(4ch) Designing Customized Pano-Structured Materials for Improved Sustainability and Health Monitoring

In the quest to address pressing global challenges, the development of advanced material systems emerges as a critical frontier. My research program goes beyond traditional material design by pioneering pano-structured material systems—those meticulously engineered at every pertinent scale, from nano to macroscales, for unparalleled performance. Leveraging the synergistic potential of chemical synthesis, crystal engineering, and precision top-down lithography, my group aims to unlock new capabilities in sustainability and health monitoring.

Our aims are twofold: i) advancing biomolecular detection via metamaterials that harness the properties of both dielectric and plasmonic nanomaterials for more sensitive, specific, and high-throughput analyte monitoring; and ii) enhancing photocatalytic reactions for cleaner energy production and environmental remediation through the design of catalytic sites, surface area, and diffusion properties of 2D and 3D lattices. Key to our strategy is the: 1) design and synthesis of versatile material building blocks across multiple scales; 2) integration of bottom-up synthetic strategies with sophisticated top-down manufacturing processes; and 3) customization and fine-tuning of pano-structured systems for targeted applications in photocatalysis and biomolecular detection.

Together, our work represents an important step forward in chemical engineering, where the strategic design of pano-structured materials can lead to significant advancements in environmental sustainability and public health.

Graduate Research with Prof. Chad A. Mirkin at Northwestern University.

A long-standing goal of materials science is to be able to envision a desired functionality or set of material properties, employ well-defined design rules to delineate a pathway to a targeted structure, and then synthesize and characterize it. Drawing inspiration from how nature puts materials together to build intricate architectures, I apply a similar hierarchical assembly principle to synthetic particles as systems that build up from the nanoscale to the macroscale, with each level exhibiting targeted chemical, optical, and mechanical properties.

I work at the nexus of chemistry, chemical engineering, nanomaterials, and applied physics to assemble nanoparticles into colloidal crystals with functions by design, utilizing geometry-inspired design principles that span from the nanoscopic realm of individual nanoparticles to the macroscopic length scale of colloidal assemblies. Specifically, I repurpose DNA, the blueprint of life, for creating designer forms of crystalline matter. At the nanoscale, I develop a universal synthetic strategy, yielding a library of designer nanostructures, and therefore researchers now can synthesize metal nanoparticles of almost any desired shape and structure. I then employ these as building blocks to design sophisticated macroscale architectures with DNA- and shape-guided precision. For example, I address a major synthetic gap in porous crystal design over the 10-1000 nm length scale by assembling hollow nanoparticles, providing new opportunities to design the loading and transport of large guests at this size regime. The culmination of my efforts has resulted in open architectures with desired properties like broadband absorption and extraordinary mechanical strength. By pairing predictions with synthesis and blending structural design with functionality, my research not only answers fundamental scientific questions but also showcases the potential of purpose-driven crystal design. For example, while materials with a negative refractive index do not exist in nature, my team and I have identified target structures for them, paving the way to build the invisibility cloak.

Through my PhD research, I have worked in collaboration with physicists, chemists, and engineers, and I've cultivated a comprehensive skill set that includes structural design, nanoparticle, colloidal crystal, and biomaterial synthesis, and nanofabrication and characterization techniques, complemented by associated theoretical methods. Our achievements have been published in high-impact journals like Nature, Science, Science Advances, and Nature Materials, have led to three filed patents, and have been highlighted in Northwestern News, International Institute for Nanotechnology News, Department of Energy (DOE) Office of Science, National Nanotechnology Initiative, MRS Bulletin, and ScienceDaily, among others.

Postdoctoral Research with Prof. Jennifer A. Dionne at Stanford University.

As a Stanford Science Fellow at Stanford University, I have been exploring new avenues in health monitoring and photocatalysis, leveraging my expertise in chemistry, nanomaterials, and optics.

In one area, I have focused on sensitive, multiplexed, and continuous monitoring of metabolites by integrating high-quality (high-Q) dielectric metasurfaces with plasmonic reagents. Specifically, I design DNA sequences (aptamers) that undergo a structural change upon target metabolite binding. These aptamers are attached to both spherical nucleic acid (SNA) cores and high-quality silicon nanophotonic antennas. When target metabolites are present, the DNA on the metasurfaces and SNAs interact with them. This interaction effectively localizes the analytes and SNAs on the dielectric metasurfaces and creates localized hotspots, leading to a significant, detectable resonance shift, and a visible color change of the metasurfaces. We demonstrate the detection of clinically relevant concentrations of cortisol, adenosine, oestradiol, and dopamine. Our method establishes a quantitative correlation between the concentration of target molecules and the observed resonance shifts. Moreover, the dense array of resonators, combined with the application of microfluidic techniques and photochemistry, allows for the simultaneous and continuous detection of thousands of sensors targeting various metabolites. Our system, which includes modular resonator arrays and SNA structures, can be adapted for detecting a variety of molecules, including other metabolites, proteins, microRNAs, and ions, to improve individual health management.

Separately, I also focus on imaging and controlling the photochemistry of plasmonic frameworks across various scales: from individual nanoparticles to larger crystal structures, and from the atomic to the reactor level. My research trajectory encompasses: (i) Synthesizing open architecture photocatalysts with tunable optical properties and catalytic surfaces; (ii) Understanding the reaction mechanism under illumination, therefore enabling the reverse design of catalyst parameters that favor the desired transformation; and (iii) Applying the profound atomic-level insights to craft efficient reactor-scale synthesis strategies. This will not only deepen our understanding of reaction mechanisms but also improve next-generation hollow nanomaterial-based catalysts.

Teaching Interests:

With interdisciplinary training, I am prepared and excited to teach a range of classes. As a Chemical and Biological Engineering graduate student, I have been a teaching assistant for various courses such as Mass Transfer, Introduction to Polymers, and Bionanotechnology, and I earned a perfect student rating of 6/6 in all categories measured in teaching quality feedback reports. Additionally, I mentored two graduate students and one high school student during my thesis studies. I have witnessed their academic and personal growth, and consistently received positive feedback; two of my mentees co-authored publications with me — and these metrics do not capture the joy of building strong advising relationships.

I am enthusiastic to teach both core and elective courses, and my teaching program will ideally be centered on upper-level undergraduate and graduate courses, including Thermodynamics, Heat and Mass Transfer, Chemical Kinetics, Biochemical Engineering, Bionanotechnology, Polymers, and Biomaterials. I am also interested in developing an interactive course to discuss the latest approaches in nanoscience and nanotechnology. My goal is to inspire and educate the next generation of engineers and scientists through an inclusive learning environment.

Selected Awards:

• Stanford Science Fellowship, Stanford University (2024-)
• Distinguished Graduate Researcher Award, Northwestern University, Chemical Engineering (2023)
• MIT Chemical Engineering Rising Stars, Massachusetts Institute of Technology (2023)
• Ryan Fellowship, International Institute for Nanotechnology (2020-2023)
• Outstanding Research Award, International Institute for Nanotechnology (2022)
• MRS Graduate Student Award, Materials Research Society (2022)
• SPIE Optics and Photonics Education Scholarship, The International Society for Optics and Photonics (2022)
• Ludo Frevel Crystallography Scholarship, The International Centre for Diffraction Data (2022)
• Fellowship in Leadership, Center for Leadership, Northwestern University (2021)

Selected Publications:

• Li, Y., Zhou, W., Tanriover. I., Hadibrata,W., Partridge, B.E., Lin, H., Hu, X., Lee, B., Liu, J., Dravid, V. P., Aydin, K., and Mirkin, C. A., Open Channel Metal Particle Superlattices, Nature, 2022, 611, 695.
• Li, Y., Lin, H., Zhou, W., Sun, L., Samanta, D., and Mirkin, C. A., Corner-, Edge-, and Facet-Controlled Growth of Nanocrystals. Science Advances, 2021, 7, eabf1410.
• Zhou, W.*, Li, Y.*, Je, K., Vo, T., Lin, H., Partridge, B.E., Huang, Z., Glotzer, S., and Mirkin, C. A., Space-Tiled Colloidal Crystals from DNA-Forced Shape-Complementary Polyhedra Pairing, Science, 2024, 383, 312.
• Li, Y., Jin, H., Zhou, W., Wang, Z., Lin, Z., Mirkin, C.A., and Espinosa, H.D., Ultrastrong Colloidal Crystal Metamaterials Engineered with DNA, Science Advances, 2023, 9, eadj8103.