Fabrication of 17β-estradiol imprinted silica with high recognition capability using a sol-gel method

• Main Authors: Hou, Ching-Jung, 侯棈榮
• Other Authors: Chang, Sue-Min
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/21560662556097050337

碩士 === 國立交通大學 === 環境工程系所 === 98 === 17β-estradiol (E2) is a phenolic steroid hormone of endocrine disrupted contaminants. It has adverse effects and cause abnormality on the endocrine system of wildlife and humans. The high selectivity and affinity of molecularly imprinted polymers (MIPs) toward target molecules make them receive much attention on separation and sensing of E2. The aim of this study was to develop and characterize E2 imprinted organic-inorganic hybrid silica using a sol-gel process. Phenyltrimethoxysilane (PTMOS) and 3-aminopropyltriethoxysilane (APTES) were used as functional monomers to selectively bind E2 via π-π stacking interactions and hydrogen bonding, respectively. In addition, tetraethoxylsilane (TEOS) was used as a cross-linker to polymerize the highly porous gels. To enhance the mechanical elasticity, methyltrimethoxysilane (MTMOS) was incorporated into the gels. The recipes and sol-gel parameters were optimized to reach the highest imprinted capabilities. The imprinted material with the optimal TEOS/PTMOS/APTES/MTMOS/E2 molar ratio of 20/2/2/2/1 exhibited an adsorption capacity of 0.36 mg/g and an imprinted factor of 1.8 in acetonitrile. The PTMOS and APTES dominated the recognitions and binding quantities, respectively. The imprinted material showed the highest adsorption capacity of 0.44 mg/g and the imprinted factor of 1.9 in acetonitrile when the sol-gel process was proceeded at water/Si=3.3 and pH=3. Moreover, the adsorption capacity was remarkably enhanced to 28.2 mg/g in toluene. After removal of E2, the specific surface areas and pore volume of imprinted silica was increased significantly from 288 m2/g to 658 m2/g and 0.25 cm3/g to 0.59 cm3/g, respectively. In addition, the adsorption equilibrium time was 4 hr for the imprinted polymers. The imprinted silica performed high selectivity factor of 3.1 for 1-naphthol and 2.3 for nonylphenol in competitive adsorption systems. These results clearly demonstrated that the imprinted effect was successfully conducted in the organic-inorganic silica hybrids through the sol-gel process.