Abstract: In certain aspects, the present disclosure provides an enzyme inhibitory nanoparticle. The nanoparticle may comprise zinc oxide. The nanoparticle exhibits substantially reversible enzyme inhibition in the presence of an enzyme. In certain aspects, the shape of the nanoparticle may be a nanopyramid or a nanoplate/nanodisc. In other aspects, the present disclosure provides an antimicrobial material comprising a layer-by-layer (LBL) coating comprising a plurality of nanoparticles comprising zinc oxide. Each nanoparticle exhibits antimicrobial activity in the presence of bacteria. LBL coatings of ZnO-NP reduced Staphylococcal biofilm burden by >95%. The disclosure also provides methods of preparing an enzyme inhibitory or antimicrobial nanoparticles comprising zinc oxide.