Enzyme-Powered Porous Micromotors Built from a Hierarchical Micro- and Mesoporous UiO-Type Metal–Organic Framework

Here, we report the design, synthesis, and functional testing of enzyme-powered porous micromotors built from a metal–organic framework (MOF). We began by subjecting a presynthesized microporous UiO-type MOF to ozonolysis, to confer it with mesopores sufficiently large to adsorb and host the enzyme catalase (size: 6–10 nm). We then encapsulated catalase inside the mesopores, observing that they are hosted in those mesopores located at the subsurface of the MOF crystals. In the presence of H2O2 fuel, MOF motors (or MOFtors) exhibit jet-like propulsion enabled by enzymatic generation of oxygen bubbles. Moreover, thanks to their hierarchical pore system, the MOFtors retain sufficient free space for adsorption of additional targeted species, which we validated by testing a MOFtor for removal of rhodamine B during self-propulsion. This work was supported by BIST-IGNITE (MOFtors), the Spanish MINECO (project RTI2018-095622-B-I00), the Catalan AGAUR (project 2017 SGR 238), and the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 866348: iNanoSwarms). It was also funded by the CERCA Program/Generalitat de Catalunya. ICN2 is supported by the Severo Ochoa program from the Spanish MINECO (Grant No. SEV-2017-0706). Y.Y. acknowledges the China Scholarship Council for scholarship support. X.A. thanks the Spanish MINECO for the Severo Ochoa program (SEV-2014-0425) for the PhD fellowship (PRE2018-083712).