Affinity monolith preconcentrators for polymer microchip capillary electrophoresis

Abstract

Developments in biology are increasing demands for rapid, inexpensive, and sensitive biomolecular analysis. In this study, polymer microdevices with monolithic columns and electrophoretic channels were used for biological separations. Glycidyl methacrylate-co-ethylene dimethacrylate monolithic columns were formed within poly(methyl methacrylate) microchannels by in situ photopolymerization. Flow experiments in these columns demonstrated retention and then elution of amino acids under conditions optimized for sample preconcentration. To enhance analyte selectivity, antibodies were immobilized on monoliths, and subsequent lysozyme treatment blocked nonspecific adsorption. The enrichment capability and selectivity of these affinity monoliths were evaluated by purifying fluorescently tagged amino acids from a mixture containing green fluorescent protein (GFP). Twenty-fold enrichment and 91% recovery were achieved for the labeled amino acids, with a <25,000-fold reduction in GFP concentration, as indicated by microchip electrophoresis analysis. These devices should provide a simple, inexpensive, and effective platform for trace analysis in complex biological samples.

Sample preconcentration in microfluidic devices

“…One strategy to address this problem is to immobilize highly specific enzymes or antibodies on the SPE monoliths. For example, antibodies were immobilized on an acrylate-based SPE monolith in the microchannel for improving both the sensitivity and the selectivity for amino acids (Yang et al 2008). In this study, the glycidyl methacrylate (GMA)-co-EDMA was first photo-polymerized in the microchannel, followed by introducing amine groups on this monolith surface by ethylenediamine (EDA) reaction with the GMA epoxy groups.…”

My favorite materials: Porous polymer monoliths

“…A lot of work has been done in the application of monoliths in microfluidic devices. Protein preconcentration [45][46][47][48], frits for retaining particles [49], electrospray emitters for ESI-MS [50,51], thermally actuated valves [52,53], chip electrochromatography [54], and micromixers [55] are only a few examples picked from the numerous publications.…”

Bioaffinity chromatography on monolithic supports

“…This affinity monolith microchip can be used thrice for capturing, eluting and separating FITC-HSA and FITC-IgG from a mixture containing FITC-HSA, FITC-IgG and GFP (latter as interfering protein, no FITC group) with an elution efficiency above 80%. The same group employed an anti-FITC monolithic polymethyl methacrylate microchip to selectively extract FITC-labeled amino acids (glycine, phenylalanine, and arginine) from a mixture [128]. The epoxy groups in the 5 mm long GMA monolith were converted to NHS groups and subsequently antibodies were attached via SH groups.…”