A covalent capillary coating of diazoresin and polyglycerol dendrimer for protein analysis using capillary electrophoresis.

Overcoming proteins adsorption on the inner surface of capillary has attracted increasing attention recently. By using the unique photochemistry reaction of diazoresin (DR), a new covalent capillary coating was prepared on the fused-silica capillary through layer-by-layer self-assembly of DR with polyglycerol (PG) dendrimer. The separation performance of covalently DR/PG-dendrimer coated capillary noticeably exceeded the bare capillary and the noncovalently linked DR/PG-dendrimer capillary. A baseline separation of lysozyme, myoglobin, bovine serum albumin, and ribonuclease A was achieved using CE within 20 min. Besides, the covalently linked DR/PG-dendrimer coating has the remarkable stability and reproducibility. Especially, compared with the traditional method which use highly toxic and moisture-sensitive silane coupling agent, this method seems to be a simple and environmental friendly way to prepare the covalently coated capillaries for CE.