With the great progress that has been made in the synthesis and assembly of nanomaterials during the past decades, there has been an ever-increasing interest in developing new methods to selectively manipulate nanomaterials that function as nanomachines [1] for promising applications in nanomechanics, nanoelectronics, nanobiotechnology, etc. To precisely control the nanomachines, both quantitative and kinetic studies of the manipulation processes are indispensable because they would provide not only determinative proof of the successful accomplishment of the manipulation, but also a deeper understanding of the process and a solid basis for further applications. One of the most promising ways to accomplish these aims is to fabricate nanomachines on planar substrates because, firstly, with the development of advanced lithographic techniques, predesigned micro or nanopatterns can be formed, which provides a fascinating way to integrate top-down and bottom-up techniques to fabricate nanomachines. [2] Secondly, with the development of modern surface techniques, different facile, reliable methods have been developed to characterize the nanostructures on planar substrates, [3] which would allow the convenient study of the surfaces quantitatively and in real time. [4] Formed from four bases, A, T, C, and G, DNA molecules provide unlimited base sequences for selective molecular recognition and interaction. DNA has been widely applied to the assembly of nanomaterials into different nanostructures based on DNA hybridization reactions. [5] By combining DNA assembly and dissociation processes, exciting nanomachines may be developed. [6] Recently, much attention has been paid to the development of new methods for the disassembly of DNA-directed nanostructures. Compared with other disassembly methods such as use of temperature, [7] enzymes, [8] and aptamers, [9] the DNA displacement reaction (DDR) [10] shows some unique advantages. It provides a highly selective way to disassemble the nanostructures without the limitation of specific DNA sequences required by enzymes and aptamers. In addition, DNA sequences with similar melting temperatures could also be distinguished. Therefore, DDR may provide a general, facile, and highly selective method to manipulate DNA-assembled nanostructures.