Polymethylacrylic acid (PMAA) was grafted onto the surface of silica gel particles via the coupling effect of 3-methacryloxypropyl trimethoxysilane (MPS), and the grafting particle PMAA/SiO₂ was prepared. Then, the molecular imprinting towards the grafted PMAA was performed with alkaloid matrine which is originated from sophora alopecuroides linn as template molecule and ethylene glycol diglycidyl ether (EGDE) as crosslinking agent by using the novel surface-molecular imprinting technique established by our research group, and the matrine molecule-imprinted material MIP-PMAA/SiO₂ was prepared. With another alkaloid, cytisine which is also contained in sophora alopecuroides linn, as a contrast compound, both static and dynamic methods were adopted to study the binding properties and molecule recognition character of MIP-PMAA/SiO₂ for matrine. The experiment results show that MIP-PMAA/SiO₂ have specific recognition selectivity and excellent binding affinity for matrine. Besides, MIP-PMAA/SiO₂ has excellent elution property, with a acetic acid solution containing NaCl as the eluent, the desorption ratios of matrine reach 99.77% in 17 BV.

Key words: polymethylacrylic acid, silica gel, molecular imprinting, surface imprinting, matrine, molecule recognition