Bioactive MIL-88A framework hollow spheres via interfacial reaction in-droplet microfluidics for enzyme and nanoparticle encapsulation

Abstract

Functional bio-MOF hollow spheres with controlled size in the 35−2000 μm range were successfully synthesized by interfacial reaction using a continuous-flow droplet microfluidic system in a single step and one-flow strategy. The architecture of MIL-88A frameworks was extended from singleshell to double-shell hollow spheres. Moreover, various functional nanoparticles (silica, cobalt, and UiO-66(Zr) MOF) were directly encapsulated in the singleshell hollow spheres, while maintaining the functionality of the cargo. In particular, three kinds of enzymes (glycerol dehydrogenase, horseradish peroxidase, and acetylcholinesterase) were also encapsulated inside the singleshell hollow spheres under mild conditions. The catalytic activity and the superior recyclability of the encapsulated enzymes were demonstrated against free enzymes.