifts depending upon the hydrogel film thickness. The film thickness was therefore shown to be a critical parameter for improving the sensing capacities of inverse opal hydrogel films deposited on a substrate.