Fine-tuned mesoporous covalent organic frameworks for highly efficient low molecular-weight proteins separation

Covalent organic frameworks(COFs)are prominent porous materials for molecules separation due to their desirable structures.However,very few COFs are reported for the separation of macromolecules such as low molecular-weight(MW)proteins.Here,two stable mesoporous COFs(Azo-COF and Tp-COF)with highly crystallized frameworks are synthesized,and their pore sizes are slightly-regulated via elaborate selection of pyrene knots and amino linkages.Benefiting from the pore size difference less than 4 ?,the tandem utilization of these two COFs exhibits efficiently size-selective separation ability towards low MW proteins cytochrome c and myoglobin with small MW difference of 2 kDa,in which protein adsorption possibilities are verified by computational calculations together with confocal laser scanning microscopy(CLSM).Furthermore,a simple COF-based separation device is designed and prepared to achieve effective and low-consumption proteins separation.This work has offered an optimized synthetic strategy for fine-tuned mesoporous COFs and expanded their applications on macromolecules separation.