Customizable colloidosomes confining enzymes for continuous-flow biocatalysis

Tuning SiO 2 nanoparticle size creates uniform precise nanopores matching enzymes within colloidosome shells. • Hollow porous colloidosomes provide high-density enzyme sites, yielding dozens-fold higher efficiency than free CALB in batch. • Integrating CALB-colloidosomes into a continuous-flow reactor yields 21.3-fold efficiency and >85% stability after 200 h. Enzyme confinement at the molecular scale reveals catalytic performance that is previously unseen at the ensemble level, but all such delicate enzyme hosts now available encounter their intrinsic issues. Here, we present a mild, one-pot emulsification-directing approach to customize colloidosomes (CSs) with pores matching enzyme size as enzyme hosts for optimizing continuous-flow biocatalysis. By means of the dissolution-induced inside-out self-assembly, uniform and enzyme-matched pores can be readily achieved. Typically, 5.8-nm pores obtained using 22-nm SiO 2 nanoparticles (SiO 2 NPs) as building blocks are optimal for confining Candida antarctica lipase B (CALB, ∼5 nm), conferring 98.3% activity recovery and minimal leaching of only 2.1%. The catalytic efficiency of CALB-confined colloidosomes (CALB/CSs) is dozens of times higher than that of free CALB (fCALB) in batch mode. Moreover, a 21.3-fold catalytic efficiency was achieved by integrating robust CALB/CSs with a continuous-flow platform. Meanwhile, the desired long-term stability was confirmed, with over 85% of the initial efficiency maintained after 200-h of consecutive operation. This study offers a potentially generalizable strategy that establishes a CS platform as an enzyme-confined host that is competent for continuous flow manufacturing, hoping to unlock the full potential of enzymatic reactions. Customizable colloidosomes with uniform enzyme-matched pores are fabricated via a mild, one-pot emulsification-directed self-assembly. The colloidosome shell is composed of hexagonal close-packed SiO 2 nanoparticles that form uniform pores, whose size is easily tuned by the size of the SiO 2 nanoparticles and thus precisely customizable for target enzymes. The robust colloidosome hosts exhibit efficient catalytic efficiency and long-term stability in continuous-flow reactors. Download: Download high-res image (162KB) Download: Download full-size image