| 초록 |
The goal of biomimetic chemistry to emulate the structural and functional aspects of natural enzymes. Much effort has been invested in the synthesis of (supra)molecular models that are more stable and cost efficient than their natural counterparts. The functions of enzymes are governed by enzyme dynamics, and enzymes are typically larger than their substrates. The reaction environment it exposes is so different from the surrounding solvent that it may be considered a solid catalyst. The radii of enzymes and nanoparticles are comparable, and the interactions of enzymes and nanoparticles with molecules in solution are comparable as well. Typically, nanoparticles are stabilized in solution with ligands or polymers and their activity and selectivity are determined by characteristics such as size and the facets they expose. The most active particles in catalysis have diameters of a few nanometers, i.e. they contain only a few hundred atoms. Their reactivity may even be higher than that of enzymes, because any surface site can be catalytically active. Therefore, enzyme mimetic catalysis with nanoparticles has been successful in cases, where small species (peroxides, superoxides or sulfites) are involved and steric demands play only a minor role for the specificity of the reaction. Different from most enzymes, nanoparticle mimics can also operate in nonaqueous systems, and they are available by cost efficient synthesis up to industrial scale. Many examples (V2O5, CeO2, MoO3, Fe3O4, Cu(OH)2 or ternary oxides from the spinel and perovskite family) show catalytic activities and stabilities comparable or superior to those of natural enzymes. We highlight recent progress in the field and illustrate new applications in antifouling, wound healing, water and gas purification, or fiber staining. |
