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While super‐resolution fluorescence imaging has mostly seen applications in the life sciences, an increasing number of laboratories are using these techniques to study materials. This often requires adaptation of the more commonly employed protocols that have been developed for biological systems. Here, the most representative examples of the use of super‐resolution fluorescence microscopy to study a wide range of materials, including polymers, nanofibers, carbon nanostructures, inorganic materials, and other nonbiological systems, are collected. Due to its ability to provide dynamic information, to probe below the outer surface of a material, and to gain information at the molecular level beyond ensemble averaging, super‐resolution fluorescence microscopy has the potential to provide new insights that complement those obtained by well‐established techniques in materials science.  相似文献   

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Super‐resolution light microscopy (SRM) enables imaging of biomolecules within cells with nanometer precision. Cryo‐fixation by vitrification offers optimal structure preservation of biological specimens and permits sequential cryo electron microscopy (cryoEM) on the same sample, but is rarely used for SRM due to various technical challenges and the lack of fluorophores developed for vitrified conditions. Here, a protocol to perform correlated cryoSRM and cryoEM on intact mammalian cells using fluorescent proteins and commercially available equipment is described. After cell culture and sample preparation by plunge‐freezing, cryoSRM is performed using the reversibly photoswitchable fluorescent protein rsEGFP2. Next, a super‐resolved image is reconstructed to guide cryoEM imaging to the feature of interest. Finally, the cryoSRM and cryoEM images are correlated to combine information from both imaging modalities. Using this protocol, a localization precision of 30 nm for cryoSRM is routinely achieved. No impediments to successive cryoEM imaging are detected, and the protocol is compatible with a variety of cryoEM techniques. When the optical set‐up and analysis pipeline is established, the total duration of the protocol for experienced cryoEM users is 3 days, not including cell culture.  相似文献   

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Sub-diffraction-limited imaging of fluorescent monomers on sliding microtubules in vitro by nanoscale localization sampling (NLS) is reported. NLS is based on periodic nanohole antenna arrays that create locally amplified electromagnetic hot spots through surface plasmon localization. The localized near-field hot spot temporally samples microtubular movement for enhanced spatial resolution. A fourfold improvement in spatial resolution compared to conventional wide-field microscopy is demonstrated. The resolution enhancement is achieved by imaging rhodamine-labeled microtubules that are sampled by the hot spots to provide sub-diffraction-limited images at 76 nm resolution in the direction of movement and 135 nm orthogonally. The intensity distribution produced by the NLS is measured to be broader than that of conventional imaging, which is consistent with the improvement of imaging resolution. Correlation studies between neighboring nanoantennas are also performed. This confirms the possibility of measuring microtubular transport dynamics. NLS can be useful for moving objects that have a high labeling density or for performing fluctuation spectroscopy in small volumes, and may allow \"super-resolution on demand\" by customizing nanoantenna structures for specific resolution needs.  相似文献   

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Visualization of dynamic interlinking networks which respond and adapt to the constantly changing environment would be highly beneficial in developing new composite materials and active/responsive materials. Here, optically and structurally stabilized plasmo‐bio interlinking networks (PBINs) free from photobleaching for high resolution, long term visualization are reported. Necessary for structural and optical stability, a new stability algorithm to comprehensively quantify stability and detect minute instability undetectable by traditional methods is introduced. Biocompatible plasmonic gold nanorods (Bio‐AuNRs) are synthesized for high resolution, long term imaging by utilizing bromide‐free alternatives to achieve CTA+ free. Systematic physical, chemical, and biological characterizations reveal the structural and optical stability of Bio‐AuNRs required for constructing PBIN. Lastly, with actin as a model of interlinking networks of the cytoskeleton, optically and structurally stable PBIN (100% CTA+ free, 97% crosslinking rate) in applications as active/responsive materials, are demonstrated.  相似文献   

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The combination of complementary techniques to characterize materials at the nanoscale is crucial to gain a more complete picture of their structure, a key step to design and fabricate new materials with improved properties and diverse functions. Here it is shown that correlative atomic force microscopy (AFM) and localization‐based super‐resolution microscopy is a useful tool that provides insight into the structure and emissive properties of fluorescent β‐lactoglobulin (βLG) amyloid‐like fibrils. These hybrid materials are made by functionalization of βLG with organic fluorophores and quantum dots, the latter being relevant for the production of 1D inorganic nanostructures templated by self‐assembling peptides. Simultaneous functionalization of βLG fibers by QD655 and QD525 allows for correlative AFM and two‐color super‐resolution fluorescence imaging of these hybrid materials. These experiments allow the combination of information about the topography and number of filaments that compose a fibril, as well as the emissive properties and nanoscale spatial distribution of the attached fluorophores. This study represents an important step forward in the characterization of multifunctionalized hybrid materials, a key challenge in nanoscience.  相似文献   

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Block copolymer (BCP) self‐assembly (SA) can be exploited for next‐generation lithography for the advanced nanopatterning of surfaces with versatile nanoscale features. To render BCP‐SA suitable for the creation of tailored surface patterns, a fundamental understanding of interfacial interactions is crucial. This progress report gives an overview on the interplay of BCP microscale film thickness modulation and nanoscale microphase separation during BCP‐SA. Light is shed on the role of interfacial energies in both events. Microscale processes determining the topography of BCP films, i.e., hole/island formation and dewetting into droplets, are presented. Nanoscale microphase separation into energetically favorable pattern orientations in dependency on the polymer film thickness and influenced by surface polarities are discussed critically. Finally, examples are shown in which the combination of microscale dewetting and nanoscale microphase separation are exploited to create hierarchical nanostructures from BCPs. An outlook is given presenting successful applications of both mechanisms on prepatterned surfaces in order to control position and morphology of the hierarchical nanostructures. This approach is particularly promising for the creation of advanced surface architectures.  相似文献   

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Polymerization-induced microphase separation (PIMS) is a versatile technique for producing nanostructured materials. In previous PIMS studies, the predominant approach involved employing homopolymers as macromolecular chain transfer agents (macroCTAs) to mediate the formation of nanostructured materials. In this article, the use of AB diblock copolymers as macroCTAs to design PIMS systems for 3D printing of nanostructured materials is investigated. Specifically, the influence of diblock copolymer composition and block sequence on the resulting nanostructures, and their subsequent impact on bulk properties is systematically investigated. Through careful manipulation of the A/B block ratios, the morphology and size of the nanodomains are successfully controlled. Remarkably, the sequence of A and B blocks significantly affects the microphase separation process, resulting in distinct morphologies. The effect can be attributed to changes in the interaction parameters (χAB, χBC, χAC) between the different block segments. Furthermore, the block sequence and composition exert profound influence on the thermomechanical, tensile, and swelling properties of 3D printed nanostructured materials. By leveraging this knowledge, it becomes possible to design advanced 3D printable materials with tailored properties, opening new avenues for material engineering.  相似文献   

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The self‐assembly of cylinder‐forming block copolymer (BCP) microdomains confined within chemical stripe patterns of widths incommensurate with the natural period of the copolymers, L0, is studied. It is shown that this incommensurability causes changes in both the shapes of the microdomains and their spatial period. Specifically, a transition from n to n + 1 rows of microdomains is observed when the stripe width is about n ± 1/2 L0. When the stripe's width is comparable to L0, ellipticity of microdomains can be induced with an aspect ratio up to 2.2. Free energy models are applied to describe the energetic origin of such behavior. Although our observations qualitatively resemble results in sphere‐forming BCPs confined in topographical trenches, the quantitative difference is noteworthy and technologically important for the design of nanostructures with programmable shapes.  相似文献   

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Nanosecond pulsed electric field offers novel opportunities in bionanotechnology and biomedicine enabling ultrafast physical control of membrane, and protein‐based processes for the development of novel bionanomaterials and biomedical theranostic methods. However, the mechanisms of nanosecond pulsed electric field action at the nano‐ and molecular scale are not fully understood due to lack of appropriate research tools. In order to overcome this challenge, a technological platform for the exploration of these mechanisms in live biological samples is provided here. This paper describes step by step the proposed chip platform, including the design, fabrication, installation, and testing of the chip. The developed chip is capable of delivering hundreds of volts of nanosecond electric pulses compared to conventional chips using few volts. Moreover, the chip is fully integrated into a super‐resolution microscope. Later on, the chip function is demonstrated by affecting microtubule architecture in living cells. Therefore, the chip‐based technological advancement enables the assessment of pulsed electric field effects on bionanostructures and observing their effects in real‐time. The results contribute to the chip‐based high‐frequency bioelectronics technology for modulating the function of biological matter at the nanoscale level.  相似文献   

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Nanostructured block copolymer (BCP) thin films constitute an elegant tool to generate complex periodic patterns with periodicities ranging from a few nanometers to hundreds of nanometers. Such well‐organized nanostructures are foreseen to enable next‐generation nanofabrication research with potent applications in the design of functional materials in biology, optics or microelectronics. This valuable platform is, however, limited by the geometric features attainable from diblock copolymer architectures considering the thermodynamic driving force leaning toward the formation of structures minimizing the interface between the blocks. Therefore, strategies to enrich the variety of structures obtained by BCP self‐assembly processes are gaining momentum and this progress report reviews the opportunities inherent to iterative BCP self‐assembly by considering the emerging strategies for the generation of “non‐native” morphologies.  相似文献   

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An ordered nanostructure formed by epitaxial crystallization of a semicrystalline block copolymer on a substrate has been used as a patterned template for the selective deposition of thermally evaporated gold nanoparticles, resulting in the formation of structure-guiding host nanocomposites in which the ordered distribution of the guest particles is guided by the ordering of the host nanostructured block copolymer matrix. This opens new perspectives in the field of polymeric composites related to the maximum enhancement of effective physical properties and to the numerous possible applications that arise due to the presence of long-range order in the spatial distribution of functional nanoparticles.   相似文献   

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Block copolymer (BCP) lithography is a versatile bottom‐up approach for the creation of regular nanoscale patterns on large surface areas. The pattern morphology evolving during the microphase separation of a BCP is strongly dependent on the polymer film thickness. Thus, surface wetting as well as interfacial energies between polymer and substrate determine the polymer behavior, however, the complex interplay of those effects is not yet fully understood. In this work, a model describing the film thickness dependence of BCP self‐assembly on prepatterned surfaces is proposed. Polymer dewetting on nanohole‐patterned surfaces is controlled using different prepattern dimensions, polymer amounts, and microphase‐separation temperatures. This is found to allow for a precise local film thickness modulation and thus allows to guide BCP self‐assembly into arrays of tailored hierarchical nanoarchitectures. Analytical calculations of the total surface free energies of the microphase‐separated polymer of different film thicknesses confined inside nanoholes confirm the model. The insights contribute to the understanding of fundamental processes in polymer dewetting and BCP self‐assembly and allow for the controlled creation of advanced hierarchical nanostructures on large areas for applications in optics, plasmonics, and biomedical devices.  相似文献   

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For the purpose of functionalizing III‐V semiconductor nanowires using n‐doping, Sn‐doped GaAs zincblende nanowires are produced, using the growth method of Aerotaxy. The growth conditions used are such that Ga droplets, formed on the nanowire surface, increase in number and concentrations when the Sn‐precursor concentration is increased. Droplet‐covered wires grown with varying Sn concentrations are analyzed by transmission electron microscopy and electron tomography, which together establish the positioning of the droplets to be preferentially on {?111}B facets. These facets have the same polarity as the main wire growth direction, [?1?1?1]B. This means that the generated Ga particles can form nucleation sites for possible nanowire branch growth. The concept of azimuthal mapping is introduced as a useful tool for nanowire surface visualization and evaluation. It is demonstrated here that electron tomography is useful in revealing both the surface and internal morphologies of the nanowires, opening up for applications in the analysis of more structurally complicated systems like radially asymmetrical nanowires. The analysis also gives a further understanding of the limits of the dopants which can be used for Aerotaxy nanowires.  相似文献   

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Block‐copolymer (BCP) nanospheres with hierarchical inner structure are of great interest and importance due to their possible applications in nanotechnology and biomedical engineering. Mesoporous BCP nanospheres with multilayered inner channels are considered as potential drug‐delivery systems and templates for multifunctional nanomaterials. Selective swelling is a facile pore‐making strategy for BCP materials. Herein, the selective swelling‐induced reconstruction of BCP nanospheres is reported. Two poly(styrene‐block‐2‐vinylpyridine) (PS‐b‐P2VP) samples with different compositions (PS23600b‐P2VP10400 and PS27700b‐P2VP4300) are used as model systems. The swelling reconstruction of PS‐b‐P2VP in ethanol, 1‐pyrenebutyric acid (PBA)/ethanol, or HCl/ethanol (pH = 2.61) is characterized by scanning electron microscopy and transmission electron microscopy. It is observed that the length of the swellable block in BCP is a critical factor in determining the behavior and nanostructures of mesoporous BCP nanospheres in selective swelling. Moreover, it is demonstrated that the addition of PBA modifies the swelling structure of PS23600b‐P2VP10400 through the interaction between PBA and P2VP blocks, which results in BCP nanospheres with patterned pores of controllable size. The patterned pores can be reversibly closed by annealing the mesoporous BCP nanospheres in different selective solvents. The controllable and reversible open/closed reconstruction of BCP nanospheres can be used to enclose functional nanoparticles or drugs inside the nanospheres. These mesoporous BCP nanospheres are further decorated with gold nanoparticles by UV photoreduction. The enlarged decoration area in mesoporous BCP nanospheres will enhance their activity and sensitivity as a catalyst and electrochemical sensor.  相似文献   

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