Antibody-mimetic peptoid nanosheets for molecular recognition.

The ability of antibodies to bind a wide variety of analytes with high specificity and high affinity make them ideal candidates as molecular recognition elements for chemical and biological sensors. However, their widespread use in sensing devices has been hampered by their poor stability and high production cost. Here we report the design and synthesis of a new class of antibody-mimetic materials based on functionalized peptoid nanosheets. A high density of conformationally constrained peptide and peptoid loops are displayed on the surface of free-floating nanosheets to generate an extended, multivalent two-dimensional material that is chemically and biologically stable. The nanosheet serves as a robust, high-surface area scaffold upon which to display a wide variety of functional loop sequences. The functionalized nanosheets were characterized by atomic force microscopy, X-ray diffraction, and X-ray reflectivity measurements, and were shown to serve as substrates for enzymes (protease and casein kinase II), as well as templates for the growth of defined inorganic materials (gold metal).