Preparation of poly(N-isopropylacrylamide)-grafted well-controlled 3D skeletal monolith based on E-51 epoxy resin for protein separation

A novel type of poly(N-isopropylacrylamide) grafted E-51 epoxy-based monoliths in a 100 mm × 4.6 mm I.D. stainless steel column with well-controlled three-dimensional skeletal structures has been prepared and proposed for the separation of proteins. The grafted PNIPAAm chain via surface-initiated atom transfer radical polymerization was successfully performed. The proposed method provided a new route to modify the E-51 epoxy-based monoliths for widening their applications. Meanwhile, the temperature and the salt concentration responses of the grafted monolithic columns were investigated. Under the salt gradient, six proteins were well separated in hydrophobic interaction mode. Moreover, for further confirming the application of the prepared monolith was meaningful for proteome analysis in actual system, the separation of human serum sample was performed.