Molecularly imprinted polymer functionalized silica nanoparticles for enantioseparation of racemic tryptophan in aqueous solution.

Abstract

A method has beendeveloped for preparation of surface molecularly imprinted polymer functionalized silica nanoparticles (SiO2@MPS@MIP). Firstly, the silica nanoparticles are prepared by a one-pot sol-gel method using tetraethylorthosilicate and 3-methacryloxypropyltrimethoxysilane as functional monomers. Next, the template molecule (L-Trp) is self-assembled with the functional monomer (acrylamide). Finally, SiO2@MPS@MIP are prepared using N,N'-methylenebisacrylamide as the cross-linker. The prepared SiO2@MPS@MIP have an average diameter of about 6.3 ± 1.2nm. They exhibit good selectivity toward L-Trp with an imprinting factor of 6.3. The adsorption isotherm data was well described by the Langmuir model. The maximum adsorption capacities of SiO2@MPS@MIP for L-Trp and D-Trp were calculated to be 11.1 ± 0.9 and 2.66 ± 0.16mgg-1, respectively. An enantiomer excess value of 100% was achieved after adsorption of racemic Trp by the material. The work suggests that SiO2@MPS@MIP are a promising material for enantioseparation of Trp racemate in aqueous media. Graphical abstract.