Fig. 1.

Fabrication and characterization of hollow silica micromotors. a Schematic representation of the fabrication process of HSMC functionalized with enzymes to obtain HSMM that catalyze substrates (S) into products (P) resulting in self-propulsion. PS: polystyrene, TEOS: tetraethylorthosilicate, APTES: 3-aminopropyltriethoxysilane, DMF: dimethylformamide, GA: glutaraldehyde. Enzyme structures are extracted from RCSB PDB (see Supplementary Note 3). b SEM and c TEM image of HSMC showing the hole and silica bulks. d False color TEM image showing HSMC thickness. e Fluorescence (Ex/Em = 520/580 nm) of enzymatic HSMM treated with Krypton™ protein staining dye