Synthesis and characterization of ammonium functionalized porous poly(glycidyl methacrylate-co-ethylene dimethacrylate) monoliths for microscale analysis and its application to DNA purification.

A systematic study of parameters affecting the nucleophilic addition of secondary and tertiary amines on reactive epoxy groups was conducted on porous polymer monoliths. Reaction of small amines like diethylamine (DEA) or triethylamine (TEA) on poly(glycidyl methacrylate-co-ethylene dimethacrylate) monoliths (poly(GMA-co-EDMA)) allows to prepare anion exchange media. This study aimed to determine optimal and suitable conditions to prepare anion-exchange porous monolith inside 100 microm internal diameter capillary. The reaction kinetic of amine nucleophilic addition on porous poly(GMA-co-EDMA) monoliths was followed by FTIR-ATR spectroscopy. The reactivity of such epoxy-functionalized porous polymers was first determined through a study in pure amine solutions. Thereafter, conditions of reactions (i.e., temperature and time of reaction, solvent composition, concentration of amine) with respect to its further implementation at nanoscale, were optimized through a factorial analysis. The optimization allowed extending conversion yields of epoxy groups up to more than 90% in dilute amine solution within less than 4 hours of reaction for TEA addition. This ion-exchange support with respect to the in-situ light-addressable process of elaboration is specifically designed to be incorporated as biomolecular sample preparation module in microsystem devices. The high loading capacity obtained for the preconcentration of DNA demonstrate the attractivity of this functionalized polymeric porous monolith as solid-phase support to improve the quantity and the efficiency of DNA extraction applied into microscale format like capillaries or lab-on-chip.