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Noninvasive In Situ Ratiometric Imaging of Biometals Based on Self-Assembled Peptide Nanoribbon
摘要： Development of probes for accurate sensing and imaging of biometals in situ is still a growing interest owing to their crucial roles in cellular metabolism, neurotransmission, and apoptosis. Among them, Zn2+ and Cu2+ are two important cooperative biometals closely related to Alzheimer’s disease (AD). Herein, we developed a multifunctional probe based on self-assembling peptide nanoribbon for ratiometric sensing of Zn2+, Cu2+, or Zn2+ and Cu2+ simultaneously. Uniform peptide nanoribbon (AQZ@NR) was rationally designed by coassembling a Zn2+-specific ligand AQZ-modified peptide (AQZKL-7) with peptide KL-7. The nanoribbon further combined with Cu2+-sensitive near-infrared quantum dots (NIR QDs) and Alexa Fluor 633 as an inner reference molecule, which was endowed with the capability for ratiometric Zn2+ and Cu2+ imaging at the same time. The peptide-based probe exhibited good specificity to Zn2+ and Cu2+ without interference from other ions. Importantly, the nanoprobe was successfully applied for noninvasive Zn2+ and Cu2+ monitoring in both living cells and zebrafish via multicolor fluorescence imaging. This gives insights into the dynamic Zn2+ and Cu2+ distribution in an intracellular and in vivo mode, as well as understanding the neurotoxicity of high concentration of Zn2+ and Cu2+. Therefore, the self-assembled nanoprobe shows great promise in multiplexed detection of many other biometals and biomolecules, which will benefit the diagnosis and treatment of AD in clinical applications.
关键词： fluorescence imaging,biometals,ratiometric imaging,peptide nanoribbon,Cu2+,Zn2+,self-assembly,Alzheimer’s disease
更新于2025-09-23 15:21:01
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Selfa??Assembled PMMA Porous Membranes Decorated with In Situ Synthesized ZnO Nanoparticles with UVa??Tunable Wettability
摘要： This study reports a simple approach to fabricate porous poly(methyl methacrylate) (PMMA) membranes homogeneously decorated with exposed zinc oxide (ZnO) nanoparticles (NPs). This fabrication method significantly overcomes the disadvantages of both conventional foaming processes and incorporation of inorganic NPs in polymeric matrices. In particular, the porous structure is simply self-assembled by slowly evaporating a suitable solvent. The ZnO NPs are in situ formed by a thermally activated conversion of the zinc acetate precursor, previously embedded in the polymeric matrix. Scanning and transmission electron microscopy investigations show the formation of the desired self-assembled highly porous structure and ZnO NPs with branched morphology, respectively. The wetting behavior of the membranes surface is studied as a function of the ZnO content and UV irradiation, exploiting the switchable wettability of ZnO. The obtained unexpected results are then tentatively rationalized taking into account the surface chemistry and the roughness that arises from both porous structure and the different NPs dimensions and content.
关键词： porous membranes,nanocomposites,tunable wettability,self-assembly,in situ synthesis
更新于2025-09-23 15:21:01
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Xenobiotic Contamination of Water by Plastics and Pesticides Revealed Through Real-time, Ultrasensitive and Reliable Surface Enhanced Raman Scattering
摘要： Uncontrolled utilization and consequent ubiquitous percolation of carcinogenic and xenobiotic contaminants, such as plasticizers and pesticides, into ecosystem has created an immediate demand for robust analytical detection techniques to identify their presence in water. Addressing this demand, we uncover the presence of xenobiotic contaminants such as Bisphenol A (BPA), Triclosan (TC), and Dimethoate (DM) through a robust, ultrasensitive and reliable Surface Enhanced Raman Scattering (SERS) platform. Thereby, conclusive real-time evidence of degradation of polyethylene terephthalate (PET) leading to release of BPA in water is presented. Worryingly, the release of BPA occurs at ambient temperature (40 0C) and within realistic timescales (12 hours) that are regularly encountered during the handling, transport and storage of PET-based water containers. Complementary mass-spectrometric, surface-specific atomic force microscopy and surface selective X-ray Photoelectron spectroscopy confirms the nanoscale surface degradation of PET through loss of C=O and C-O surface functionalities. Such ultra-sensitive (ppm-level), spectroscopic detection is enabled by the bottom-up assemblies of metal nanoparticles (Soret Colloids, SCs) acting as SERS platform to provide high analytical enhancement factor (108) with high reliability (relative standard deviation, RSD <5%). Effective and rapid detection (30 s) of several other potential xenobiotic contaminants such as Triclosan (TC) and Dimethoate (DM) over a wide range of concentrations (10-5 to 10-1 M) has also been demonstrated. Finally, non-destructive real-time spectroscopic “sniffing” of organophosphorous pesticides from the surface of fruits is achieved, illustrating the multi-phasic versatility of this label-free, non-lithography-based SERS platform.
关键词： plastic degradation,Soret colloids,water and food contamination,real-time detection,nanoparticle assembly,surface enhanced Raman scattering,Xenobiotics
更新于2025-09-23 15:21:01
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Semitransparent Perovskite Solar Cells
摘要： Solar cells are one of the most attractive and nonpolluting energy sources. In this field, hybrid and inorganic perovskite, which is a semiconductor, has been shown to function efficiently in the solar cell. One of the unique properties of perovskite allows it to become semitransparent—not just by controlling its optical properties. In this review we provide the most updated methods and techniques to make semitransparent perovskite solar cells: (i) the use of thin perovskite film; (ii) the possibility to self-assemble the perovskite on a photoanode, providing an empty transparent area while not sacrificing the light harvesting efficiency; (iii) the use of the solvent properties to form islands of perovskite using de-wetting on the surface; and (iv) the possibilities to form a transparent contact that makes the solar cell fully semitransparent. Finally, the potential and future features of semitransparent perovskite solar cells are presented.
关键词： Transparent Contact,Dewetting,Solar Cells,Perovskite,Thin Films,Semitransparent,Self-assembly
更新于2025-09-23 15:21:01
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Cd12O12 cage cluster-assembled nanowires and band gap regulation: A first-principles investigation
摘要： Based on the first-principle calculation, the stability and electronic properties of Cd12O12 cluster-assembled nanowires and Na-doped Cd12O12 nanowire are studied. The results show that both Cd12O12 nanowire and Na-doped Cd12O12 nanowire are thermodynamically stable (at least at room temperature). The most stable Cd12O12 nanowire exhibits semiconducting properties with a direct energy gap. After doping Na atoms into the nanowire, the electronic properties of the Cd12O12-based nanowire present dramatic changes, and the system transforms from semiconducting to metallic. It can provide a theoretical guidance for the potential application of Cd12O12-based semiconductor devices.
关键词： Assembly,Band gap regulation,Na doped,Cd12O12 cage cluster,Cd12O12 nanowire
更新于2025-09-23 15:21:01
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Exploiting Wavelength Orthogonality for Successive Photoinduced Polymerization-Induced Self-Assembly and Photo-Crosslinking
摘要： We report a facile benchtop process for the synthesis of cross-linked polymeric nanoparticles by exploiting wavelength-selective photochemistry to perform orthogonal photoinduced polymerization-induced self-assembly (Photo-PISA) and photo-crosslinking processes. We first established that the water-soluble photocatalyst, zinc meso-tetra(N-methyl-4-pyridyl) porphine tetrachloride (ZnTMPyP) could activate the aqueous PET-RAFT dispersion polymerization of hydroxypropyl methacrylate (HPMA). This photo-PISA process could be conducted under low energy red light (λ max = 595 nm, 10.2 mW/cm2) and without deoxygenation due to the action of the singlet oxygen quencher, biotin (vitamin B7), which allowed for the synthesis of a range of nanoparticle morphologies (spheres, worms, and vesicles) directly in 96-well plates. To perform wavelength selective nanoparticle cross-linking, we added the photoresponsive monomer, 7-[4-(trifluoromethyl)coumarin] methacrylamide (TCMAm) as a comonomer without inhibiting the evolution of the nanoparticle morphology. Importantly, under red light, exclusive activation of the photo-PISA process occurs, with no evidence of TCMAm dimerization under these conditions. Subsequent switching to a UV source (λ max = 365 nm, 10.2 mW/cm2) resulted in rapid cross-linking of the polymer chains, allowing for retention of the nanoparticle morphology in organic solvents. This facile synthesis of cross-linked spheres, worms, and vesicles demonstrates the utility of orthogonal light-mediated chemistry for performing decoupled wavelength selective chemical processes.
关键词： photoinduced polymerization-induced self-assembly,wavelength orthogonality,polymeric nanoparticles,photo-crosslinking,PET-RAFT polymerization
更新于2025-09-23 15:21:01
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Wind load analysis of a new linear Fresnel receiver assembly design
摘要： A linear Fresnel collector includes a low-profile reflector array and a receiver assembly with one or more absorber tubes and an optional secondary reflector. This combined optical system concentrates sunlight and converts it into thermal energy. The design of a receiver assembly is critical to the performance of a linear Fresnel collector. A position deviation of a few centimeters for the receiver assembly can result in notably reduced performance, thus leading to a direct loss in revenue associated with thermal power production. Wind load is one of the most significant environmental factors that can alter the optical—and therefore thermal—performance of a solar power system due to displacements after installation. At the same time, an over-designed receiver assembly may add unnecessary construction cost to a typically high-cost-constrained system. Thus, wind load analysis is particularly important when considering optimal engineering design of a receiver assembly and its supporting structure to cost-effectively mitigate the impacts of wind. In this study, a detailed computational fluid dynamics (CFD) model is adopted to derive the wind load of a commercial linear Fresnel receiver assembly. This wind load is then used as a reference to optimize the detailed engineering design. The CFD model is first carefully developed and benchmarked within a critical regime toward turbulence. The drag force, lift force, and vortex-shedding frequencies are derived at both the operating and survival wind-speed limits for target project deployment locations. The wind load analysis results provide a valuable reference for future engineering design and prototyping.
关键词： wind load analysis,receiver assembly,linear Fresnel collector,vortex-shedding frequencies,drag force,computational fluid dynamics,lift force
更新于2025-09-23 15:21:01
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Imaging Supramolecular Morphogenesis with Confocal Laser Scanning Microscopy at Elevated Temperatures
摘要： The morphogenesis of supramolecular assemblies is a highly dynamic process that has only recently been recognized, and our understanding of this phenomenon will require imaging techniques capable of crossing scales. Shape transformations depend both on the complex energy landscapes of supramolecular systems and the kinetically controlled pathways that define their structures and functions. We report here the use of confocal laser scanning microscopy coupled with a custom-designed variable-temperature sample stage that enables in situ observation of such shape changes. The submicrometer resolution of this technique allows for real-time observation of the nanostructures in the native liquid environments in which they transform with thermal energy. We use this technique to study the temperature-dependent morphogenic behavior of peptide amphiphile nanofibers and photocatalytic chromophore amphiphile nanoribbons. The variable-temperature confocal microscopy technique demonstrated in this work can sample a large volume and provides real-time information on thermally induced morphological changes in the solution.
关键词： in situ microscopy,confocal microscopy,nanofibers,nanoribbons,supramolecular assembly
更新于2025-09-23 15:21:01
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Ag2Au50(PET)36 Nanocluster: Dimeric Assembly of Au25(PET)18 Enabled by Silver Atoms
摘要： Assembly of atomically precise metal nanoclusters is now in the research spotlight, which offers exciting opportunities to gain fundamental insights into the hierarchical assembly of nanoparticles. However, it is still extremely challenging for controllable assembly of individual nanoclusters at a molecular- or atomic-level. Herein we report the dimeric assembly of Au25(PET)18 (PET = 2-phenylethanethiol), where two Au25(PET)18 monomers are bridged together by two Ag atoms to form the Ag2Au50(PET)36 dimer. The Ag2Au50(PET)36 dimer is an exclusive mesomer, which has not been found in any other chiral metal nanoclusters belonging to the racemic category. Furthermore, the Ag2Au50(PET)36 dimer is distinct from the Au25(PET)18 monomer on the optical, electronic, and catalytic properties. This study is expected to provide a feasible strategy to precisely modulate the assembly of metal nanoclusters with controllable structures and properties.
关键词： dimer,assembly,properties,Ag2Au50(PET)36,nanocluster
更新于2025-09-23 15:21:01
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The coupled dynamics of colloidal nanoparticle spreading and self-assembly at a fluid-fluid interface
摘要： We investigated the physicochemical and transport phenomena governing the self-assembly of colloidal nanoparticles at the interface of two immiscible fluids. By combining in-situ grazing incidence small-angle X-ray scattering (GISAXS) with a temporal resolution of 200 ms and electron microscopy measurements we gained new insights into the coupled effects of solvent spreading, nanoparticle assembly and recession of the vapor-liquid interface on the morphology of the self-assembled thin films. We focus on oleate-passivated PbSe nanoparticles dispersed across an ethylene glycol subphase as a model system and demonstrate how solvent parameters such as surface tension, nanoparticle solubility, aromaticity and polarity influence the mesoscale morphology of the nanoparticle superlattice. We discovered that a nanoparticle precursor monolayer film spreads in front of the bulk solution and influences the fluid spreading across the subphase. Improved understanding of the impact of kinetic phenomena (i.e., solvent spreading and evaporation) on superlattice morphology is important to describe the formation mechanism and ultimately enable assembly of high-quality superlattices with long range order.
关键词： self-assembly,interfacial phenomena,in-situ GISAXS,nanoparticle superlattice,spreading dynamics
更新于2025-09-23 15:21:01