Synthesis and recognition of molecularly imprinted polymers for gastrodin based on surface-modified silica nanoparticles

A molecular imprinting material with high performance for recognizing Gastrodin (GAS) was prepared by adopting the novel surface molecular imprinting technique. Silica nanoparticles were first modified with 3- methacryloxypropyltrimethoxysilane (KH-570) as a carrier material. Then, GAS surface molecule-imprinted polymer (GAS-SMIP) were prepared by polymerization with methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the crosslinker. The equilibrium adsorptive experiments indicated that GAS-SMIP had significantly higher adsorption capacity for GAS than its nonimprinted polymers. Scatchard analysis revealed that two classes of binding sites were formed in GAS-SMIP with dissociation constants of 1.019 and 7.278 Îmol/mL, and the affinity binding sites of 17.82 and 83.11 Îmol/g, respectively. The selectivity coefficient of GAS-SMIP for GAS in respect to competition species obtained was 3.455, which revealed GAS-SMIP had excellent selectivity and site accessibility for GAS. Kinetic binding study showed GAS-SMIP adsorbed quickly in the first 40 min, and reached saturation adsorption at 1 h.