- 标题
- 摘要
- 关键词
- 实验方案
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Enzyme-free “on-off-on” photoelectrochemical biosensor based on cascaded quadratic amplification strategy for miRNA 141 detection
摘要： MicroRNAs (miRNAs) assay is of great significance for early diagnosis of diseases, so an enzyme-free “on-off-on” PEC biosensor has been developed for sensitive miRNA 141 determination. Manganese-doped cadmium sulfide coupled with zinc sulfide quantum dots (Mn:CdS@ZnS QDs) and manganese porphyrin (MnPP) have been used as photoelectric material and photosensitizer, respectively. And a high photocurrent of approximately 70.0 μA has been obtained. Cascaded quadratic amplification strategy has been applied in the system. Mn:CdS@ZnS QDs was characterized by transmission electron microscopy (TEM), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDX). Photoelectrochemical and electrochemical technologies were used to monitor the fabrication process of the biosensor. The sensing platform exhibits recommendable stability and good selectivity, miRNA 141 can be accurately quantified with a linear range of 1.00 × 10-14 to 1.00 × 10-8 mol·L-1 and the detection limit of 3.30 fmol·L-1. This method provides promising potential to explore sensitive detection models for various biological molecules.
关键词： Hybridization chain reaction,Catalytic hairpin assembly,Manganese-doped cadmium sulfide coupled with zinc sulfide quantum dots,MiRNA 141,Photoelectrochemistry,On-off-on
更新于2025-11-14 17:03:37
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Facile Interface Self-Assembly of Gold Nanoparticles as Surface-Enhanced Raman Scattering Substrate for Monitoring the Reduction of p-Nitrophenol
摘要： A facile interface self-assembly method was proposed to fabricate the gold monolayer film without any specific molecular cross-linkers. The film was served as a surface-enhanced Raman scattering substrate, which exhibited high enhancement and reproducibility to the 1 × 10-9 M rhodamine 6G aqueous solution. Based on the substrate, the in situ and real-time monitoring for the reduction of p-nitrophenol to p-aminophenol was demonstrated successfully.
关键词： Interfaces,Surface-enhanced Raman scattering,Self-assembly,Nanoparticles
更新于2025-11-14 17:03:37
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Tuneable Emission of Polyhedral Oligomeric Silsesquioxane‐ Based Nanostructures Self‐Assembled in the Presence of Europium(III) Ions: Reversible trans‐to‐cis Isomerization
摘要： Hybrids nanostructures with switchable and reversible “blue-red-green” emission were efficiently synthesized. The Polyhedral Oligomeric Silsesquioxane (POSS) behaves as a directional nano-cage for the terpyridine-based organic ligands allowing an easy complexation of Europium (III) cations. The complexes were characterized via UV-Vis and fluorescence spectroscopies and the stoichiometry was also confirmed via 1H NMR investigation. The octafunctionalized nano-cages allow forming novel self-assembled 3D architectures in presence of the lanthanide cation displaying a red-emission of particular intensity especially in solid state. The presence of an alkenyl group bridging the inorganic core to the organic moiety was employed to tune the emission properties via trans-cis isomerization of the double bond. In the case of O-POSS nanocages this isomerization was monitored also in presence of Eu(III) cations and was accompanied by an evident modification of the colour which passed from blue (trans-O-POSS) to red (Eu@trans-O-POSS) and finally to green (cis-O-POSS) as consequence of the release of the metal cations. This behaviour, together with the easy dispersion of the dry powder and the possibility of coating it as a film in presence of small amount of solvent, makes the emitting solid promising for applications in materials science.
关键词： europium,luminescence,silsesquioxanes,isomerization,self-assembly
更新于2025-11-14 15:32:45
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Directed Nanoscale Self-assembly of Natural Photosystems on Nitrogen-doped Carbon Nanotubes for Solar Energy Harvesting
摘要： Natural photosystems (PSs) have received much attention as a biological solar energy harvester because of their high quantum efficiency for energy transfer. However, the PSs hybridized with solid electrodes exhibit low light-harvesting efficiencies because of poor interface properties and random orientations of PSs, all of which interfere with efficient charge extraction and transfer. Herein, we report the linker-free, oriented self-assembly of natural PSs with nitrogen-doped carbon nanotubes (NCNTs) via electrostatic interaction. Protonated nitrogen-doped sites on the NCNTs facilitate spontaneous immobilization of the negatively charged stroma side of PSs, which provides a favorable orientation for electron transfer without electrically insulating polymer linkers. The resulting PS/NCNT hybrids exhibit a photocurrent density of 1.25 ± 0.08 μA cm-2, which is much higher than that of PS/CNT hybrids stabilized with polyethylenimine (0.60 ± 0.01 μA cm-2) and sodium dodecyl sulfate (0.14 ± 0.01 μA cm-2), respectively. This work emphasizes the importance of the linker-free assembly of PSs into well-oriented hybrid structures to construct an efficient light-harvesting electrode.
关键词： Light-harvesting,Electrostatic interaction,Photosystems,Nitrogen-doped carbon nanotubes,Self-assembly
更新于2025-11-14 15:29:11
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Self-Assembled Ordered Three-Phase Au-BaTiO <sub/>3</sub> -ZnO Vertically Aligned Nanocomposites Achieved by a Templating Method
摘要： Complex multiphase nanocomposite designs present enormous opportunities for developing next-generation integrated photonic and electronic devices. Here, a unique three-phase nanostructure combining a ferroelectric BaTiO3, a wide-bandgap semiconductor of ZnO, and a plasmonic metal of Au toward multifunctionalities is demonstrated. By a novel two-step templated growth, a highly ordered Au–BaTiO3–ZnO nanocomposite in a unique “nanoman”-like form, i.e., self-assembled ZnO nanopillars and Au nanopillars in a BaTiO3 matrix, is realized, and is very different from the random three-phase ones with randomly arranged Au nanoparticles and ZnO nanopillars in the BaTiO3 matrix. The ordered three-phase “nanoman”-like structure provides unique functionalities such as obvious hyperbolic dispersion in the visible and near-infrared regime enabled by the highly anisotropic nanostructures compared to other random structures. Such a self-assembled and ordered three-phase nanocomposite is obtained through a combination of vapor–liquid–solid (VLS) and two-phase epitaxy growth mechanisms. The study opens up new possibilities in the design, growth, and application of multiphase structures and provides a new approach to engineer the ordering of complex nanocomposite systems with unprecedented control over electron–light–matter interactions at the nanoscale.
关键词： vertically aligned nanocomposites,plasmonics,epitaxial thin films,metamaterials,three-phase nanocomposites,self-assembly
更新于2025-10-22 19:40:53
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A Facile Film-Nanoctahedron Assembly Route to Plasmonic Metamaterial Absorbers at Visible Frequencies
摘要： Plasmonic metamaterial absorbers (MAs) with broadband and near-perfect absorption properties in the visible region were successfully fabricated via a facile film-colloidal nanoparticle (NP) assembly method. In this approach, colloidal octahedral Au NPs were employed as the surface meta-atoms of MAs, while the nanoscale-thick SiO2 and Al films were used as the dielectric spacer and reflector respectively. It is worth noting that the Au nanoctahedron were randomly assembled onto the Al-SiO2 films, and no effort was made to precisely control their spatial arrangements. The optical characterization showed that the as-prepared MAs exhibited broadband high absorption (average absorptivity above 85%) within the whole visible spectrum for a broad range of incident angles (0°–60°). In particular, two polarization-independent near-perfect absorption peaks (absorptance above 99%) were recorded near 540 nm and 727 nm respectively. Moreover, the absorption properties of the MAs can be effectively controlled and tailored by varying the geometry (the thickness of the dielectric spacer and the surface coverages of the Au nanoctahedron). Electromagnetic simulations further demonstrated that enhanced Mie resonances and strong plasmonic coupling effects were critical for the designed MAs. This work here may provide an efficient and alternative route for the design of scalable visible light absorbers for applications such as solar cells, photothermalvoltaics, and biochemical sensors.
关键词： metamaterial absorbers,broadband and near-perfect absorption,aperiodic nanostructures,optical impedance matching,self-assembly
更新于2025-10-22 19:40:53
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Self-Patterned CsPbBr3 Nanocrystals for High-Performance Optoelectronics
摘要： All-inorganic lead halide perovskites are promising materials for many optoelectronic applications. However, two issues that arise during device fabrication hinder their practical use, namely inadequate continuity of coated inorganic perovskite films across large areas and inability to integrate these films with traditional photolithography due to poor adhesion to wafers. Herein, for the first time, to address these issues, we show a room-temperature synthesis process employed to produce CsPbBr3 perovskite nanocrystals with two-dimensional (2D) nanosheet features. Due to the unique properties of these 2D nanocrystals, including the 'self-assembly' characteristic, and 'double solvent evaporation inducing self-patterning' strategy are used to generate high-quality patterned thin films in selected areas automatically after-drop-casting, enabling fabrication of high-performance devices without using complex and expensive fabrication processing techniques. The films are free from micro-cracks. In a proof-of-concept experiment, photodetector arrays are used to demonstrate the superior properties of such films. We provide evidence of both high responsivity (9.04 A/W) and high stability across large areas. The photodetectors fabricated on flexible substrate exhibit outstanding photo-response stability. Advanced optical and structural studies reveal the possible mechanism. Our simple and cost-effective method paves the way for the next-generation nanotechnology based on high-performance, cost-effective optoelectronic devices.
关键词： photodetector,Self-assembly,self-patterning,two-dimensional nanosheet,perovskite
更新于2025-09-23 15:23:52
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Photooxidase-mimicking nanovesicles with superior photocatalytic activity and stability based on amphiphilic amino acid and phthalocyanine co-assembly
摘要： Enzyme mimics have broad applications in catalysis and can assist elucidation of the catalytic mechanism of natural enzymes. However, challenges arise from the design of catalytic sites, the selection of host molecules and their integration into active three-dimensional structures. Herein, we develop a mimic photooxidase by synergetic molecular self-assembly. 9-Fluorenylmethyloxycarbonyl-L-histidine in combination with phthalocyanine shows efficient co-assembly into nanovesicles with flexibly tunable particle size and membrane thickness. The obtained nanovesicles are capable of reactive oxygen-mediated photosensitive oxidation with improved efficiency and stability. This work highlights the co-assembly of simple building blocks into a supramolecular photocatalyst, which might give insight into possible evolutionary paths of photocatalytic membraneous systems and will allow the facile transfer into photosensitive nanoreactors or artificial organelles.
关键词： self-assembly,photooxidase,amino acids,nanovesicles,phthalocyanines
更新于2025-09-23 15:23:52
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Oligo(ethylene glycol)/alkyl-modified chromophore assemblies for photon upconversion in water
摘要： Molecular self-assembly is a powerful means to construct nanoscale materials with advanced photophysical properties. Although the protection of the photo-excited states from oxygen quenching is a critical issue, it still has been in an early phase of development. In this work, we demonstrate that a simple and typical molecular design for aqueous supramolecular assembly, modification of chromophoric unit with hydrophilic oligo(ethylene glycol) chains and hydrophobic alkyl chains, is effective to avoid oxygen quenching of triplet-triplet annihilation-based photon upconversion (TTA-UC). While a TTA-UC emission is completely quenched when the donor and acceptor are molecularly dispersed in chloroform, their aqueous co-assemblies exhibit a clear upconverted emission in air-saturated water even under extremely low chromophore concentrations down to 40 μM. The generalization of this nano-encapsulation approach offers new functions and applications using oxygen-sensitive species for supramolecular chemistry.
关键词： photon upconversion,photochemistry,oxygen quenching,self-assembly,triplet-triplet annihilation
更新于2025-09-23 15:23:52
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X-Shaped Polycyclic Aromatic Hydrocarbons: Optical Properties and Tunable Assembly Ability
摘要： Although a number of synthetic methodologies have been developed to prepare stable polycyclic aromatic hydrocarbons (PAHs), much less research has been devoted to functionalize the peripheral of molecules to tune the self-assembly ability or introduce functional groups without altering their photophysical properties. Herein, we report twisted “X” shaped molecules prepared through annulation of hexacene with benzoanthracene on the zigzag edge, and an investigation of their photophysical properties and self-assembly properties. The shape-complementary “X” shaped molecules prefer to dimerize, while the π-extension would lead to one dimensional π-stacking. Our findings gave some insights into the design of stable PAHs without disturbing the electronic structures.
关键词： Photophysical properties,Self-assembly,Polycyclic aromatic hydrocarbons,Dimerize
更新于2025-09-23 15:23:52