Simultaneous targeted immobilization of anti-human IgG-coated nanotubes and anti-mouse IgG-coated nanotubes on the complementary antigen-patterned surfaces via biological molecular recognition.

Introduction of self-assembly in nanometer-sized building blocks is expected to accomplish bottom-up fabrications in a more reproducible, efficient, and economic manner; however, it is necessary to selectively place multiple types of nano-building blocks (e.g., metal nanotubes and semiconductor nanotubes) at specific locations on surfaces with high precision and reproducibility for more complex nanometer-scale device assemblies. Biological molecular recognition such as antibody-antigen bindings may be suitable to use in the building-block assembly since nature always assembles materials with complex functions and structures at room temperature reproducibly. Our approach is to immobilize antibody-coated nanotubes at specific complementary binding positions patterned on surfaces. To demonstrate this hypothesis, two types of nanotubes coated with different antibodies were anchored selectively onto their complementary antigen areas, patterned by tips of atomic force microscope (AFM). Because those nanotubes can be coated by various metals and semiconductors with controlled morphologies, this outcome opens the possibility to accomplish the proposed unconventional device fabrication methodology that antibody nanotubes coated with different types of metals/semiconductors can be self-assembled on antigen-patterned surfaces via biological molecular recognition.