Construction of imprint sites in mesopores of SBA-15 via thiol-ene click reaction
This paper reports a new strategy for preparation of 2D molecularly imprinted materials (MIM) through the exploitation of thiol-ene click chemistry. 2D MIM for cholesterol was prepared using cholesterol as the template, acrolyl-modified β-cyclodextrin (acrolyl-β-CD) as the functional monomer, and thiol-modified SBA-15 (thiol-SBA-15) as the supporter. In this method, acrolyl-β-CD molecules were assembled around the templates by formation of template–monomer inclusion compounds. Then the acrolyl-β-CD molecules were anchored to the walls of the mesopores of SBA-15 via the thiol-ene click chemistry. After removal of the template molecules, the resulting recognition sites were formed in the mesopores of SBA-15. TEM, XRD, and N2 adsorption–desorption analysis results demonstrated that the synthesized MIM had a highly ordered mesoporous structure. Results from FT-IR revealed that acrolyl-β-CDs have been successfully conjugated to SBA-15. The density of β-CDs attached on the MIM is determined by EA and TGA. The equilibrium binding amounts of MIM and non-imprinted materials (NIM) for cholesterol are 53.50 and 25.24 μmol/g, respectively. The 2D MIM exhibited binding affinity and specificity for a group of analytes which have similar size and shape to those of template. The application of the prepared materials as stationary phases in thin layer chromatography was investigated preliminarily. The imprinted materials had higher retention ability for the template than the NIM. The retention factors (R f) of cholesterol on MIM and NIM are 0.62 and 0.81, respectively. The solid phase extraction of cholesterol using MIM as the adsorbent was further investigated. The recoveries of the molecularly imprinted solid phase extraction column for cholesterol were 77.1–94.7 % with relative standard deviations (RSD) of 2.25–6.78 %.
KeywordsMesoporous Silica Cholic Acid Thermal Gravimetric Analysis Functional Monomer Template Molecule
The authors thank the National Natural Science Foundation of China (No. 21472038 and 21505035), the Project of Education Department of Hunan Province (No. 15A027), the Natural Science Foundation of Hunan Province (No. 2016JJ3028), the Aid programs for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province, and the Key Discipline of Hunan Province for the financial support of the research.
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