Porous polydimethylsiloxane monolith for protein digestion

This paper reports the preparation of porous polydimethylsiloxane (PDMS) monolith and its application in protein digestion. Glass microbubbles were used as the template to prepare the porous PDMS monolith. The PDMS monolith presented the interconnected porous structure with a high specific surface area. The average pore size of the porous PDMS monolith was 51 μm with the interconnected pores of 15 μm. Trypsin was immobilized on the inner pore surface of the PDMS monolith with high stability and high density by using the polydopamine as the primer with the advantage of the mild and efficient immobilization condition. Compared with the 12 hour in-solution digestion, the porous PDMS monolith could digest the protein within 15.6 minutes. The high digestion efficiency by continuously flowing the model protein solutions through the porous PDMS monolith with immobilized trypsin demonstrated the value of the porous PDMS monolith as a solid support for enzyme microreactors.