Preparation of a novel light-sensitive copolymer and its application in recycling aqueous two-phase systems

Aqueous two-phase systems (ATPSs) are potential bioseparation techniques in industry. However, a key problem is that aqueous two-phase systems could not be effectively recycled to result in high cost and environment pollution. Recently, how to prepare recycling copolymers forming aqueous two-phase systems is focused on in the area. In this study, a light-sensitive copolymer (PNNC) was synthesized by using N-isopropylacrylamide (NIPA), N-vinyl-2-pyrrolidone (NVP), chlorophyllin sodium copper salt (CHL) as monomers. The copolymer PNNC can form ATPSs with another novel pH-sensitive copolymer (PADB) which was synthesized by co-worker in our laboratory. Over 98% of the PNNC copolymer could be recovered by using laser radiation at 488 nm. The copolymer PADB could be recovered by adjusting the isoelectric point (pI) to 4.1, with a recovery of 97%. Bovine serum albumin (BSA) and Tyr were partitioned in the PNNC–PADB aqueous two-phase systems to examine the systems. It was found that partition coefficient of BSA and L-Tyr could reach 4.1 and 0.12 in the systems, respectively.