In Situ Encapsulation of Cellulase in a Novel Mesoporous Metal-Organic Framework

In situ encapsulation of cellulase in conventional metal-organic frameworks (MOFs) is restrained by harsh preparation conditions and the rather small pores of the frameworks. Herein, We developed a mesoporous Zn-based MOF (Zn-mIm) prepared under mild conditions is well-suited for in situ encapsulation of cellulase. In brief, cellulase is encapsulated through coprecipitation of cellulase and Zn-mIm precursors, identified as cellulase@Zn-mIm. This approach enhances the binding between cellulase and Zn-mIm. The cellulase loading also significantly increases, and the highest loading is up to 350 mg g(-1). Moreover, cellulase@Zn-mIm shows superior tolerance to basic environments and retains 65% of its activity at pH 8, whereas that of free cellulase drops to only 10%. Cellulase@Zn-mIm also exhibits good recyclability and retains 77% of its activity after four cycles. Furthermore, the introduction of cellulase leads to structural defects during Zn-mIm preparation, resulting in the formation of large pores, which facilitate mass transfer and thus enhance enzymatic efficiency.