香兰素分子印迹微球的制备及识别机理研究

摘要/Abstract

摘要： 以香兰素(Van)为模板、甲基丙烯酸(MAA)为功能单体、偶氮二异丁腈(AIBN)为引发剂和乙烯二醇二甲基丙烯酸酯(EDMA)为交联剂，采用沉淀聚合法合成一种新型的对Van有特异识别功能的分子印迹聚合物微球(MIPs)。通过UV、傅里叶变换红外光谱仪(FT-IR)和1H NMR光谱法研究模板与功能单体之间的相互作用和识别机理，采用扫描电镜(SEM)考察MIPs表面形态，通过平衡和等温吸附实验对MIPs和非分子印迹微球(NIPs)吸附性能进行研究。结果表明：MAA与Van之间通过氢键相互作用，MIPs具有表面光滑的规则球状结构，MIPs对Van的吸附和识别能力远高于NIPs，并且在120min后达到吸附平衡状态，Scatchard分析表明在MIPs上形成了均匀的对Van有特异性的结合位点，最大表观吸附量Qmax和平衡离解常数Kd分别为7.357μmol/g和4.243×10-5mol/L；选择性分离、分子印迹固相萃取(MIP-SPE)和HPLC实验分析表明，MIPs对Van具有很好的分离和富集能力。

关键词: 分子印迹微球, 香兰素, 识别机理, 沉淀聚合, 固相萃取

Abstract: Molecularly imprinted microspheres (MIPs) were synthesized by precipitation polymerization using vanillin as template molecule, methacrylic acid (MAA) as functional monomer, azodiisobutyronitrile (AIBN) as initiator and ethylene glycol dimethacrylate as cross-linker. The interaction of vanillin with MAA and the recognition mechanism of vanillin MIPs were studied by UV spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and 1H-NMR, and their surface morphology was observed under a scanning electron microscope (SEM). Equilibrium adsorption and isothermal adsorption experiments were carried out to investigate the vanillin-binding capacities of MIPs and non-molecularly imprinted polymers (NIPs). Smooth and regularly shaped MIPs were formed from the hydrogen bonding interaction between vanillin and MAA. They could adsorb and recognize vanillin much better than NIPs and adsorption equilibrium was reached after 120 min. Scatchard analysis showed that a homogenous distribution of vanillin-specific recognition sites were found in the MIPs, and the dissociation constant (Kd) and apparent maximum binding capacity (Qmax) were 4.243 × 10-5 mol/L and 7.357 μmol/g, respectively. The results of selective separation, solid phase extraction (SPE) and HPLC analysis indicated that these MIPs were effective in separating and enriching vanillin.

Key words: molecularly imprinted microsphere, vanillin, precipitation polymerization, recognition mechanisms, solid phase extraction

中图分类号:

O657

王深旗1，彭海龙1,2，熊?华1,*，阮?霞1，黄声芳1，董丽玲1. 香兰素分子印迹微球的制备及识别机理研究[J]. 食品科学, 2012, 33(23): 1-7.

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