Organic Nanostructures Research Articles

Metal organic framework-based nanostructure materials: applications for non-lithium ion battery electrodes

Non-lithium ion (e.g., Al3+, Ca2+, K+, Mg2+, Na+, and Zn2+) batteries have emerged as a promising platform for next-generation energy storage systems.

Co-assembly of a multicomponent network of nanofiber-wrapped nanotubes.

Strategies to create organized multicomponent nanostructures composed of discrete, self-sorted domains are important for developing materials that mimic the complexity and multifunctionality found in biological systems. These structures can be challenging to achieve due to the required balance of molecular self-recognition and supramolecular attraction needed between the components. Herein, we report a strategy to construct a two-component nanostructure via a hierarchical assembly process whereby two monomeric building blocks undergo self-sorting assembly at the molecular level followed by a supramolecular association to form a nanofiber-wrapped nanotube. The two molecules self-sorted into respective nanofiber and nanotube assemblies, yet assembly of the nanofibers in the presence of the nanotube template allowed for directed integration into a hierarchical multilayer structure via electrostatic interactions. The fiber-wrapped nanotube co-assembly was characterized using transmission electron microscopy (TEM), atomic force microscopy (AFM) and Förster resonance energy transfer (FRET) between the components. Strategies to co-assemble multicomponent nanostructures composed of discrete, spatially sorted domains with controllable higher level interactions will be critical for the development of novel, functionally competent nanomaterials.

Metal/nitrogen co-doped hollow carbon nanorods derived from self-assembly organic nanostructure for wide bandwidth electromagnetic wave absorption

Converting carbonaceous material into heteroatom-doped hollow nanomaterial is a promise route to realize lightweight and high-performance electromagnetic wave absorption (EMA). In this work, a series of metal/nitrogen co-doped hollow carbon nanorods (M-NHCRs, M represent as Fe, Co, Ni) were successfully fabricated via a facile self-assembly template strategy, which refers to self-assembling of 9,10-dibromoanthracene (DBA), surficial modification with polydopamine (PDA) and metal ions, and controlled pyrolysis. Among these M-NHCRs, Co-NHCR exhibits remarkable EMA performance, where the optimal reflection loss (RL) reaches −58.6 dB at a loading ratio of 5 wt%. Moreover, the effective absorption bandwidth (EAB) gets to 7.65 GHz. It is considered that the high-performance EMA should be attributed to the unique hollow structure, excellent conductance loss and improved polarization relaxation. This research not only provides a new idea for the design of lightweight electromagnetic absorbents with broadband efficient absorption, but also broadens the way of synthesizing hollow nanomaterials. • Hollow carbon nanorod was constructed by thermally removable self-assembly template. • Doping by trace of metal obviously enhances electromagnetic absorption performance. • Effective absorption bandwidth (EAB) gets to 7.65 GHz at low loading ratio.

Donor–acceptor organic nanostructure based on conjugated polymer for improving visible-light-driven photocatalytic activity towards degradation of dye in aqueous medium

Hybrid donor–acceptor nanostructures based on P3HT with improved light harvesting properties were employed for organic dye degradation.

A subtle functional design of hollow CoP@MoS2 hetero-nanoframes with excellent hydrogen evolution performance

As the star material among nonprecious electrocatalysts, molybdenum disulfide (MoS2) has received much attention. However, the catalytic inertness of the basal plane, low conductivity of its steady state (2H phase), and the agglomeration of lamellar structures have seriously hindered its catalytic performance. It is very essential to design and modulate the morphology and phase of MoS2 to improve the above issues by synergistic regulation of electrical structure and defect engineering. Herein, MoS2 was delicately composited on CoP nanoframe derived from a typical metal–organic frame nanostructure (ZIF-67), forming the hollow CoP@MoS2 hetero-nanoframe. This exquisite externally layered and internally hollow CoP@MoS2 electrocatalyst demonstrated excellent catalytic performance for the hydrogen evolution reaction, with a low overpotential of 119 mV at 10 mA cm−2, a small Tafel slope of 49 mV dec−1, a large electric double-layer capacitance of 10.28 mF cm−2, and prominent long-term stability. The remarkable catalytic performance of hollow CoP@MoS2 hetero-nanoframe can be attributed to the unique architecture of the hetero-nanostructures, appropriate component ratios, strong interaction between CoP and MoS2, and large-scale defects and disorder. First-principles density-functional theory calculations can prove the above arguments adequately, the hydrogen adsorption free energy of CoP@MoS2 is close to zero.

Assessment of the optical and electrical properties of light-emitting diodes containing carbon-based nanostructures and plasmonic nanoparticles: a review.

Light-emitting diodes (LED) are widely employed in display applications and lighting systems. Further research on LED that incorporates carbon nanostructures and metal nanoparticles exhibiting surface plasmon resonance has demonstrated a significant improvement in device performance. These devices offer lower turn-on voltages, higher external quantum efficiencies, and luminance. De facto, plasmonic nanoparticles, such as Au and Ag have boosted the luminance of red, green, and blue emissions. When combined with carbon nanostructures they additionally offer new possibilities towards lightweight and flexible devices with better thermal management. This review surveys the diverse possibilities to combine various inorganic, organic, and carbon nanostructures along with plasmonic nanoparticles. Such combinations would allow an enhancement in the overall properties of LED.

Au nanoparticles decorated ZnO/ZnFe2O4 composite SERS-active substrate for melamine detection

Surface-enhanced Raman scattering (SERS) based on plasmonic metal nanoparticles and semiconductors has been used as performance-enhancing structures for sensing trace chemicals. We have selected a case of oxide functional oxide organic nanostructure between ZnFe2O4 and ZnO, denoted as ZZF. By decorating such nanostructure with AuNPs, to identify R6G in varying concentrations (10−6 M − 10−12 M), an enhancement factor of 1.6 × 108 was observed. The material was used for the identification of melamine in the concentration range of 0.39 μM–7.92 μM. This high-performance nanocomposite provides improved melamine sensitivity towards SERS and the limit of detection as low as 0.39 μM. The Au-ZZF SERS substrate can yield a SERS enhancement factor of 1.37 × 107. The experimental performance demonstrates that excellent SERS enhancement is due to electrons movement within ZZF and Au nanoparticles. Owing to its easy and effective synthesis methodology, this sensitive and specific SERS substrate is a promising technique to detect trace chemicals. We further study the best energetically favorable orientation of melamine molecules over the substrate leading to the SERS activity using density functional theoretical study.

A NOVEL ROUTE FOR THE FORMATION OF GAS SENSORS

The rapid development of conductive polymers shows great potential in temperature chemical gas detection as their electrical conductivity is often changed upon spotlight to oxidative or reductive gas molecules at room temperature. However, the relatively low conductivity and high affinity toward volatile organic compounds and water molecules always exhibit low sensitivity, poor stability and gas selectivity, which hinder their practical gas sensor applications. In addition, inorganic sensitive materials show totally different advantages in gas sensors like high sensitivity, fast response to low concentration analytes, high area and versatile surface chemistry, which could harmonize the conducting polymers in terms of the sensing individuality. It seems to be a good option to combine inorganic sensitive materials with polymers for gas detection for the synergistic effects which has attracted extensive interests in gas sensing applications. In this appraisal the recapitulation of recent development in polymer inorganic nanocomposites-based gas sensors. The roles of inorganic nanomaterials in improving the gas sensing performances of conducting polymers are introduced and therefore the progress of conducting polymer inorganic nanocomposites including metal oxides, metal, carbon (carbon nanotube, graphene) and ternary composites are obtainable. Finally, conclusion and perspective within the field of gas sensors incorporating conducting polymer inorganic nanocomposites are summarized. Keywords: Gas sensor, conducting polymer, polymer-inorganic nanocomposites; conducting organic polymers nanostructure, synergistic effect, polypyrrole (PPY), polyaniline (PANI).

Ubiquitous organic molecule-based free-standing nanowires with ultra-high aspect ratios

The critical dimension of semiconductor devices is approaching the single-nm regime, and a variety of practical devices of this scale are targeted for production. Planar structures of nano-devices are still the center of fabrication techniques, which limit further integration of devices into a chip. Extension into 3D space is a promising strategy for future; however, the surface interaction in 3D nanospace make it hard to integrate nanostructures with ultrahigh aspect ratios. Here we report a unique technique using high-energy charged particles to produce free-standing 1D organic nanostructures with high aspect ratios over 100 and controlled number density. Along the straight trajectory of particles penetrating the films of various sublimable organic molecules, 1D nanowires were formed with approximately 10~15 nm thickness and controlled length. An all-dry process was developed to isolate the nanowires, and planar or coaxial heterojunction structures were built into the nanowires. Electrical and structural functions of the developed standing nanowire arrays were investigated, demonstrating the potential of the present ultrathin organic nanowire systems.

Bio-inspired inclined nanohair arrays with tunable mechanical properties for effective directional condensed microdroplets self-jumping

Anisotropic surfaces comprised of organized asymmetric nanostructures have provided the basis for diverse functions due to their direction-dependent properties, such as directional liquid self-transportation by condensed microdroplet self-jumping (CMDSJ). However, it is still a challenge to facile fabricate the organized asymmetric nanostructures to realize the directional CMDSJ. On the other hand, mechanical properties of the nanosurface is a key factor influencing the CMDSJ, which is always ignored. Here, inspired by the inclined tapered setae on the leg of water striders, inclined nanohair arrays which form a ratchet structure is facilely fabricated at low cost and large area by nanoimprinting followed by directional template removing. Microdroplets with diameter larger than 10 µm show directional CMDSJ on this surface whose mechanical properties (hardness and modulus) are strengthened by depositing silica nanoparticles. This is because the moving droplet suffers less lateral force which prevents the movement of the droplet as moving along the inclined direction of the nanohair than that moving along the opposite direction. The simulation result is corresponding to the experiment well. This work shows a facile way to obtain anisotropic structure with directional CMDSJ property and has a deep insight into how mechanical properties of the nanostructure influence the CMDSJ.

Recent advances in nano-engineered approaches used for enzyme immobilization with enhanced activity

Enzyme immobilization has been achieved on various functional nanostructures to increase their shelf-life, enhancement of productivity, stability, reusability and develop a biocatalyst or biosensor. Current review is ascribing the recent advances in the art of immobilization with great efficiency by adopting logistic and sensible nano-engineering approaches i.e nanoparticles, nanoliposomes, nanotubes, fibers and membranes, beads, sol–gel, metal–organic frameworks, DNA nanostructures, nanowires, nanostars, nanocystals, nanoflowers and nanocages. The activity of various immobilized enzyme i.e. lipase, glucose oxidase, laccase, alcohol dehydrogenase and many more on these newer nanostructures are discussed here demonstrating interaction of biomacromolecules with these nanostructures. Taking Glucose oxidase as an example, it’s immobilization on metallic nanoparticles, nano-liposomes, gold nanostars, carbon nanotubes, hydrogel and hybrid nanoparticles to develop a nano-biocatalyst/biosensor has also been discussed. This review will provide a great insight in the selection of nanostructure with different morphologies and composition so that it can be extended for the multi-enzyme immobilization with multi-functionality, stability and reusability for industrial and clinical translation.

Chiral 2D-Perovskite Nanowires for Stokes Photodetectors.

Structural engineering in multiple scales permits the integration of exotic properties into a single material, which boosts the development of ultracompact multifunctional devices. Layered perovskites are capable of cross-linking efficient carrier transport originating from few-layer perovskite frameworks with extended functionalities contributed by designable bulky organic cations and nanostructures, thus providing a platform for multiscale material engineering. Herein, high-performance Stokes-parameter photodetectors for arbitrary polarized light detection are realized on the basis of solution-processed chiral-perovskite nanowire arrays. The chiral ammonium cations intercalated between the perovskite layers are responsive to circularly polarized light with a maximum anisotropy factor of 0.15, while the strictly aligned nanowires with the anisotropic dielectric function result in a large polarized ratio of 1.6 to linearly polarized light. Single crystallinity and pure crystallographic orientation permit efficient in-plane carrier transport along the nanowires, yielding a responsivity of 47.1 A W-1 and a detectivity of 1.24 × 1013 Jones. By synergy of linear- and circular-polarization response with high optoelectronic performance for providing sufficient photocurrent contrasts, Stokes-parameter photodetection is demonstrated on these nanowires. Our Stokes-parameter photodetectors with a small footprint and high performances present promising applications toward polarization imaging.

On-Surface Synthesis of Giant Conjugated Macrocycles.

We have achieved an on-surface synthesis of giant conjugated macrocycles having a diameter of ≈7 nm and consisting of up to 30 subunits. The synthesis started with a debrominative coupling of the molecular precursors on a hot Ag(111) surface, leading to the formation of arched oligomeric chains and macrocycles. These products were revealed by scanning tunneling microscopy in combination with density functional theory to be covalent oligomers. These intermediates also display C-Ag organometallic bonds between parallel molecular subunits due to site-selective debromination and the asymmetric molecular conformation. Subsequent cyclodehydrogenation at higher temperatures steered the final conjugation of the macrocycles. Our findings provide a novel design strategy toward π-conjugated macrocycles and open up new opportunities for the precise synthesis of organic nanostructures.

On‐Surface Synthesis of Giant Conjugated Macrocycles

AbstractWe have achieved an on‐surface synthesis of giant conjugated macrocycles having a diameter of ≈7 nm and consisting of up to 30 subunits. The synthesis started with a debrominative coupling of the molecular precursors on a hot Ag(111) surface, leading to the formation of arched oligomeric chains and macrocycles. These products were revealed by scanning tunneling microscopy in combination with density functional theory to be covalent oligomers. These intermediates also display C–Ag organometallic bonds between parallel molecular subunits due to site‐selective debromination and the asymmetric molecular conformation. Subsequent cyclodehydrogenation at higher temperatures steered the final conjugation of the macrocycles. Our findings provide a novel design strategy toward π‐conjugated macrocycles and open up new opportunities for the precise synthesis of organic nanostructures.

Two-Dimensional Metal–Organic Framework Nanostructures Based on 4,4′-Sulfonyldibenzoate for Photocatalytic Degradation of Organic Dyes

Two-Dimensional Metal–Organic Framework Nanostructures Based on 4,4′-Sulfonyldibenzoate for Photocatalytic Degradation of Organic Dyes

Controllable Synthesis and Effects of Porphyrin Copper Nanostructures on Photoelectric Properties

A variety of organic semiconductor nanostructures have been already reported for photoelectric applications; however, there are a few systematic studies on the dependence of their photocurrent on n...

Bimetallic Ce/Zr UiO-66 Metal–Organic Framework Nanostructures as Peptidase and Oxidase Nanozymes

The catalytic activity of metal–organic frameworks (MOFs) toward peptides and proteins provides an attractive route for the development of nanozymes for applications in biotechnology and proteomics...

Feather Gene Expression Elucidates the Developmental Basis of Plumage Iridescence in African Starlings.

Iridescence is widespread in the living world, occurring in organisms as diverse as bacteria, plants, and animals. Yet, compared to pigment-based forms of coloration, we know surprisingly little about the developmental and molecular bases of the structural colors that give rise to iridescence. Birds display a rich diversity of iridescent structural colors that are produced in feathers by the arrangement of melanin-containing organelles called melanosomes into nanoscale configurations, but how these often unusually shaped melanosomes form, or how they are arranged into highly organized nanostructures, remains largely unknown. Here, we use functional genomics to explore the developmental basis of iridescent plumage using superb starlings (Lamprotornis superbus), which produce both iridescent blue and non-iridescent red feathers. Through morphological and chemical analyses, we confirm that hollow, flattened melanosomes in iridescent feathers are eumelanin-based, whereas melanosomes in non-iridescent feathers are solid and amorphous, suggesting that high pheomelanin content underlies red coloration. Intriguingly, the nanoscale arrangement of melanosomes within the barbules was surprisingly similar between feather types. After creating a new genome assembly, we use transcriptomics to show that non-iridescent feather development is associated with genes related to pigmentation, metabolism, and mitochondrial function, suggesting non-iridescent feathers are more energetically expensive to produce than iridescent feathers. However, iridescent feather development is associated with genes related to structural and cellular organization, suggesting that, while nanostructures themselves may passively assemble, barbules and melanosomes may require active organization to give them their shape. Together, our analyses suggest that iridescent feathers form through a combination of passive self-assembly and active processes.

Rational Design of a Dual-Layered Metal-Organic Framework Nanostructure for Enhancing the Cell Imaging of Molecular Beacons.

As the most popular nucleic acid probe, molecular beacons (MBs) can selectively light up endogenous RNA targets without specific treatment. However, the poor cell permeability and unsatisfied intracellular stability of MBs significantly restricted their detection performance. Herein, we report the encapsulation of MB within a dual-layered metal-organic framework nanostructure UiO66-ZIF8 for enhanced cell imaging. UiO66-NH2 nanoparticles were synthesized as the template for MB loading, and the ZIF-8 shell was further coated on the surface of UiO66-MB to ensure its stability and lysosomal escape effect. Taking multidrug-resistant (MDR1) mRNA as a model target, MBs loaded within UiO66-ZIF8 showed an improved lysosomal escape effect compared with MB absorbed on UiO66-NH2. Therefore, efficient and accurate intracellular MDR1 mRNA imaging was realized with UiO66-MB-ZIF8. This work presented a new method for the rational regulation of the intracellular fate of MOF-based nanoprobes and will facilitate the further development of hierarchical MOF nanoprobes for analytical applications.

Tri-metallic Co-Ni-Cu based metal organic framework nanostructures for the detection of an anticancer drug nilutamide

This work reports a biosensor based on tri-metallic organic framework (MOF) for the determination of an anticancer therapeutic agent, nilutamide (NLM). The tri-metallic Co-Ni-Cu-MOF and the single metal MOFs Co-MOF, Ni-MOF and Cu-MOF were grown onto nickel foam (NF) substrate by a solvothermal method. The crystal, chemical structure, morphology and surface area of the MOFs were studied by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) analysis. The electrochemical sensing of NLM by the Co-Ni-Cu-MOF/NF and the single metal MOFs grown onto NF were studied by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). The CV of the Co-Ni-Cu-MOF/NF shows a redox couple between -0.4 V and 0.3 V in phosphate buffer solution at pH 7.0. The Co-Ni-Cu-MOF/NF sensor shows a strong electrocatalytic activity towards the redox reaction of NLM with a broad concentration range from 0.5–70 μM and 70–900 μM with high sensitivity of 10.712 μA μM−1 cm-2 and a low limit of detection of 0.48 ± 0.02 nM. These results confirm that the tri-metallic MOF possesses high selectivity and sensitivity for the determination of NLM from human serum specimen and pharmaceutical tablet dosage forms.