Iniferter‐mediated grafting of molecularly imprinted polymers on porous silica beads for the enantiomeric resolution of drugs

Abstract

A surface-imprinted chiral stationary phase for the enantiomeric resolution of the antidepressant drug, citalopram, is presented in this work. N, N'-diethylaminodithiocarbamoylpropyl(trimethoxy)silane has been used as silane iniferter for the surface functionalization of the solid silica support. A molecularly imprinted polymer thin film, in the nm scale, was then grafted on the silanized silica using itaconic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linker in the presence of the template S-citalopram. The total monomer amount was calculated to obtain the desired thickness. Non-imprinted stationary phases were prepared similarly in the absence of S-citalopram. Characterization of the materials was carried out by scanning electron microscopy, thermogravimetric analysis, elemental analysis and Fourier transform infrared spectroscopy. Stationary phases have been applied to the chromatographic separation of the target. Conditions for best chromatographic resolution of the enantiomers were optimized, and it was found that a mobile phase consisting of a mixture of formate buffer (40 mM, pH 3) and acetonitrile (30:70 v/v) at 40 °C provided best results. Binding behaviour of the developed material was finally assessed by batch rebinding experiments. The obtained binding isotherm was fitted to different binding models being the Freundlich-Langmuir model, the one that best fitted the experimental data. The developed material has shown high selectivity for the target enantiomer, and the stationary phase could be undoubtedly exploited for chiral separation of the drug.

Chiral Separations by Capillary Electrophoresis and related Techniques with Different Chiral Selectors: A Review

“…In this study, some anti-depressant drugs were used as test compounds for enantiomeric separation. In another study, Gutierrez and his team presented a surface-imprinted CSP for the enantiomeric separation of citalopram [122]. N,N′-diethyl aminodithiocarbamoylpropyl (trimethoxy) silane was used as the silanizing agent for the surface modification of the solid silica support.…”

Strategies for Molecular Imprinting and the Evolution of MIP Nanoparticles as Plastic Antibodies—Synthesis and Applications

“…The separation field is continuously expanding driven by the needs of the pharmaceutical and chemical industries, and by the demands for water purification and waste remediation. By virtue of their high affinity and selectivity, MIPs have been employed as stationary phases in high performance liquid chromatography [120], capillary chromatography [121,122], and solid phase extraction [123]. The nano format however is not ideally suited for large-scale separation.…”

Key Enabling Technologies for Point-of-Care Diagnostics

“…Furthermore, MIPs show remarkable stability under storage in dry state at room temperature, with a shelf life of several years without loss of recognition capability [ 102 ]. The integration of MIPs into biosensing platforms could follow various pathways, thanks to the possibility to mold polymers in the shape of nanoparticles [ 103 ], bulk [ 104 ] or thin layers over the electrodes or beads’ surface [ 105 , 106 ]. The use of MIP-modified sensors is recently spreading in the field of POC devices thanks to the easy control of film thickness and good reproducibility.…”