The biological world has unparalleled abilities to control structures, functions, reactions, and energy transfer with great efficiency and accuracy. We are interested in biomimetic chemistry to “abstract good design from nature.” One of our main research goals is to design molecules that functionally mimic certain biological systems, and in turn to prepare molecules, polymers, and materials that have useful and superior properties. Our imprinted nanoparticles mimic natural antibodies in their molecular recognition of small-molecule drugs, peptides, and carbohydrates. They serve as excellent supramolecular hosts, specific biomimetic sensors, and smart materials useful for chemistry and biology. Our enzyme-mimetic catalysts carry out highly selective chemical transformations in water under mild conditions. They can hydrolyze less reactive alkyl esters with exquisite selectivity while more reactive aryl esters stay intact in the same solution. They remove specific glycans on the surface of cells under physiological conditions. They cleave cellulose with enzyme-rivaling activities but are far more stable than enzymes at higher temperatures or in nonaqueous solutions.