Microfluidic carbonylated protein capture

We report a proof of principle study for the use of oxalyldihydrazide as a crosslinker for enrichment of carbonylated proteins within a microfluidic chip. Surface modification steps are characterized and analyzed using analytical techniques. We use in vitro oxidized bovine serum albumin as a model protein for testing the selectivity and specificity of the methodology for carbonylated proteins. We demonstrate high specificity for our target protein, obtaining 100% capture of our target molecule during the first three minutes of continuous injection. After 30 minutes of continuous loading, the device captures half of the targeted molecules. Elution of the proteins is confirmed qualitatively. Under the flow conditions used in this experiment, nearly 300 ng of proteins can be enriched prior to chip saturation. This report suggests the validity of using immobilized oxalyldihydrazide on a microchip as an enrichment methodology for low abundance proteins in a sample.