Light-controlled chemoenzymatic immobilization of proteins towards engineering of bioactive papers.

Efficient and reliable methods for the generation of bioactive papers are of growing interest in view of point-of-care testing devices that do not require extensive analytical equipment. Herein, we report on immobilization of functional proteins onto paper fibers using a modular chemoenzymatic approach. The synthetic strategy relies on the combination of highly efficient spatially controllable photo-triggered cycloaddition followed by site-specific sortase A-catalyzed transamidation. This site-directed and regiospecific method allowed unidirectional and covalent immobilization of several proteins possessing different functional properties with ramifications for application in paper-based diagnostics.