Publications
Shukun Yin, Dickson R Yao, Inho Kim, Wenjie Zhou, Wenzheng Heng, Wenjian Li, Songsong Tang, Xiaotian Ma, Yadong Xu, Gwangmook Kim, Hong Han, Kexin Fan, Chiara Daraio, Wei Gao, Proceedings of the National Academy of Sciences of U.S.A. 2026, 123(17), e2532988123.
Abstract
Mobile robots are increasingly deployed in diverse settings, ranging from logistic and household applications to ecological monitoring and operation in extreme environments. In these contexts, robots must traverse diverse terrains, yet most existing designs rely on fixed morphologies that limit efficiency across domains. Biomimetic solutions emulate natural forms but cannot fully exploit engineered mechanisms, while active adaptive architectures typically require complex electronics and incur substantial energy costs. Inspired by amphibians and reptiles, we developed AdaptBot, an untethered adaptive soft robot that integrates rigid machinery with responsive soft materials to achieve passive reconfiguration for amphibious locomotion. AdaptBot employs a single bioinspired photothermal artificial muscle (PAM) to power multiple gaits by light, a fast and large swelling hydrogel (FLASH) to drive passive fin deployment in water, and a ratcheting transmission to convert reciprocating PAM motion into forward locomotion. These elements enable multimodal performance—including rolling, load-carrying, climbing, and paddling—under wireless control across terrestrial, aquatic, and transitional environments. Remarkably, following fin deployment, AdaptBot’s swimming speed increased by 780%, demonstrating that passive adaptation is an effective strategy to enhance locomotor efficiency in robots operating in unstructured and dynamic environments.
Wenjie Zhou. Foundations of Crystallography, 2026, 82 (1).
Abstract
Knowing which crystal networks are “maximally symmetric” gives scientists a clean map of the most fundamental building blocks for designing new materials. These highly symmetric patterns already underlie many porous crystals and can guide the creation of future materials for gas storage, catalysis and mechanical metamaterials. By translating the mathematics of these networks into plain language, the commentary helps make this powerful but under-appreciated framework more visible to chemists, materials scientists and engineers.
Songyun Gu, Chenkai Mao, Anna Guell Izard, Sarvesh Sadana, Dongping Terrel-Perez, Magi Mettry-Yassa, Wonjin Choi, Wenjie Zhou, Hujie Yan, Ziran Zhou, Travis Massey, Alex Abelson, You Zhou, Sijia Huang, Chiara Daraio, Thejaswi Umanath Tumkur, Jonathan A Fan, Xiaoxing Xia. Nature, 2025, 648, 591–599.
Abstract
The growing demand for advanced materials, miniaturized devices and integrated microsystems calls for the reliable fabrication of complex, multiscale, three-dimensional (3D) architectures, a need increasingly addressed through light-based and laser-based processes. However, owing to the field-of-view (FOV) limitations of conventional imaging optics, existing 3D laser nanofabrication techniques face fundamental challenges in throughput, proximity error and stitching defects on the path to scaling. Here we present a scalable 3D nanofabrication platform that uses a metalens-generated focal spot array to parallelize two-photon lithography (TPL) beyond centimetre-scale write field areas. Metalenses are ideally suited for producing submicron-scale focal spots for high-throughput nanolithography, as they uniquely feature large numerical apertures (NAs), immersion media compatibility and large-scale manufacturability. We experimentally demonstrate a printing system that uses a 12-cm2 metalens array to produce more than 120,000 cooperative focal spots, corresponding to a throughput exceeding 108 voxels s−1. By programmatically patterning the focal spot array using a spatial light modulator (SLM), an adaptive parallel printing strategy is developed for precise greyscale linewidth modulation and choreographed printing of semiperiodic and fully aperiodic 3D geometries. We demonstrate parallel printing of replicated microstructures (>50 M microparticles per day), centimetre-scale 3D architectures with feature sizes down to 113 nm, and photonic and mechanical metamaterials. This work demonstrates the potential of 3D nanolithography towards wafer-scale production, showing how TPL could be used at scale for applications in microelectronics, biomedicine, quantum technology and high-energy laser targets.
Chad A Mirkin, Sarah Hurst Petrosko, …, Wenjie Zhou, Shengshuang Zhu, Wei Zhu. ACS Nano, 2025, 19, 31933–31968.
Abstract
Significant advances in science and engineering often emerge at the intersections of disciplines. Nanoscience and nanotechnology are inherently interdisciplinary, uniting researchers from chemistry, physics, biology, medicine, materials science, and engineering. This convergence has fostered novel ways of thinking and enabled the development of materials, tools, and technologies that have transformed both basic and applied research, as well as how we address critical societal challenges. In this Nano Focus, we pose and explore 33 questions whose answers could profoundly impact fields such as energy, electronics, the environment, optics, and medicine. These questions highlight the need for deeper foundational understanding, improved tools and techniques, and innovative applications─each with significant societal relevance. Together, they represent a global call-to-action for the scientific community.
Hujie Yan, Zhiqiang Meng, Ziran Zhou, Wenjie Zhou, Chiara Daraio, Physical Review Letters, 2025, 135, 088201.
Abstract
Interlocked and polycatenated material systems, consisting of discrete, nonconvex particles linked to their nearest neighbors, such as chainmail fabrics, have been shown to undergo a jamming transition that increases their rigidity under boundary compression. This rigidity transition is associated with an increase in contact number between particles. In architected materials, rigidity is described by theories such as the Maxwell criterion. In this Letter, we propose a rigidity theory for a type of interlocked material system: the torus knot tessellation. Torus knot tessellations are structured fabrics composed of particles shaped as torus knots. In these fabrics, we theoretically demonstrate that in-plane rigidity is governed by a modified Maxwell criterion, while out-of-plane rigidity is governed by a crease line criterion. These theories provide a framework for the design of rigidity of these fabrics.
Yuanwei Li, Wenjie Zhou, Yuan Zhou, Ho Fung Cheng, Byeongdu Lee, Xiaobing Hu, Eric W Roth, Vinayak P Dravid, Sharon C Glotzer, Chad A Mirkin, Science Advances, 2025, 11, eadu4919.
Abstract
Colloidal cocrystallization enables the formation of multicomponent materials with unique physicochemical properties, yet the role of nanoparticle (NP) shape and specific ligand interactions to cocrystallize anisotropic and isotropic NPs, with order and correlated disorder, remains underexplored. Here, geometry-inspired strategies along with programmable DNA interactions are combined to achieve structural control of colloidal cocrystal assemblies. Coassembling polyhedral and spherical NPs with complementary DNA yields two classes of cocrystals: one where both components order, and another where polyhedral NPs form a periodic lattice, while spherical NPs remain disordered but spatially correlated with polyhedral edges and corners. The size ratio of the building blocks can be used to control the ordering of spherical NPs—smaller octahedral-to-sphere size ratios favor fully ordered cocrystals. Molecular dynamics simulations further elucidate the role of NP shapes and dimensions in the structural outcome of the cocrystal. This work provides a framework for deliberately targeting and accessing crystals with exotic multicomponent structures.
Wenjie Zhou, Sujeeka Nadarajah, Liuchi Li, Anna Guell Izard, Hujie Yan, Aashutosh K Prachet, Payal Patel, Xiaoxing Xia, Chiara Daraio, Science, 2025, 387, 269 [Cover Article].
Abstract
Architected materials derive their properties from the geometric arrangement of their internal structural elements. Their designs rely on continuous networks of members to control the global mechanical behavior of the bulk. In this study, we introduce a class of materials that consist of discrete concatenated rings or cage particles interlocked in three-dimensional networks, forming polycatenated architected materials (PAMs). We propose a general design framework that translates arbitrary crystalline networks into particle concatenations and geometries. In response to small external loads, PAMs behave like non-Newtonian fluids, showing both shear-thinning and shear-thickening responses, which can be controlled by their catenation topologies. At larger strains, PAMs behave like lattices and foams, with a nonlinear stress-strain relation. At microscale, we demonstrate that PAMs can change their shapes in response to applied electrostatic charges. The distinctive properties of PAMs pave the path for developing stimuli-responsive materials, energy-absorbing systems, and morphing architectures.
Ye Zhang, David D Xu, Ibrahim Tanriover, Wenjie Zhou, Yuanwei Li, Rafael López-Arteaga, Koray Aydin, Chad A Mirkin, Nature Photonics, 2025, 19, 20–27.
Abstract
Atomic and molecular structure inversion symmetry breaking in naturally occurring crystals dictate their physical properties including nonlinear optical (NLO) effects, piezo- or ferroelectricity, and non-reciprocal charge transport behaviour. With metamaterials composed of nanoscale building blocks (that is, meta-atoms), the spatial inversion symmetry violation on planar surfaces leads to spin-controlled photonics as well as NLO metasurfaces. Synthetically, low-symmetry 3D metacrystals can be synthesized, but NLO behaviour has not been identified so far (for example, harmonic generations). Herein we show how DNA-mediated assembly of octahedron-shaped plasmonic gold nanocrystals can be used to design and deliberately synthesize non-centrosymmetric and centrosymmetric colloidal crystals. Importantly, while the centrosymmetric structures do not exhibit substantial second-harmonic generation, the non-centrosymmetric crystals do—a consequence of the asymmetric distribution of localized electric fields in plasmonic hotspots. Moreover, this non-centrosymmetric NLO metacrystal represents a 3D NLO metamaterial being developed via a bottom-up approach, exhibiting a maximum second-harmonic generation conversion efficiency of 10−9 to surpass the efficiencies observed in the majority of plasmonic 2D metasurfaces. Finally, the DNA-loading density on the particle building blocks can be used to toggle between the centrosymmetric and non-centrosymmetric phases.
Athanasios A Tountas, Anselm Dreher, Wenjie Zhou, Abhinav Mohan, Nazir P Kherani, Geoffrey A Ozin, Mohini M Sain, Npj Computational Materials, 2024, 10, 239.
Abstract
In this work, we set out to elucidate the light-harvesting properties of various random and ordered photocatalyst supports (PSs) with different macropore sizes. To accomplish this, we propose two studies of increasing relevance, enabled by computed tomography (CT) reconstructions and ray-tracing COMSOL Multiphysics simulations: (a) a 360-degree light release study approximating a PS situated within a compound parabolic concentrator (CPC) or cylindrical LED reactor with open ends; and (b) the same system as before but with closed ends. The ordered geometry is of interest, as it can be 3D printed at scale with a tailored morphology and porosity, and it can potentially be refined using machine learning models to optimize its light-harvesting properties. As will be shown, the local volumetric light absorption (LVLA) data suggests that an ordered PS with a more open pore interior and a smaller pore exterior would begin to approach the more isophotonic light-harvesting properties of random PSs.
Wenjie Zhou, Yuanwei Li, Benjamin E Partridge, Chad A Mirkin, Chemical Reviews, 2024, 124, 11063-11107.
Abstract
Programming the organization of discrete building blocks into periodic and quasi-periodic arrays is challenging. Methods for organizing materials are particularly important at the nanoscale, where the time required for organization processes is practically manageable in experiments, and the resulting structures are of interest for applications spanning catalysis, optics, and plasmonics. While the assembly of isotropic nanoscale objects has been extensively studied and described by empirical design rules, recent synthetic advances have allowed anisotropy to be programmed into macroscopic assemblies made from nanoscale building blocks, opening new opportunities to engineer periodic materials and even quasicrystals with unnatural properties. In this review, we define guidelines for leveraging anisotropy of individual building blocks to direct the organization of nanoscale matter. First, the nature and spatial distribution of local interactions are considered and three design rules that guide particle organization are derived. Subsequently, recent examples from the literature are examined in the context of these design rules. Within the discussion of each rule, we delineate the examples according to the dimensionality (0D–3D) of the building blocks. Finally, we use geometric considerations to propose a general inverse design-based construction strategy that will enable the engineering of colloidal crystals with unprecedented structural control.
Zhiwei Li, Yein Lim, Ibrahim Tanriover, Wenjie Zhou, Yuanwei Li, Ye Zhang, Koray Aydin, Sharon C Glotzer, Chad A Mirkin, Science Advances, 2024, 10(29), eadp3756.
Abstract
Colloidal crystal engineering with DNA allows one to design diverse superlattices with tunable lattice symmetry, composition, and spacing. Most of these structures follow the complementary contact model, maximizing DNA hybridization on building blocks and producing relatively close-packed lattices. Here, low-symmetry kagome superlattices are assembled from DNA-modified gold bipyramids that can engage only in partial DNA surface matching. The bipyramid dimensions and DNA length can be engineered for two different superlattices with rhombohedral unit cells, including one composed of a periodic stacking of kagome lattices. Enabled by the partial facet alignment, the kagome lattices exhibit lattice distortion, bipyramid twisting, and planar chirality. When conjugated with Cy-5 dyes, the kagome lattices serve as cavities with high-density optical states and large Purcell factors along lateral directions, leading to strong dipole radiation along the z axis and facet-dependent light emission. Such complex optical properties make these materials attractive for lasers, displays, and quantum sensing constructs.
Geoffrey Ozin, Todd Siler, Chenxi Qian, Wenjie Zhou, Matter, 2024, 7(3), 718-722.
Abstract
A career materials chemist and a group of art-science colleagues explore the colorful tapestry of curiosity-creativity-imagination-intuition-wonderment elements inherent in the process of materials discovery in the past and today by human intelligence and in the future by artificial intelligence.
Wenjie Zhou, Yein Lim, Haixin Lin, Sangmin Lee, Yuanwei Li, Ziyin Huang, Jingshan S Du, Byeongdu Lee, Shunzhi Wang, Ana Sánchez-Iglesias, Marek Grzelczak, Luis M Liz-Marzán, Sharon C Glotzer, Chad A Mirkin, Nature Materials, 2024, 23, 424-428.
Abstract
In principle, designing and synthesizing almost any class of colloidal crystal is possible. Nonetheless, the deliberate and rational formation of colloidal quasicrystals has been difficult to achieve. Here we describe the assembly of colloidal quasicrystals by exploiting the geometry of nanoscale decahedra and the programmable bonding characteristics of DNA immobilized on their facets. This process is enthalpy-driven, works over a range of particle sizes and DNA lengths, and is made possible by the energetic preference of the system to maximize DNA duplex formation and favour facet alignment, generating local five- and six-coordinated motifs. This class of axial structures is defined by a square–triangle tiling with rhombus defects and successive on-average quasiperiodic layers exhibiting stacking disorder which provides the entropy necessary for thermodynamic stability. Taken together, these results establish an engineering milestone in the deliberate design of programmable matter.
Wenjie Zhou, Yuanwei Li, Kwanghwi Je, Thi Vo, Haixin Lin, Benjamin E Partridge, Ziyin Huang, Sharon C Glotzer, Chad A Mirkin, Science, 2024, 383, 312-319.
Abstract
Generating space-filling arrangements of most discrete polyhedra nanostructures of the same shape is not possible. However, if the appropriate individual building blocks are selected (e.g., cubes), or multiple shapes of the appropriate dimensions are matched (e.g., octahedra and tetrahedra) and their pairing interactions are subsequently forced, space-filled architectures may be possible. With flexible molecular ligands (polyethylene glycol–modified DNA), the shape of a polyhedral nanoparticle can be deliberately altered and used to realize geometries that favor space tessellation. In this work, 10 new colloidal crystals were synthesized from DNA-modified nanocrystal building blocks that differed in shapes and sizes, designed to form space-filling architectures with micron-scale dimensions. The insights and capabilities provided by this new strategy substantially expand the scope of colloidal crystals possible and provide an expanded tool kit for researchers interested in designing metamaterials.
Yuanwei Li, Hanxun Jin, Wenjie Zhou, Zhe Wang, Zhaowen Lin, Chad A Mirkin, Horacio D Espinosa, Science Advances, 2023, 9(39), eadj8103.
Abstract
Lattice-based constructs, often made by additive manufacturing, are attractive for many applications. Typically, such constructs are made from microscale or larger elements; however, smaller nanoscale components can lead to more unusual properties, including greater strength, lighter weight, and unprecedented resiliencies. Here, solid and hollow nanoparticles (nanoframes and nanocages; frame size: ~15 nanometers) were assembled into colloidal crystals using DNA, and their mechanical strengths were studied. Nanosolid, nanocage, and nanoframe lattices with identical crystal symmetries exhibit markedly different specific stiffnesses and strengths. Unexpectedly, the nanoframe lattice is approximately six times stronger than the nanosolid lattice. Nanomechanical experiments, electron microscopy, and finite element analysis show that this property results from the buckling, densification, and size-dependent strain hardening of nanoframe lattices. Last, these unusual open architectures show that lattices with structural elements as small as 15 nanometers can retain a high degree of strength, and as such, they represent target components for making and exploring a variety of miniaturized devices.
Chaojian Chen, Millicent Lin, Carolin Wahl, Yuanwei Li, Wenjie Zhou, Zhe Wang, Ye Zhang, Chad A Mirkin, Journal of the American Chemical Society, 2023, 145, 7974-7982.
Abstract
We report a general nanopatterning strategy that takes advantage of the dynamic coordination bonds between polyphenols and metal ions (e.g., Fe3+ and Cu2+) to create structures on surfaces with a range of properties. With this methodology, under acidic conditions, 29 metal–phenolic complex-based precursors composed of different polyphenols and metal ions are patterned using scanning probe and large-area cantilever free nanolithography techniques, resulting in a library of deposited metal–phenolic nanopatterns. Significantly, post-treatment of the patterns under basic conditions (i.e., ammonia vapor) triggers a change in coordination state and results in the in situ generation of more stable networks firmly attached to the underlying substrates. The methodology provides control over feature size, shape, and composition, almost regardless of substrate (e.g., Si, Au, and silicon nitride). Under reducing conditions (i.e., H2) at elevated temperatures (180–600 °C), the patterned features have been used as nanoreactors to synthesize individual metal nanoparticles. At room temperature, the ammonia-treated features can reduce Ag+ to form metal nanostructures and be modified with peptides, proteins, and thiolated DNA via Michael addition and/or Schiff base reaction. The generality of this technique should make it useful for a wide variety of researchers interested in modifying surfaces for catalytic, chemical and biological sensing, and template-directed assembly purposes.
Yuanwei Li †, Wenjie Zhou †, Ibrahim Tanriover †, Wisnu Hadibrata, Benjamin E Partridge, Haixin Lin, Xiaobing Hu, Byeongdu Lee, Jianfang Liu, Vinayak P Dravid, Koray Aydin, Chad A Mirkin, Nature, 2022, 611, 695-701.
Abstract
Although tremendous advances have been made in preparing porous crystals from molecular precursors, there are no general ways of designing and making topologically diversified porous colloidal crystals over the 10–1,000 nm length scale. Control over porosity in this size range would enable the tailoring of molecular absorption and storage, separation, chemical sensing, catalytic and optical properties of such materials. Here, a universal approach for synthesizing metallic open-channel superlattices with pores of 10 to 1,000 nm from DNA-modified hollow colloidal nanoparticles (NPs) is reported. By tuning hollow NP geometry and DNA design, one can adjust crystal pore geometry (pore size and shape) and channel topology (the way in which pores are interconnected). The assembly of hollow NPs is driven by edge-to-edge rather than face-to-face DNA–DNA interactions. Two new design rules describing this assembly regime emerge from these studies and are then used to synthesize 12 open-channel superlattices with control over crystal symmetry, channel geometry and topology. The open channels can be selectively occupied by guests of the appropriate size and that are modified with complementary DNA (for example, Au NPs).
Yuanwei Li, Ibrahim Tanriover, Wenjie Zhou, Wisnu Hadibrata, Sina Abedini Dereshgi, Devleena Samanta, Koray Aydin, Chad A Mirkin, Small, 2022, 18, 2201171.
Abstract
Broadband absorbers are useful ultraviolet protection, energy harvesting, sensing, and thermal imaging. The thinner these structures are, the more device-relevant they become. However, it is difficult to synthesize ultrathin absorbers in a scalable and straightforward manner. A general and straightforward synthetic strategy for preparing ultrathin, broadband metasurface absorbers that do not rely on cumbersome lithographic steps is reported. These materials are prepared through the surface-assembly of plasmonic octahedral nanoframes (NFs) into large-area ordered monolayers via drop-casting with subsequent air-drying at room temperature. This strategy is used to produce three types of ultrathin broadband absorbers with thicknesses of ≈200 nm and different lattice symmetries (loose hexagonal, twisted hexagonal, dense hexagonal), all of which exhibit efficient light absorption (≈90%) across wavelengths ranging from 400–800 nm. Their broadband absorption is attributed to the hollow morphologies of the NFs, the incorporation of a high-loss material (i.e., Pt), and the strong field enhancement resulting from surface assembly. The broadband absorption is found to be polarization-independent and maintained for a wide range of incidence angles (±45°). The ability to design and fabricate broadband metasurface absorbers using this high-throughput surface-based assembly strategy is a significant step toward the large-scale, rapid manufacturing of nanophotonic structures and devices.
Devleena Samanta, Wenjie Zhou, Sasha B Ebrahimi, Sarah Hurst Petrosko, Chad A Mirkin, Advanced Materials, 2021, 2107875.
Abstract
Colloidal crystal engineering with DNA has led to significant advances in bottom-up materials synthesis and a new way of thinking about fundamental concepts in chemistry. Here, programmable atom equivalents (PAEs), comprised of nanoparticles (the “atoms”) functionalized with DNA (the “bonding elements”), are assembled through DNA hybridization into crystalline lattices. Unlike atomic systems, the “atom” (e.g., the nanoparticle shape, size, and composition) and the “bond” (e.g., the DNA length and sequence) can be tuned independently, yielding designer materials with unique catalytic, optical, and biological properties. In this review, nearly three decades of work that have contributed to the evolution of this class of programmable matter is chronicled, starting from the earliest examples based on gold-core PAEs, and then delineating how advances in synthetic capabilities, DNA design, and fundamental understanding of PAE-PAE interactions have led to new classes of functional materials that, in several cases, have no natural equivalent.
Shunzhi Wang, Sangmin Lee, Jingshan S Du, Benjamin E Partridge, Ho Fung Cheng, Wenjie Zhou, Vinayak P Dravid, Byeongdu Lee, Sharon C Glotzer, Chad A Mirkin, Nature Materials, 2022, 21, 580-587.
Abstract
Colloidal crystal engineering of complex, low-symmetry architectures is challenging when isotropic building blocks are assembled. Here we describe an approach to generating such structures based upon programmable atom equivalents (nanoparticles functionalized with many DNA strands) and mobile electron equivalents (small particles functionalized with a low number of DNA strands complementary to the programmable atom equivalents). Under appropriate conditions, the spatial distribution of the electron equivalents breaks the symmetry of isotropic programmable atom equivalents, akin to the anisotropic distribution of valence electrons or coordination sites around a metal atom, leading to a set of well-defined coordination geometries and access to three new low-symmetry crystalline phases. All three phases represent the first examples of colloidal crystals, with two of them having elemental analogues (body-centred tetragonal and high-pressure gallium), while the third (triple double-gyroid structure) has no known natural equivalent. This approach enables the creation of complex, low-symmetry colloidal crystals that might find use in various technologies.
Ho Fung Cheng, Max E Distler, Byeongdu Lee, Wenjie Zhou, Steven Weigand, Chad A Mirkin, Journal of the American Chemical Society, 2021, 143, 41, 17170-17179.
Abstract
The chemical interactions that lead to the emergence of hierarchical structures are often highly complex and difficult to program. Herein, the synthesis of a series of superlattices based upon 30 different structurally reconfigurable DNA dendrimers is reported, each of which presents a well-defined number of single-stranded oligonucleotides (i.e., sticky ends) on its surface. Such building blocks assemble with complementary DNA-functionalized gold nanoparticles (AuNPs) to yield five distinct crystal structures, depending upon choice of dendrimer and defined by phase symmetry. These DNA dendrimers can associate to form micelle-dendrimers, whereby the extent of association can be modulated based upon surfactant concentration and dendrimer length to produce a low-symmetry Ti5Ga4-type phase that has yet to be reported in the field of colloidal crystal engineering. Taken together, colloidal crystals that feature three different types of particle bonding interactions—template–dendron, dendrimer–dendrimer, and DNA–modified AuNP-dendrimer—are reported, illustrating how sequence-defined recognition and dynamic association can be combined to yield complex hierarchical materials.
Jingshan S Du, Wenjie Zhou, Sara M Rupich, Chad A Mirkin, Angewandte Chemie International Edition, 2021, 133, 6934-6939.
Abstract
The structure of multiply twinned particles (MTPs) provides an example of how specific crystallographic features dictate the geometric shape of finite-sized crystals. The formation of MTPs during colloidal synthesis can occur through at least two different pathways: 1) growth from multiply twinned seeds or 2) the stepwise formation of new twin boundaries on single-crystalline seeds (either by particle overgrowth or multiparticle attachment). By utilizing in situ transmission electron microscopy, recent studies have provided real-time evidence for both pathways. Looking forward, the knowledge of specific evolution pathways that occur under a given synthetic condition will aid in the design of robust MTP syntheses. More importantly, further studies pertaining to the structural evolution and energetics of nanoparticles are needed to provide a complete understanding of MTP formation pathways.
Yuanwei Li, Haixin Lin, Wenjie Zhou, Lin Sun, Devleena Samanta, Chad A Mirkin, Science Advances, 2021, 7, eabf1410.
Abstract
The ability to precisely control nanocrystal (NC) shape and composition is useful in many fields, including catalysis and plasmonics. Seed-mediated strategies have proven effective for preparing a wide variety of structures, but a poor understanding of how to selectively grow corners, edges, and facets has limited the development of a general strategy to control structure evolution. Here, we report a universal synthetic strategy for directing the site-specific growth of anisotropic seeds to prepare a library of designer nanostructures. This strategy leverages nucleation energy barrier profiles and the chemical potential of the growth solution to control the site-specific growth of NCs into exotic shapes and compositions. This strategy can be used to not only control where growth occurs on anisotropic seeds but also control the exposed facets of the newly grown regions. NCs of many shapes are synthesized, including over 10 here-to-fore never reported NCs and, in principle, many others are possible.
Lin Sun, Haixin Lin, Yuanwei Li, Wenjie Zhou, Jingshan S Du, Chad A Mirkin, Advanced Materials, 2020, 32, 2005316.
Abstract
Colloidal crystals have emerged as promising candidates for building optical microdevices. Techniques now exist for synthesizing them with control over their nanoscale features (e.g., particle compositions, sizes, shapes, and lattice parameters and symmetry); however, the ability to tune macroscale structural features, such as the relative positions of crystals to one another and lattice orientations, has yet to be realized. Here, inspiration is drawn from epitaxial growth strategies in atomic crystallization, and patterned substrates are prepared that, when used in conjunction with DNA-mediated nanoparticle crystallization, allow for control over individual Wulff-shaped crystal growth, location, and orientation. In addition, the approach allows exquisite control over the patterned substrate/crystal lattice mismatch, something not yet realized for any epitaxy process. This level of structural control is a significant step toward realizing complex, integrated devices with colloidal crystal components, and this approach provides a model system for further exploration in epitaxy systems.
Jingshan S Du, Donghoon Shin, Teodor K Stanev, Chiara Musumeci, Zhuang Xie, Ziyin Huang, Minliang Lai, Lin Sun, Wenjie Zhou, Nathaniel P Stern, Vinayak P Dravid, Chad A Mirkin, Science Advances, 2020, 6, eabc4959.
Abstract
Halide perovskites have exceptional optoelectronic properties, but a poor understanding of the relationship between crystal dimensions, composition, and properties limits their use in integrated devices. We report a new multiplexed cantilever-free scanning probe method for synthesizing compositionally diverse and size-controlled halide perovskite nanocrystals spanning square centimeter areas. Single-particle photoluminescence studies reveal multiple independent emission modes due to defect-defined band edges with relative intensities that depend on crystal size at a fixed composition. Smaller particles, but ones with dimensions that exceed the quantum confinement regime, exhibit blue-shifted emission due to reabsorption of higher-energy modes. Six different halide perovskites have been synthesized, including a layered Ruddlesden-Popper phase, and the method has been used to prepare functional solar cells based on single nanocrystals. The ability to pattern arrays of multicolor light-emitting nanocrystals opens avenues toward the development of optoelectronic devices, including optical displays.
Wenjie Zhou, Zizhuo Liu, Ziyin Huang, Haixin Lin, Devleena Samanta, Qing-Yuan Lin, Koray Aydin, Chad A Mirkin, Proceedings of the National Academy of Sciences of U.S.A. 2020, 117, 21052.
Abstract
Anchoring nanoscale building blocks, regardless of their shape, into specific arrangements on surfaces presents a significant challenge for the fabrication of next-generation chip-based nanophotonic devices. Current methods to prepare nanocrystal arrays lack the precision, generalizability, and postsynthetic robustness required for the fabrication of device-quality, nanocrystal-based metamaterials. To address this challenge, we have developed a synthetic strategy to precisely arrange any anisotropic colloidal nanoparticle onto a substrate using a shallow-template-assisted, DNA-mediated assembly approach. We show that anisotropic nanoparticles of virtually any shape can be anchored onto surfaces in any desired arrangement, with precise positional and orientational control. Importantly, the technique allows nanoparticles to be patterned over a large surface area, with interparticle distances as small as 4 nm, providing the opportunity to exploit light–matter interactions in an unprecedented manner. As a proof-of-concept, we have synthesized a nanocrystal-based, dynamically tunable metasurface (an anomalous reflector), demonstrating the potential of this nanoparticle-based metamaterial synthesis platform.
Shunzhi Wang, Jingshan S Du, Nicolas J Diercks, Wenjie Zhou, Eric W Roth, Vinayak P Dravid, Chad A Mirkin, Journal of the American Chemical Society, 2019, 144(51), 20443-20450.
Abstract
Colloidal crystal engineering with DNA has emerged as a powerful tool for precisely controlling the arrangement of nanoscale building blocks in three-dimensional superlattices, where nanoparticles densely modified with DNA can be viewed as “programmable atom equivalents” (PAEs). Although a wide variety of complementary DNA-modified nanoparticles, differentiated by size, shape, and composition, have been assembled into many “ionic” phases, the predictable formation of “alloy” phases remains elusive. Here, we describe the design of “colloidal crystal alloys” by combining gold PAEs of two different sizes (core diameters ranging from 5 to 40 nm) with complementary DNA-modified 2 nm gold nanoparticles (∼15 DNA strands/particle) that act as electron equivalents (EEs). Electron microscopy and small-angle X-ray scattering (SAXS) experiments reveal the formation of four classes of colloidal alloy equivalents: interstitial, substitutional, phase-separated, and intermetallic alloys. In these colloidal alloy phases, PAEs occupy lattice positions, while EEs stabilize the PAE lattice but do not occupy specific lattice sites. A set of chemical design guidelines emerge from this study, analogous to that of the Hume–Rothery rules, allowing for programmed synthesis of different alloy phases depending on PAE particle size ratio, DNA surface coverage, stoichiometric ratio, and thermal annealing pathways. Furthermore, we study the phase separation process via in situ SAXS experiments as well as ex situ electron microscopy, revealing the critical role of kinetics on the phase behavior in these systems.
Cindy Y Zheng, Edgar Palacios, Wenjie Zhou, Wisnu Hadibrata, Lin Sun, Ziyin Huang, George C Schatz, Koray Aydin, Chad A Mirkin, Advanced Materials, 2019, 31, 1904448.
Abstract
Colloidal crystal engineering with DNA on template-confined surfaces is used to prepare arrays of nanocube-based plasmonic antennas and deliberately place dyes with sub-nm precision into their hotspots, on the DNA bonds that confine the cubes to the underlying gold substrate. This combined top-down and bottom-up approach provides independent control over both the plasmonic gap and photonic lattice modes of the surface-confined particle assemblies and allows for the tuning of the interactions between the excited dyes and plasmonically active antennas. Furthermore, the gap mode of the antennas can be modified in situ by utilizing the solvent-dependent structure of the DNA bonds. This is studied by placing two dyes, with different emission wavelengths, under the nanocubes and recording their solvent-dependent emission. It is shown that dye emission not only depends upon the in-plane structure of the antennas but also the size of the gap, which is regulated with solvent. Importantly, this approach allows for the systematic understanding of the relationship between nanoscale architecture and plasmonically coupled dye emission, and points toward the use of colloidal crystal engineering with DNA to create stimuli responsive architectures, which can find use in chemical sensing and tunable light sources.
Wenjie Zhou, Qing-Yuan Lin, Jarad A Mason, Vinayak P Dravid, Chad A Mirkin, Small, 2018, 14(44), 1802742.
Abstract
Template-based strategies are becoming increasingly important for controlling the position of nanoparticle-based (NP-based) structures on surfaces for a wide variety of encoding and device fabrication strategies. Thus, there is an increasing need to understand the behavior of NPs in confined spaces. Herein, a systematic investigation of the diffusion and adsorption properties of DNA-modified NPs is presented in lithographically defined, high-aspect-ratio pores using a template-confined, DNA-mediated assembly. Leveraging the sequence-specific binding affinity of DNA, it is discovered that although NP adsorption in deep polymer pores follows a traditional Langmuir adsorption model when under thermodynamic control, such NPs kinetically follow Fick’s classical law of diffusion. Importantly, these observations allow one to establish design rules for template-confined, DNA-mediated NP assembly on substrates based on pore dimensions, NP size and shape, NP concentration, temperature, and time. As a proof-of-concept example, these design rules are used to engineer a vertical, four-layer assembly consisting of individual octahedral NPs stacked on top of one another, with in-plane positioning defined by pores generated by e-beam lithography.
Yuchan Dong, Kulbir Kaur Ghuman, Radian Popescu, Paul N Duchesne, Wenjie Zhou, Joel YY Loh, Abdinoor A Jelle, Jia Jia, Di Wang, Xiaoke Mu, Christian Kübel, Lu Wang, Le He, Mireille Ghoussoub, Qiang Wang, Thomas E Wood, Laura M Reyes, Peng Zhang, Nazir P Kherani, Chandra Veer Singh, Geoffrey A Ozin, Advanced Science, 2018, 1700732.
Abstract
Frustrated Lewis pairs (FLPs) created by sterically hindered Lewis acids and Lewis bases have shown their capacity for capturing and reacting with a variety of small molecules, including H2 and CO2, and thereby creating a new strategy for CO2 reduction. Here, the photocatalytic CO2 reduction behavior of defect-laden indium oxide (In2O3−x(OH)y) is greatly enhanced through isomorphous substitution of In3+ with Bi3+, providing fundamental insights into the catalytically active surface FLPs (i.e., InOH···In) and the experimentally observed “volcano” relationship between the CO production rate and Bi3+ substitution level. According to density functional theory calculations at the optimal Bi3+ substitution level, the 6s2 electron pair of Bi3+ hybridizes with the oxygen in the neighboring InOH Lewis base site, leading to mildly increased Lewis basicity without influencing the Lewis acidity of the nearby In Lewis acid site. Meanwhile, Bi3+ can act as an extra acid site, serving to maximize the heterolytic splitting of reactant H2, and results in a more hydridic hydride for more efficient CO2 reduction. This study demonstrates that isomorphous substitution can effectively optimize the reactivity of surface catalytic active sites in addition to influencing optoelectronic properties, affording a better understanding of the photocatalytic CO2 reduction mechanism.
Miaomiao Ye, Chenxi Qian, Wei Sun, Le He, Jia Jia, Yuchan Dong, Wenjie Zhou, Journal of Materials Chemistry C, 2016, 4, 4577-4583.
Abstract
While various forms of silicon have been widely used in the semiconductor industry and other fields, this is the first time hydride-terminated silicon particles have been employed as a reducing agent for redox active dyes. The vivid colours of the dyes can be easily decoloured within seconds to minutes by hydride-terminated silicon particles with different sizes in the nanometer to micron size range and completely recovered to their original colours after separating the silicon particles and further exposing to air. As a comparison, other traditional reducing agents such as Na2SO3 and NaBH4, as well as the silicon particles without HF etching were also employed for the reduction–reoxidation of the dye, respectively. By making use of the colour switching property of the dye, a polymer–dye composite film was shown to function as an indicator for oxygen. This film is very sensitive to oxygen and air while remaining stable in vacuum, argon, carbon dioxide and nitrogen gas atmospheres. Oxygen indicator films with different colours can also be made by incorporating different redox active dyes in the films.
