Dip-pen nanolithography(DPN) has been developed to pattern monolayer film of various molecules in submicrometer dimensions through the controlled movement of ink-coated atomic force microscopy(AFM) tip on a desired substrate, which makes DPN a potentially powerful tool for making the functional nanoscale devices. In this letter, using direct-write dip-pen nanolithography to generate nanoscale patterns of poly-L-lysine on mica was described. Poly-L-lysine molecules can anchor themselves to the mica surface through electrostatic interaction force, so stable poly-L-lysine patterns, such as square, line, circle and cross, could be obtained on freshly cleaved mica surface. From AFM image of the patterned poly-L-lysine nanostructures on mica, we know that poly-L-lysine was flatly bound to the mica surface. These oriented patterns of poly-L-lysine on mica can provide the prospect of building functional nanodevices and offer new options for this technique in a variety of other significant biomolecules.
