Non-origami DNA for functional nanostructures: From structural control to advanced applications

The revolutionary idea that DNA can play a non-biological role in a material world has indeed become today's reality. Although much attentions have recently been paid to "structural DNA nanotechnology" centered on DNA origami, due to the need for DNA computation, hybridization and modification that are usually not easily accessed, reproduced, or manipulated, preparation of nanostructures using DNA origami may have yet set a threshold for researcher to advance their fields with functional nanomaterials. It is suggested that, consisting of a few nucleotides (base pairs), or readily obtained by a simple procedure, non-origami DNA itself has sufficiently rich chemical functionality, and afford sequence-programmed growth of hybrid nano-architectures made of DNA and interactive materials with base-resolution control, and that the potential of non-origami DNA in building functional nanostructures has been underestimated. We have investigated an impressive number of fundamental and application-orientated studies in the late few years, and been preparing the review of the state of research in various subdisciplines of functional nanostructures based on non-origami DNA, which involve fundamental interactions of DNA-inorganic species, DNA nanofabrication, electronic nanodevices, functional metal nanoparticles and chiral nanostructures as well. Applications for these nanostructures have been covered in fields ranging from plasmonic biosensing and electrical nanodevices to optical bioimaging and photocatalysis. In this review, we will start with the fundamentals in DNA-based nanofabrication, including structure, characteristics and handling of DNA. Then, the capability of morphological control by simple DNA molecules, the resultant nanostructures and novel properties will be discussed and compared. Particularly, we emphasized the potential of single DNA molecules in templating the growth of nanostructures with different compositions, such as electrical polymer/metal nanowires, plasmonic nanostructures, fluorescent quantum dots and chiral silica nanostructures. Furthermore, the advanced applications of the non-origami DNA-based functional nanostructures in a range of fields will be figured out, including nanoelectronics, therapeutics and photocatalysis. Finally, conclusions will be drawn, and perspectives will be given. This review should be important for the development of DNA nanotechnology and DNA-based nanomaterials in the next decade, and creation of new nanomaterials based on simple DNA molecules, and their expanded applications as well.