New Technique Helps Create Resilient Synthetic Nanoparticle-Based Materials

In association with Brookhaven National Laboratory, Columbia Engineering scientists have recently reported that they have fabricated nanoparticle-based 3D materials that can tolerate high radiations, high pressures, high temperatures and vacuum.

This novel fabrication procedure leads to fully engineered and robust nanoscale frameworks that can accommodate a wide range of functional nanoparticles and can also be processed rapidly using traditional nanofabrication techniques.

These self-assembled nanoparticles-based materials are so resilient that they could fly in space. We were able to transition 3D DNA-nanoparticle architectures from a liquid state—and from being a pliable material—to solid state, where silica re-enforces DNA struts.

Oleg Gang, Professor of Chemical Engineering and Applied Physics and Materials Science

Professor Gang, who also headed the research work recently published in the Science Advances journal, added, “This new material fully maintains its original framework architecture of DNA-nanoparticle lattice, essentially creating a 3D inorganic replica. This allowed us to explore—for the first time—how these nanomaterials can battle harsh conditions, how they form, and what their properties are.”

Material characteristics tend to be different at the nanometer scale, and for a long time, scientists have been looking for ways on how to apply these small-sized materials, which measure 1,000 to 10,000 times smaller than the width of a single strand of a human hair—in different types of applications, right from designing faster chips for laptops to creating sensors for phones.

But existing fabrication methods have made it difficult to obtain 3D nano-architectures. For example, DNA nanotechnology helps create complexly arranged materials from nanoparticles via self-assembly but considering the environment-dependent and soft nature of DNA, these materials may remain stable only under a limited range of conditions.

On the contrary, the recently developed materials can now be utilized in an array of applications that require engineered structures.

Although traditional nanofabrication excels when it comes to producing planar structures, the new technique developed by professor Gang helps create 3D nanomaterials that are turning out to be crucial in many energy, optical and electronic applications.

Professor Gang, who holds a joint appointment as group leader of the Soft and Bio Nanomaterials Group at the Center for Functional Nanomaterials at the Brookhaven National Laboratory, is at the vanguard of DNA nanotechnology, which depends on folding DNA chain into required 2D and 3D nanostructures.

Such nanostructures turn out to be building blocks that can be programmed through Watson-Crick interactions to self-organize into 3D architectures.

These DNA nanostructures are designed and formed by Professor Gang’s team, combining them with nanoparticles and guiding the arrangement of targeted materials based on nanoparticles.

Now, using the latest method, the researchers can change these nanoparticle-based materials from being fragile and soft to robust and solid.

This latest analysis shows an efficient way to transform 3D DNA-nanoparticle lattices into silica replicas and, at the same time, maintain the integrity of the nanoparticle assembly and the topology of the interparticle connections by DNA struts.

Silica is known to work well because it creates a strong cast of the fundamental DNA, helps maintain the nanostructure of the parent DNA lattice, and does not impact the arrangements of nanoparticles.

The DNA in such lattices takes on the properties of silica. It becomes stable in air and can be dried and allows for 3D nanoscale analysis of the material for the first time in real space. Moreover, silica provides strength and chemical stability, it’s low-cost and can be modified as needed—it’s a very convenient material.

Aaron Michelson, PhD Student, Columbia University

Michelson works in professor Gang’s group.

To find out more about the characteristics of these nanostructures, the researchers subjected the converted nanostructures to silica DNA-nanoparticles lattices to adverse conditions—that is, high temperatures above 1000°C and high-mechanical stresses of more than 8 GPa (80 times more than at the deepest ocean site, the Mariana trench, or around 80,000 times more than the atmospheric pressure), and investigated these processes in-situ.

To determine the viability of the nanostructures for applications and additional processing steps, the investigators also exposed these structures to focused ion beams and high doses of radiation.

Our analysis of the applicability of these structures to couple with traditional nanofabrication techniques demonstrates a truly robust platform for generating resilient nanomaterials via DNA-based approaches for discovering their novel properties.

Oleg Gang, Professor of Chemical Engineering and Applied Physics and Materials Science

“This is a big step forward, as these specific properties mean that we can use our 3D nanomaterial assembly and still access the full range of conventional materials processing steps. This integration of novel and conventional nanofabrication methods is needed to achieve advances in mechanics, electronics, plasmonics, photonics, superconductivity, and energy materials,” added professor Oleg.

Associations based on professor Gang’s study have already resulted in new superconductivity and conversion of the silica to semiconductive and conductive media for additional processing.

These comprise a previous analysis published by the Nature Communications journal and one newly reported in the Nano Letters journal.

The team is also planning to alter the structure to create a wide range of materials that have highly desirable optical and mechanical properties.

Professor Gang added, “Computers have been made with silicon for over 40 years. It took four decades to push the fabrication down to about 10 nm for planar structures and devices. Now we can make and assemble nanoobjects in a test tube in a couple of hours without expensive tools. Eight billion connections on a single lattice can now be orchestrated to self-assemble through nanoscale processes that we can engineer.”

“Each connection could be a transistor, a sensor, or an optical emitter—each can be a bit of data stored. While Moore’s law is slowing, the programmability of DNA assembly approaches is there to carry us forward for solving problems in novel materials and nanomanufacturing. While this has been extremely challenging for current methods, it is enormously important for emerging technologies,” professor Gang concluded.

Journal Reference:

Majewski, P. W., et al. (2021) Resilient three-dimensional ordered architectures assembled from nanoparticles by DNA. Science Advances. doi.org/10.1126/sciadv.abf0617.