NP Assemblies Research Articles

Magnetite Nanoparticle Assemblies and Their Biological Applications: A Review.

Magnetite nanoparticles (Fe3O4 NPs) have garnered significant attention over the past twenty years, primarily due to their superparamagnetic properties. These properties allow the NPs to respond to external magnetic fields, making them particularly useful in various technological applications. One of the most fascinating aspects of Fe3O4 NPs is their ability to self-assemble into complex structures. Research over this period has focused heavily on how these nanoparticles can be organized into a variety of superstructures, classified by their dimensionality-namely one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) configurations. Despite a wealth of studies, the literature lacks a systematic review that synthesizes these findings. This review aims to fill that gap by providing a thorough overview of the recent progress made in the fabrication and organization of Fe3O4 NP assemblies via a bottom-up self-assembly approach. This methodology enables the controlled construction of assemblies at the nanoscale, which can lead to distinctive functionalities compared to their individual counterparts. Furthermore, the review explores the diverse applications stemming from these nanoparticle assemblies, particularly emphasizing their contributions to important areas such as imaging, drug delivery, and the diagnosis and treatment of cancer.

Crystallization‐driven Nanoparticle Crystalsomes

AbstractNanoparticle (NP) assembly has been extensively studied, and a library of NP superstructures has been synthesized. These intricate structures show unique collective optical, electronic, and magnetic properties. In this work, we report a bottom‐up approach for fabricating spherical gold nanoparticle (AuNP) assemblies that mimic colloidosomes. Co‐crystallization of lipoic acid‐end‐functionalized poly(ethylene oxide) (PEO) and AuNPs in solution via a self‐seeding method led to the formation of hollow spherical NP assemblies named nanoparticle crystalsomes (NPCs). Due to the spherical shape, the translational symmetry of PEO crystals is broken in NPCs, which can be attributed to the competition between NP close packing and polymer crystallization. This was confirmed by tuning the NPC morphology via varying the self‐seeding temperature, crystallization temperature, and PEO molecular weight. We envisage that this strategy paves the way to attaining exquisite morphological control of NP assemblies with broken translational symmetry.

Probing the Mechanism of Targeted Delivery of Molecular Surfactants Loaded into Nanoparticles after Their Assembly at Oil–Water Interfaces

A targeted and controlled delivery of molecular surfactants at oil-water interfaces using the directed assembly of nanoparticles, NPs, is reported. The mechanism of NP assembly at the interface and the release of molecular surfactants is followed by laser scanning confocal microscopy and surface force spectroscopy. The assembly of positively charged polystyrene NPs at the oil-water interface was facilitated by the introduction of carboxylic acid groups in the oil phase (e.g., by adding 1 wt % stearic acid to hexadecane to produce a model oil). The presence of positively charged NPs consistently lowers the stiffness of the water-oil interface. The effect is lessened, when the NPs are present in a solution of NaCl or deionized water at pH 2, consistent with a less dense monolayer of NPs at the interface in the last two systems. In addition, the NPs reduce the interfacial adhesion (i.e., the "stickiness" of the interface or, put differently, the pull-off force experienced by the atomic force microscopy (AFM) tip during retraction). After the assembly, the NPs can release a previously loaded cargo of surfactant molecules, which then facilitate the formation of a much finer oil-water emulsion. As a proof of concept, we demonstrate the release of octadecyl amine, ODA, that has been incorporated into the NPs prior to the assembly. The release of ODA causes the NPs to detach from the interface altering the interfacial properties and leads to finer oil droplets. This approach can be exploited in applications in several fields ranging from pharmaceutical and cosmetics to hydrocarbon recovery and oil-spill remediation, where a targeted and controlled release of surfactants is wanted.

Plasmonic Enhancement of Chiroptical Property in Enantiomers Using a Helical Array of Magnetoplasmonic Nanoparticles for Ultrasensitive Chiral Recognition.

Recognition of enantiomeric molecules is essential in pharmaceutical and biomedical applications. In this Article, a novel approach is introduced to monitor chiral molecules via a helical magnetic field (hB), where chiral-inactive magnetoplasmonic nanoparticles (MagPlas NPs, Ag@Fe3O4 core-shell NPs) are assembled into helical nanochain structures to be chiral-active. An in-house generator of hB-induced chiral NP assembly, that is, a plasmonic chirality enhancer (PCE), is newly fabricated to enhance the circular dichroism (CD) signals from chiral plasmonic interaction of the helical nanochain assembly with circularly polarized light, reaching a limit of detection (LOD) of 10-10 M, a 1000-fold enhancement as compared to that of conventional CD spectrometry. These enhancements were successfully observed from enantiomeric molecules, oligomers, polymers, and drugs. Computational simulation studies also proved that total chiroptical properties of helical plasmonic chains could be readily changed by modifying the chiral structure of the analytes. The proposed PCE has the potential to be used as an advanced tool for qualitative and quantitative recognition of chiral materials, enabling further application in pharmaceutical and biomedical sensing and imaging.

Self-Assembly Nanoparticles of Natural Bioactive Abietane Diterpenes.

Different approaches have been reported to enhance penetration of small drugs through physiological barriers; among them is the self-assembly drug conjugates preparation that shows to be a promising approach to improve activity and penetration, as well as to reduce side effects. In recent years, the use of drug-conjugates, usually obtained by covalent coupling of a drug with biocompatible lipid moieties to form nanoparticles, has gained considerable attention. Natural products isolated from plants have been a successful source of potential drug leads with unique structural diversity. In the present work three molecules derived from natural products were employed as lead molecules for the synthesis of self-assembled nanoparticles. The first molecule is the cytotoxic royleanone 7α-acetoxy-6β-hydroxyroyleanone (Roy, 1) that has been isolated from hairy coleus (Plectranthus hadiensis (Forssk.) Schweinf). ex Sprenger leaves in a large amount. This royleanone, its hemisynthetic derivative 7α-acetoxy-6β-hydroxy-12-benzoyloxyroyleanone (12BzRoy, 2) and 6,7-dehydroroyleanone (DHR, 3), isolated from the essential oil of thicket coleus (P. madagascariensis (Pers.) Benth.) were employed in this study. The royleanones were conjugated with squalene (sq), oleic acid (OA), and/or 1-bromododecane (BD) self-assembly inducers. Roy-OA, DHR-sq, and 12BzRoy-sq conjugates were successfully synthesized and characterized. The cytotoxic effect of DHR-sq was previously assessed on three human cell lines: NCI-H460 (IC50 74.0 ± 2.2 µM), NCI-H460/R (IC50 147.3 ± 3.7 µM), and MRC-5 (IC50 127.3 ± 7.3 µM), and in this work Roy-OA NPs was assayed against Vero-E6 cells at different concentrations (0.05, 0.1, and 0.2 mg/mL). The cytotoxicity of DHR-sq NPs was lower when compared with DHR alone in these cell lines: NCI-H460 (IC50 10.3 ± 0.5 µM), NCI-H460/R (IC50 10.6 ± 0.4 µM), and MRC-5 (IC5016.9 ± 0.5 µM). The same results were observed with Roy-OA NPs against Vero-E6 cells as was found to be less cytotoxic than Roy alone in all the concentrations tested. From the obtained DLS results, 12BzRoy-sq assemblies were not in the nano range, although Roy-OA NP assemblies show a promising size (509.33 nm), Pdl (0.249), zeta potential (−46.2 mV), and spherical morphology from SEM. In addition, these NPs had a low release of Roy at physiological pH 7.4 after 24 h. These results suggest the nano assemblies can act as prodrugs for the release of cytotoxic lead molecules.

Solar transparent radiators based on in-plane worm-like assemblies of metal nanoparticles

Windows with solar heating capacity can facilitate the indoors–outdoors thermal balance and improve the thermal energy efficiency of buildings, thus reducing the energy consumption in winter; however, their development has been hindered by the narrow light absorption and limited transparency of photothermal materials. In this study, transparent solar thermal surfaces on window glazing are constructed by the in-plane linear assembly of thermoplasmonics under a hierarchical electrostatic field. First results with gold nanoparticles (Au NPs) demonstrated that the hierarchical electrostatic field induced the random generation and chain growth of NP oligomers to yield controlled in-plane nanoassemblies. The linear morphology of these nanoassemblies enhanced the local electric field along the NP chains and caused additional plasmon absorption in the near-infrared spectral region, thereby improving the photothermal conversion effect without sacrificing the transparency. The solar thermal surface with Au NP assemblies increased the window glazing temperature by up to 9.8 °C under natural solar irradiation, while maintaining a high visible transmittance (>65%). The temperature increment was within the ballpark of the highest reported values and satisfied the standard requirements for thermal insulation of buildings in cold climates. This work extends new applications of linear nanoassemblies in solar energy harvesting and related energy conversion technologies.

Effect of structure: A new insight into nanoparticle assemblies from inanimate to animate.

Nanoparticle (NP) assemblies are among the foremost achievements of nanoscience and nanotechnology because their interparticle interactions overcome the weaknesses displayed by individual NPs. However, previous studies have considered NP assemblies as inanimate, which had led to their dynamic properties being overlooked. Animate properties, i.e., those mimicking biological properties, endow NP ensembles with unique and unexpected functionalities for practical applications. In this critical review, we highlight recent advances in our understanding of the properties of NP assemblies, particularly their animate properties. Key examples are used to illustrate critical concepts, and special emphasis is placed on animate property-dependent applications. Last, we discuss the barriers to further advances in this field.

Adsorption dynamics of polymeric nanoparticles at an air-water interface with addition of surfactants

HypothesisThe unusual observation that addition of sodium dodecylsulfate surfactant to an aqueous nanoparticle dispersion slows down the decrease of air:water interfacial tension is attributed to the combined interactions of the nanoparticle with surfactant and surfactant at the air:water interface. Such dynamics are controlled by electrostatic interactions. ExperimentsThe study of dynamics is achieved using the maximum bubble pressure measurement of surface tension from 0.1 s to 30 s. The NPs are assembled by Flash NanoPrecipitation with 5 kDa polyethylene glycol coronas, and cores of polystyrene, polydimethylsiloxane, or polycaprolactone. Anionic (sodium dodecylsulfate), cationic (cetyltrimethylammonium bromide), and non-ionic (decaethylene glycol monododecyl ether) surfactants are employed over concentration 10−4 to 10−2 mM. The zeta potentials of the NPs are measured with surfactants. Electrostatic repulsion between charged NPs and interface is calculated, as well as the adsorption energy. FindingsThis is the first report to quantitatively explain the effect of surfactants on the dynamics of NP assembly at an interface. An electrostatic energy barrier slows the adsorption kinetics for NPs when the NPs have the same charge as the interface. Increasing ionic strength of the solution reduces the electrostatic barrier. Decreasing interactions between the NP core material and the surfactant reduces the barrier. Our findings offer new insights into understanding of NP interfacial self-assembly dynamics in a complex environment.

From Chains to Monolayers: Nanoparticle Assembly Driven by Smectic Topological Defects.

In this Letter, we show how advanced hierarchical structures of topological defects in the so-called smectic oily streaks can be used to sequentially transfer their geometrical features to gold nanospheres. We use two kinds of topological defects, 1D dislocations and 2D ribbon-like topological defects. The large trapping efficiency of the smectic dislocation cores not only surpasses that of the elastically distorted zones around the cores but also surpasses the one of the 2D ribbon-like topological defect. This enables the formation of a large number of aligned NP chains within the dislocation cores that can be quasi-fully filled without any significant aggregation outside of the cores. When the NP concentration is large enough to entirely fill the dislocation cores, the LC confinement varies from 1D to 2D. We demonstrate that the 2D topological defect cores induce a confinement that leads to planar hexagonal networks of NPs. We then draw the phase diagram driven by NP concentration, associated with the sequential confinements induced by these two kinds of topological defects. Owing to the excellent large-scale order of these defect cores, not only the NP chains but also the NP hexagonal networks can be oriented along the desired direction, suggesting a possible new route for the creation of either 1D or 2D highly anisotropic NP networks. In addition, these results open rich perspectives based on the possible creation of coexisting NP assemblies of different kinds, localized in different confining areas of a same smectic film that would thus interact thanks to their proximity but also would interact via the surrounding soft matter matrix.

Design of Nanoparticle Systems by Controllable Assembly and Temporal/Spatial Regulation

AbstractNanoparticles (NPs) have been studied for several decades, and outstanding advancements have been made involving fabrication methods and various properties for many different applications. NP assemblies exhibit collective properties that are superior to the properties of individual NPs, and their assembly behavior is significantly affected by interparticle interactions and surrounding layers. The temporal/spatial regulation of NPs and the active species present in NP systems are crucial for achieving desirable performances. Here, the interparticle interactions, surrounding materials (especially ligands), and temporal and spatial regulation are the main topics discussed. The principles and classical examples of these regulation strategies are provided, and the resulting NPs regulated by these strategies exhibit remarkable properties and have great potential for various applications. Finally, the future prospects of the NPs are outlined with respect to the surface modification, temporal and spatial regulation, as well as the binary cooperative complementary principle.

Modifying the Band Gap of Semiconducting Two-Dimensional Materials by Polymer Assembly into Different Structures

Polyethylene glycol (PEG) assembled on the surface of two-dimensional tungsten disulfide (WS2) into a limited number of nanoislands (NIs), nanoshells (NSs), and granular nanoparticulates (GNPs) depending on its chain length. NI assemblies showed a nonmeasurable shift of photoluminescence (PL) and the A and B absorption peaks of WS2. This confirmed that the electronic doping by thiol is not effective. The PEG NS assembly displayed a smaller red shift of the PL and a slight decrease of the energy difference between the A and B absorption peaks of WS2. However, increasing the dielectric function on the surface of WS2 has a small influence on their optical properties. The PEG NP assembly on WS2 exhibited a significant red shift of the PL spectrum and a large decrease of the energy difference between A and B absorption peaks. Deforming the WS2 sheet by the PEG NP assembly decreased the orbital coupling and lowered the electronic direct band gap significantly. Raman bands of WS2 are shifted to a higher frequency on improving its mechanical strength after the PEG assembly.

From Atoms to Lives: The Evolution of Nanoparticle Assemblies

AbstractNanoparticle (NP) assemblies have been studied over the past several decades, and the field is advancing more quickly and reaching into more diverse fields. Reports issued from academic and industrial laboratories have driven these advances. Countless breakthroughs have been reported in widely different fields, including thermoelectronics, photoelectronics, catalysts, energy sources, and medical carriers. A “family tree” is clearly needed to accurately trace the developments in the study of NP assemblies. This review uses the unconventional approach of comparing the atomic and NP worlds to describe the development of NP research during the past several decades. The corresponding classifications, such as atoms and NPs, molecules and molecular‐type NP assemblies, crystals and crystalline‐type NP assemblies, biological organisms and analogous artificial assemblies, and biologically functional NP complex assemblies, are discussed in detail. It concludes with remarks concerning the trend from nonliving to living applications of NP assemblies.

Directing Charge Transfer in Quantum Dot Assemblies.

The optical and electronic properties of semiconductor quantum dots (QDs) make them attractive candidates for applications in photovoltaics, spintronics, photocatalysis, and optoelectronics. Understanding how to control the flow of charge in QD assemblies is essential for realizing novel applications. This Account explores some unique characteristics of charge transport in QD dyads, triads, and their assemblies. The emerging features of these assemblies that provide new opportunities to manipulate charge flow at the nanoscale are (1) cascading energy landscapes and band offsets to inhibit charge recombination, (2) electrostatic fields that direct charge flow through QD-QD and QD-conjugated polymer junctions, and (3) QD chirality and chiral imprinting that promotes vectorial electron and spin selective transport. Charge flow kinetics is determined by a combination of familiar electron transfer parameters (reaction free energy, reorganization energy, and electronic coupling), donor and acceptor electronic densities of states, and internal electric fields. Electron transfer and electronic structure theory, combined with kinetic modeling, place the measured kinetics of QD electron transfer donor-acceptor assemblies into a unified conceptual context. The experimental transfer rates measured in these systems depend upon structure and the internal electric fields that are present in the assemblies. A negatively charged donor and positively charged acceptor, for example, facilitates (inhibits) electron (hole) transfer, while an electric field of opposite orientation (reversal of charges) inhibits (promotes) electron (hole) transfer. These and other emerging rules that govern charge flow in NP assemblies provide a strategy to design the directionality and yield of interfacial charge transport. Chirality at the nanoscale can induce spin selective charge transport, providing new ways to direct charge (and spin) flow in QD assemblies. Magnetoresistance and magnetic conductive probe atomic force microscopy experiments show spin selective electron transport for chirally imprinted QD assemblies. Photoinduced electron transfer from achiral donor-QDs to chiral acceptor-QDs depends on the electron spin and chiroptical properties of the acceptor-QDs. These assemblies show transport characteristics that correlate with features of the QDs' circular dichroism spectra, presenting intriguing challenges to theory, and indicating that spectroscopic signatures may assist in the design and diagnosis of functional molecular assemblies. Theoretical and experimental studies of charge transport in well-defined QD assemblies are establishing design principles for vectorial charge transport and are also refining questions surrounding the mechanism and control of these processes. These intensified efforts are forging links between fundamental discoveries regarding mechanism and practical applications for these novel assembled nanostructures.

Design Rules for Template-Confined DNA-Mediated Nanoparticle Assembly.

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.

Controlling the assembly and spin transport of tetrathiafulvalene carboxylate coated iron oxide nanoparticles

The transport mechanism and magnetoresistance of tetrathiafulvalene-carboxylate-coated Fe3O4 nanoparticle assemblies are finely tuned using controlled ligand engineering, solvent-polarity and NP assembly patterns.

Dynamic Chiral Nanoparticle Assemblies and Specific Chiroplasmonic Analysis of Cancer Cells.

Fabricated Ag@Au core-shell nanoparticle (CS NP) assemblies exhibit pronounced and reverse chiral bisignate plasmonic signals spanning 400 to 580 nm, in comparison to Ag NP assemblies. The time-dependent chiro-optical response of assemblies that shift with shell deposition is systematically recorded. Chiral Ag@Au CS NP assemblies first achieve the special discrimination of circulating tumor cells with HER2 overexpression.

Collagen hybridizing peptide: self-assembly and denatured collagen targeting

Event Abstract Back to Event Collagen hybridizing peptide: self-assembly and denatured collagen targeting Michael Yu1, Boi Hoa San1 and Yang Li1 1 University of Utah, Bioengineering, United States Summary: Collagen, the most abundant protein in mammals, plays a crucial role in tissue development and regeneration. Since elevated activity of collagen remodeling is associated with numerous pathologic conditions (e.g. tumor, fibrosis, arthritis), ability to target unstructured collagens in diseased tissue could lead to new diagnostics and therapeutics, as well as applications in regenerative medicine. Previously, we reported the new strategy for targeting denatured collagens that is based on triple helical hybridization between collagen strands (of diseased tissues) and synthetic collagen mimetic peptide (CMP) also referred to as collagen hybridizing peptide (CHP). This hybridization results in robust collagen specific binding in vivo which allows detection of degraded collagens in diseased tissues with persistent wound healing activity (e.g. tumor, arthritis)[1],[2]. In this presentation we will describe our on going investigations into elucidating the mechanism of the hybridization as well as experiments verifying the CHP’s collagen binding capacity both in vitro and in vivo (Fig. 1). We will also discuss two new CHP-mediated self-assembling systems which are based on nanoparticles and beta-sheet forming peptides (B-CMPs). CHP conjugated nanoparticles (Fig. 2) allow controlled NP assembly as well as specific detection and removal of denatured collagens from protein mixtures. B-CHPs based on FKFE and GPO repeats assemble into highly water-soluble nanofibers and nanosheets (Fig. 3) which exhibit improved affinity to denatured collagen because of multi-ligand effects. Due to its neutral and hydrophilic nature, CHPs are inert peptides exhibiting high serum stability. It is also a structurally simple peptide that can be readily conjugated to various imaging and therapeutic modalities. The CHP offers an entirely new way to target the microenvironment of diseased tissues which may lead to new opportunity for management of pathologic conditions associated with high level of collagen degradation and remodeling. This work was supported by grants from NIAMS/NIH (R01-AR060484 and R21-AR065124) and DOD (W81XWH-12-1-0555).

Assembly of the Ebola Virus Nucleoprotein from a Chaperoned VP35 Complex.

Ebolavirus NP oligomerizes into helical filaments found at the core of the virion, encapsidates the viral RNA genome, and serves as a scaffold for additional viral proteins within the viral nucleocapsid. We identified a portion of the phosphoprotein homolog VP35 that binds with high affinity to nascent NP and regulates NP assembly and viral genome binding. Removal of the VP35 peptide leads to NP self-assembly via its N-terminal oligomerization arm. NP oligomerization likely causes a conformational change between the NP N- and C-terminal domains, facilitating RNA binding. These functional data are complemented by crystal structures of the NP°-VP35 complex at 2.4 Å resolution. The interactions between NP and VP35 illuminated by these structures are conserved among filoviruses and provide key targets for therapeutic intervention.

Tunable Photophysical Processes of Porphyrin Macrocycles on the Surface of ZnO Nanoparticles

We investigated the impact of the molecular structure of cationic porphyrins on the degree of electrostatic interactions with zinc oxide nanoparticles (ZnO NPs) using steady-state and time-resolved fluorescence and transient absorption spectroscopy. Our results demonstrate that the number of cationic pyridinium units has a crucial impact on the photophysics of the porphyrin macrocycle. Fluorescence enhancement, relative to initial free porphyrin fluorescence, was found to be tuned from 3.4 to 1.3 times higher by reducing the number of cationic substituents on the porphyrin from 4 to 2. The resulting enhancement of the intensity of the fluorescence is attributed to the decrease in the intramolecular charge transfer (ICT) character between the porphyrin cavity and its meso substituent. The novel findings reported in this work provide an understanding of the key variables involved in nanoassembly, paving the way toward optimizing the interfacial chemistry of porphyrin–ZnO NP assembly for photodynamic therapy...

Spatially confined assembly of nanoparticles.

The ability to assemble NPs into ordered structures that are expected to yield collective physical or chemical properties has afforded new and exciting opportunities in the field of nanotechnology. Among the various configurations of nanoparticle assemblies, two-dimensional (2D) NP patterns and one-dimensional (1D) NP arrays on surfaces are regarded as the ideal assembly configurations for many technological devices, for example, solar cells, magnetic memory, switching devices, and sensing devices, due to their unique transport phenomena and the cooperative properties of NPs in assemblies. To realize the potential applications of NP assemblies, especially in nanodevice-related applications, certain key issues must still be resolved, for example, ordering and alignment, manipulating and positioning in nanodevices, and multicomponent or hierarchical structures of NP assemblies for device integration. Additionally, the assembly of NPs with high precision and high levels of integration and uniformity for devices with scaled-down dimensions has become a key and challenging issue. Two-dimensional NP patterns and 1D NP arrays are obtained using traditional lithography techniques (top-down strategies) or interfacial assembly techniques (bottom-up strategies). However, a formidable challenge that persists is the controllable assembly of NPs in desired locations over large areas with high precision and high levels of integration. The difficulty of this assembly is due to the low efficiency of small features over large areas in lithography techniques or the inevitable structural defects that occur during the assembly process. The combination of self-assembly strategies with existing nanofabrication techniques could potentially provide effective and distinctive solutions for fabricating NPs with precise position control and high resolution. Furthermore, the synergistic combination of spatially mediated interactions between nanoparticles and prestructures on surfaces may play an increasingly important role in the controllable assembly of NPs. In this Account, we summarize our approaches and progress in fabricating spatially confined assemblies of NPs that allow for the positioning of NPs with high resolution and considerable throughput. The spatially selective assembly of NPs at the desired location can be achieved by various mechanisms, such as, a controlled dewetting process, electrostatically mediated assembly of particles, and confined deposition and growth of NPs. Three nanofabrication techniques used to produce prepatterns on a substrate are summarized: the Langmuir-Blodgett (LB) patterning technique, e-beam lithography (EBL), and nanoimprint lithography (NPL). The particle density, particle size, or interparticle distance in NP assemblies strongly depends on the geometric parameters of the template structure due to spatial confinement. In addition, with smart design template structures, multiplexed NPs can be assembled into a defined structure, thus demonstrating the structural and functional complexity required for highly integrated and multifunction applications.