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Cancer recurrence remains a major challenge after primary tumor excision, and the inflammation of tumor-caused wounds can hinder wound healing and potentially promote tumor growth. Herein, a chiral L-phenylalanine-based (LPFEG) supramolecular hydrogel system encapsulated with polydopamine nanoparticles (PDA-NPs) has been developed in order to prevent tumor relapse after surgery and promote wound repair. PDA-NPs allow for near-infrared (NIR) light-triggered photothermal therapy, especially, it can scavenge free radicals in the surgical wound. LPFEG can mimic native extracellular matrix (ECM) structure to create a chiral microenvironment that enhances fibroblast adhesion, proliferation, and new tissue regeneration. With anticancer drug doxorubicin (DOX) loaded into the composite hydrogel, the antitumor effect is significantly enhanced by the integration of chemo-photothermal therapy both in vitro and in vivo. The PDA-based chiral supramolecular composite hydrogel as an effective postoperative adjuvant possesses promising applicable prospects in inhibiting tumor recurrence and accelerating wound healing after operation. After primary tumor excision, cancer recurrence remains a severe concern, and the inflammation induced by tumor-related wounds can delay wound healing. Herein, we designed a chiral L-phenylalanine-based (LPFEG) supramolecular hydrogel platform that was co-assembled with polydopamine nanoparticles (PDA-NPs). Among them, PDA-NPs can offer photothermal therapy and scavenge free radicals in surgical wounds. LPFEG can create a chiral microenvironment that promotes fibroblast adhesion, proliferation, and new tissue regeneration. Furthermore, with anticancer drug doxorubicin (DOX) loaded into the composite hydrogel, the antitumor effect is considerably boosted. Therefore, the PDA-based chiral supramolecular hydrogel shows high application potential as a postoperative adjuvant in preventing tumor relapse as well as accelerating wound healing after surgery. [Display omitted] [ABSTRACT FROM AUTHOR]

Modifying photocatalysts for effective NO removal has profound implications for environmental protection. In this work, a novel g-C 3 N 4 containing non-intrinsic oxygen vacancies (V O -CN) is synthesized via a facile oxygen pre-doping followed by elimination. Compared to pristine g-C 3 N 4 , V O -CN exhibits remarkably enhanced visible-light photocatalytic activity, increasing NO removal by 54.3%, with high NO 3 - selectivity. This photocatalytic enhancement is attributed to the non-intrinsic oxygen vacancies introduced in Vo-CN. As comprehensively revealed by experimental characterizations coupled with density functional theory (DFT) calculations. The results show that the midgap state generated in the V O -CN electronic band structure accelerates photogenerated electron-hole separation. Additionally, the unique surface structure of V O -CN provides favorable channels for carrier migration while enhancing O 2 and NO adsorption. Consequently, the markedly improved generation of reactive oxygen species by Vo-CN promotes highly efficient NO removal. This work provides novel insights into designing high-performance g-C 3 N 4 -based photocatalysts for eliminating hazardous NO pollutants. [Display omitted] • Non-intrinsic oxygen vacancies enable excellent photocatalytic NO removal activity. • Effect of midgap states in band structure on photogenerated carrier behavior. • local electrons induced by oxygen vacancies facilitate carrier generation and migration. • Active oxygen species generation and subsequent oxidation of NO. [ABSTRACT FROM AUTHOR]

In this paper, a new type of low molecular weight gelators (LMWGs), C2-symmetric benzene-based hydrogel (C2-BHG) with a 1,4-dimine benzene was self-assembled on glassy carbon electrode (GCE) and mica surface based on the hydrogen bond or hydrophobic interaction. Atomic force microscopy (AFM) characterization demonstrated the formation process of the C2-BHG hydrogel layer from particles to clusters, and finally to interconnected fiber network gel. The C2-BHG hydrogel layer resulted in the increase of the hydrophilicity of GCE surface. The C2-BHG modified GCEs (C2-BHG/GCE) with different assembly time were studied by cyclic voltammetry and electrochemical impedance spectroscopy in the presence of Fe(CN) 6 4−/3− redox probe. The rich amide and hydroxyl groups in the gel film make the C2-BHG/GCE suitable as ultrasensitive sensor for the detection of Cu(II) ions by stripping voltammetry with the limit of detection of 5×10 −10 g/L (S/N>3). Under the optimal conditions, the two linear ranges of Cu(II) ions were found to be 1×10 −9 ∼1×10 −7 g/L and 1×10 −7 ∼1×10 −4 g/L. The strong coordination interaction of C2-BHG with Cu(II) ions was confirmed by UV-Visible characterization. This new type of C2-BHG modified electrode was promising for highly sensitive Cu(II) ions sensor application due to high stability and excellent selectivity of the analytical signal. [ABSTRACT FROM AUTHOR]

In recent years, C 2 -symmetric supramolecular chiral gelators have emerged as a powerful tool for the construction of functional nanostructures to be applied in different fields. Myriad applications of these nanoscale architectures, in fields such as cell culture, dye adhesion and release, bacterial adhesion, tissue engineering, drug delivery, and chiroptical switches are being envisaged. This review attempts to present a succinct overview of the current state of research on functional nano-scale systems, the design, synthesis, and applications of self-assembled C 2 -symmetric supramolecular chiral gelators "engineered" to carry out precise functions, with an emphasis on the design on the basis of different cores for supramolecular self-assembly. This highlight gives a brief flavor of the development of C 2 -symmetric supramolecular chiral gelators broadly from the first decade of the 2000 s up to now. A particular theme is the emergence of C 2 -symmetric supramolecular chiral gels and increasing hi-tech niche application areas with respect to design and synthesis. Control and exploitation of design of C 2 -symmetric supramolecular chiral gels form a huge part of the grand challenge of directed assembly of extended structures with targeted properties and applications. [ABSTRACT FROM AUTHOR]

Abstract: Porous graphitic carbons encapsulating Fe nanoparticles (PGCFs) were fabricated by infiltrating activated carbon (AC) with an iron salt and thereafter heat-treating the products in vacuum, and the electromagnetic parameters of the PGCF were investigated over 2–18GHz frequency. The results demonstrated that the formation of porous graphitic network encapsulating Fe nanoparticles endowed the composite a very high permittivity and dielectric loss at 2–18GHz. Return loss (RL) for the PGCF-based absorbers were investigated based on the measured electromagnetic parameters. A typical dual-layer absorber exhibited an excellent microwave absorption with a 43dB maximum absorption at 10GHz and a nearly 7GHz bandwidth for RL<−20dB. [Copyright &y& Elsevier]

Chiral transcription and enantioselective separation have garnered significant research interests and showed potential for a broad range of practical applications. Here, we present a novel and facile strategy for chiral templating and enantiomers resolution by coating metal-ion-mediated l -phenylalanine derivatives (LPF/M) with graphene oxide (GO) via simply mixing. The LPF/M hydrogels precipitate from the liquid by encapsulation of GO through coordination interactions and hydrogen bonds, making heterogeneous transfer and separation possible. The chirality inversion of the internal LPF/M nanostructure could be triggered by different addition of metal ions, which further provides means for controlled chiral transfer of guest molecules on the outer GO surfaces as demonstrated in the transcription of thioflavin T (ThT) and 3-aminopyridine (AP) at the supramolecular level. Changing the metal ions also provides control over enantiomer selectivity with outstanding efficiency and reproducibility, as revealed by the separation of racemic mixtures of phenylanine (>98%), lysine (>96%), and histidine (>97%). In addition, the resultant hybrid materials exhibit excellent environmental stability and reusability (more than 20 times) with significant separation efficiency. More importantly, the GO-coated LPF/M could determine the enantiomeric composition of various chiral substrates. The proposed strategy opens up a promising avenue for practical chiral separation application. Image 1 [ABSTRACT FROM AUTHOR]

• A new method of selectively recognizing melamine and cyanuric acid by supramolecular interactions of gelation. • Chirality inversion and amplification was observed for LPF-co-CA and LPF-co-MA systems respectively. • Highly stable LPF-co-MA and LPF-co-CA gels were obtained in comparison to the LPF alone. Molecular recognition of achiral structural analogues, a remaining challenge for materials scientists and chemists, is the key to manipulating the applications and properties of supramolecular chiral materials. Herein, we report the molecular recognition of two harmful structural analogues i.e. melamine (MA) and cyanuric acid (CA) by using C 2 -symmetric phenylalanine chiral hydrogelators. Two distinct molecular recognition events between hydrogelator fibrils and triazine based achiral molecules are demonstrated: phenylalanine-co-melamine (PF-co-MA) gels showed chirality amplification while chirality inversion was observed for phenylalanine-co-cyanuric acid (PF-co-CA) gels. Moreover, viscoelastic properties and twist pitch were also regulated under the influence of the achiral molecules. Such phenomenon is mainly mediated by H-bonding among the two components, which may subtly change the arrangement of the molecules, in turn, the self-assembled nanostructures. This method of using C 2 -symmetric phenylalanine based gelators in the recognition of the achiral molecules may be broadly applicable for a wide variety of molecular recognition partners such as sugars. [ABSTRACT FROM AUTHOR]

Abstract: Butterfly wing skeleton is a widely used hard-template in recent years for fabricating photonic crystal structures. However, the smallest construction units for the most species of butterflies are commonly larger than ∼50nm, which greatly hinders their applications in designing much smaller functional parts down to real “nano scale”. This work indicates, however, that hollow ZrO2 nanowires with ∼2.4μm in length, ∼35nm in diameter and ∼12nm in wall thickness can be synthesized via the selection of suitable butterfly bio-templates followed by heat processing. Especially, the successful fabrication of these naturally cross-linked ZrO2 nanotubes suggests a new optional approach in fabricating assembled nano systems. [Copyright &y& Elsevier]

Abstract: A sonochemical method was introduced to synthesize SnO2 nanoparticles in the pores of mesoporous carbon without any other agents. The nitrogen adsorption measurement and transmission electron microscopy results revealed that the SnO2 nanoparticles with the average particle size of around 10nm were homogeneous distribution in the matrix. The aggregation of SnO2 was hindered by the three-dimensioned porous frameworks, resulting in a relatively large surface area of 362m2 g−1, which is beneficial for lithium-ion storage in batteries. The resultant composites with 43% SnO2 exhibited a high reversible capacity of 200mAhg−1 even after 300 cycles, which is 186% higher than that of the initial mesoporous carbon matrix. This strategy is expected to incorporate other functional nanoparticles inside mesoporous carbon for many applications. [Copyright &y& Elsevier]

Abstract: Using ultrasonication we succeed in a controlled incorporation of TiO2 nanoparticles on the graphene layers homogeneously in a few hours. The average size of the TiO2 nanoparticles was controlled at around 4–5nm on the sheets without using any surfactant, which is attributed to the pyrolysis and condensation of the dissolved TiCl4 into TiO2 by ultrasonic waves. The photocatalytic activity of the resultant graphene–TiO2 composites containing 25wt.% TiO2 is better than that of commercial pure TiO2. This is partly due to the extremely small size of the TiO2 nanoparticles and partly due to the graphene–TiO2 composite structure consisting of homogeneous dispersion of crystalline TiO2 nanoparticles on the graphene sheets. As the graphene in the composites has a very good contact with the TiO2 nanoparticles it enhances the photo-electron conversion of TiO2 by reducing the recombination of photo-generated electron–hole pairs. [Copyright &y& Elsevier]