The advancement of nanotechnology has ushered in an era where controlling the three-dimensional (3D) nanoarchitecture of inorganic materials becomes essential for harnessing their novel mechanical, optical, and electronic properties. This paper explores the innovative use of DNA-programmable assembly as a versatile tool for creating 3D ordered inorganic frameworks. By leveraging the unique properties of DNA frameworks as templates, we successfully demonstrate the nanofabrication of various inorganic materials, including metals, metal oxides, semiconductors, and their composites. This work lays a foundational step toward establishing a new paradigm in 3D nanoscale lithography.
The relentless march of technology in the field of electronics, photonics, and sensing has historically leaned heavily on planar fabrication techniques, primarily lithographic methods. However, the growing demand for advanced materials in applications like optical and mechanical metamaterials, neuromorphic computing, and energy materials necessitates a shift toward 3D framework organization with nanoscale precision. While additive manufacturing and multistep lithography have made significant strides, they fall short in the sub-30-nm range and in accommodating a diverse range of materials. Self-assembly methods using biomolecules, surfactants, and nanoparticles offer great structural diversity but often lack the ability to prescribe specific nanoscale architectures. In recent years, DNA-based assembly has emerged as a potent method for organizing matter at the nanoscale. DNA origami, in particular, offers unprecedented programmability in shape, size, and interaction dynamics, making it an ideal candidate for the rational design of complex 3D structures. However, to fully harness these DNA-based materials in practical applications, it is crucial to translate these organic frameworks into robust, functional inorganic architectures. The concept of using DNA as a template for inorganic material growth is not new. Historically, the focus was on DNA metallization for applications in molecular electronics. However, these approaches often led to uncontrolled nucleation and growth. Recent advances in DNA silication have broadened the scope of potential applications, especially in environments that demand high durability.
A new study led by Professor Oleg Gang from Columbia University and published in Science Advances used of ex situ organic-inorganic hybridization techniques, namely liquid-phase infiltration (LPI) and vapor-phase infiltration (VPI), to convert DNA frameworks into functional inorganic structures. These methods are not only effective in retaining the intricate DNA-prescribed architecture but also allow for the integration of a wide range of materials, including various metals and metal oxides. The authors began with the synthesis of DNA origami structures, forming precise 3D frameworks. These frameworks were then subjected to a sol-gel process to create a silica replica, which serves as a scaffold for further material deposition. In the LPI process, they exposed these silicated DNA nanostructures to metal salt solutions, resulting in the adsorption of metal ions onto the silica framework. Subsequent thermal annealing helped in forming a uniform metal coating, preserving the underlying DNA lattice structure. This method proved effective for incorporating elements like copper, platinum, and indium, among others, into the silica frameworks. VPI, adapted from atomic layer deposition techniques, was used to deposit metal oxides like AlOx and ZnOx onto the silica framework. The process involved exposing the silica replicas to vapor-phase organometallic precursors under specific conditions, ensuring deep penetration and uniform coating of the materials. This technique was particularly useful in maintaining the integrity of the 3D architecture and enabling the coating of larger, more complex structures.
To further expand the material versatility, the authors combined LPI and VPI methods. This approach allowed them to fabricate composite frameworks, such as platinum on aluminum-doped zinc oxide, showcasing the potential for creating multi-functional nanostructures. The results demonstrated that DNA-programmable assembly can be effectively used to create diverse 3D inorganic frameworks with nanoscale precision. This method opens up new avenues in fabricating nanostructures with tailor-made mechanical, optical, electronic, and catalytic properties. The ability to control composition and architecture at such scales has profound implications for a wide array of applications, including advanced sensing, catalysis, and photonic devices. The integration of DNA nanotechnology with traditional and novel material fabrication techniques represents a significant leap in nanofabrication. The team approach not only overcomes the limitations of current methods but also introduces a level of precision and versatility previously unattainable. This work is a step toward realizing the full potential of 3D nanoarchitectures and paves the way for novel applications that leverage the unique properties of these materials.
Michelson A, Subramanian A, Kisslinger K, Tiwale N, Xiang S, Shen E, Kahn JS, Nykypanchuk D, Yan H, Nam CY, Gang O. Three-dimensional nanoscale metal, metal oxide, and semiconductor frameworks through DNA-programmable assembly and templating. Sci Adv. 2024 Jan 12;10(2):eadl0604. doi: 10.1126/sciadv.adl0604.