Using ZIF-8 as stationary phase for capillary electrophoresis separation of proteins.

Recently, the separation of proteins has received much attention, although many techniques require expensive instrumentation and trained analysts. In this work, a low-cost, effective, and environmental friendship capillary electrophoresis (CE) for proteins separation was first time introduced. The ZIF-8 with outstanding properties of large surface area, and accessible tunnels and cages were coated the inner surface of silica capillary as a separation media by electrostatic interaction. The fast baseline separation of Lys, CC, BSA and RNase A can be obtained within 10 min using the ZIF-8 nanocrystals coated capillary column under the optimum separation conditions. Meanwhile, this system showed good reproducibility and stability. Using L-glutamic acid as the selector ligand, the D- and L-phenylalanine were successfully separated by the ZIF-8 nanocrystals coated capillary column. Furthermore, the method was also applied to separate egg white proteins, and three main proteins were separated in a single run.