Fabrication and imaging of nanometer-sized protein patterns

This Letter describes a new method for production of nanometer-sized protei n patterns with precise control of the size and geometry. Self-assembled mo nolayers (SAMs) are first patterned using nanografting, an atomic force mic roscopy (AFM)-based lithographic method. Methyl-terminated n-alkanethiols s erve as matrix layers within which nanopatterns of thiols with carboxylate or aldehyde terminal groups are fabricated. By controlling solution conditi ons, we selectively immobilize proteins on the patterned areas, through eit her electrostatic interactions or covalent binding. In our approach, AFM ti ps are used for both fabrication and characterization. AFM allows patterned SAMs and proteins to be visualized in situ. The individual proteins within the nanopatterns and their orientations can be clearly resolved from the A FM images.