Biological bottom-up assembly of antibody nanotubes on patterned antigen arrays

Application of biotechnology in nanofabrication has an advantage to produce functional building-block materials that may not have synthetic counterparts. Here we introduced a new type of building block, antibody nanotubes, and demonstrated anchoring them on complementary antigen arrays via antibody-antigen recognition. Biological recognition between the antibody nanotubes and the antigen arrays permitted recognition-driven assembly of ordered nanotube arrays. The array of antigens was written by using the tip of an atomic force microscope (AFM) on alkylthiol self-assembled monolayer (SAM)-coated Au substrates via nanografting. After antigens were immobilized onto the shaved regions of the alkylthiol SAMs with the AFM tip, antibody nanotubes, produced by incubating antibodies in template nanotube solutions, were selectively attached onto the antigen regions. This technique is very useful when multiple building blocks are necessary to address specific locations on substrates because simultaneous immobilization of multiple antibody nanotubes at specific complementary binding positions can be achieved in a single process.