Journal of Cluster Science最新文献

This work reports the synthesis of cationic surfactant-coated Au-Ag core-shell (Au@Ag) nanoparticles (NPs) via a straightforward seed-mediated approach. The UV-Vis analysis showed that the plasmon peak position of synthesized Au@Ag NPs correlated with the thickness of the Ag shell encapsulating the Au core. The Au@Ag NPs have shown impressive catalytic performance for the reduction reactions of 4-nitrophenol (4-NP) and methyl orange (MO) where the apparent rate constant experienced a remarkable increase by 67-fold and 90-fold, respectively, when Au@Ag NPs with the Ag-shell thickness of 6.3 nm were employed as a catalyst, compared to Au NPs. This multifold improvement in the activity cannot be simply accounted for by the increase in surface area of NPs and is attributed to the electronic synergistic effects between Au and Ag in the core-shell NPs. Furthermore, while Au@Ag NPs exhibited heightened antibacterial activity against both Gram-positive S. aureus and Gram-negative E. coli bacteria, this enhancement is modest. Notably, the anticipated significant enhancement attributed to Ag's renowned antibacterial properties was not observed. The presence of cationic surfactant cetyltrimethylammonium bromide (CTAB) enables both Au and Au@Ag NPs to effectively bind with the negatively charged bacterial cell membranes through electrostatic interactions. Apparently, CTAB enables both types of NPs to effectively target and eliminate bacteria with comparable efficiency.

The natural physiological response to skin injury is wound healing. However, to restore skin continuity, wound healing is a complicated process that involves the collaboration of a variety of cell types and other mediators. This process ultimately results in tissue regeneration and the restoration of skin barrier function. Hydrogels are appealing dosage forms for biomedical regenerative medicine since they are composed of 3D networks with high water content and flexible rheological features. Hydrogels that can self-heal are particularly interesting for wound treatment because they can autonomously restore their original functionalities and repair structural damage. Recently, the use of self-healing hydrogels as biomedical materials has attracted increased interest. In this review, the self-healing systems used in tissue regeneration, especially wound healing, will be explored. A focus on the fabrication methods, characterization tests, and mechanism of self-healing will be introduced, along with the biomedical applications of self-healing hydrogels loaded with conventional and therapeutic biomaterials. In addition, the differences between hydrogels and self-healing hydrogels will be discussed.

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In this work, we study the magnetocaloric properties of half 5/2 and integer 3 mixed spin model on a square–hexagon «4-6» structures are studied by Monte Carlo simulations. The total magnetization and the magnetization of each sub-lattice of the mixed-spin lattice have been analyzed. The magnetic susceptibility, dM/dT and magnetic entropy changes are found. The magnetic hysteresis cycles under, with the temperatures, exchange interactions (S-S), (σ-σ) and (σ-S), and the crystal fields (D_σ and D_S) has been discussed.

Alloyed nanoclusters have been widely reported, but controllable synthesis of predesigned nanoclusters with specific structures remains challenging. We used [Cu(MeCN)₄]PF₆ intercept (Ag^tBuC≡C)_n polymer to form Ag(I)-Cu(II) oligomer precursors which serve as the starting point of co-reduction reaction, leading to the generation of a new [Ag₈Cu₇(^tBuC≡C)₁₂]PF₆ (Ag₈Cu₇) nanocluster. Single-crystal diffraction result reveals its Cu@Ag₈@Cu₆(^tBuC≡C)₁₂ three-layer structure similar to the previously reported Ag₉Cu₆ nanocluster except for the different core atom and shorter bond distance around. The identification of Ag₈Cu₇ was further confirmed by ESI-MS, XPS, PXRD, and TG characterizations. Besides, the nonemissive Ag₈Cu₇ cluster was subject to ligand exchange of bulky ligand 3,5-bis(trifluoromethyl)phenylacetylide (ArC ≡ CH) giving a novel Ag₁₀Cu₄(ArC ≡ C)₁₄(DPPB)₂ (Ag₁₀Cu₄) with a 634 nm red light emission, which provides another example of the breakage-reassembly mechanism.

The current study describes the preparation of nano-formulation of propyl gallate (NPG vesicles) comprised of soya bean extracted soya-lecithin. The compound was evaluated for its in-vitro and in-vivo anti-oxidative and anti-inflammatory properties in addition with acute toxicity analysis in Wistar rats. Nano-carrier preparation acquired the film hydration method, while the evaluation for size distribution was carried out through dynamic light scattering (DLS) analysis. FTIR spectroscopy was used to identify the interaction between active material with excipient. Whereas, morphological evaluation was carried out by using atomic force microscopy (AFM). UV-visible spectrophotometer was used to measure the efficacy for drug encapsulation. The synthesized nano-carriers of propyl gallate has particle size of 201 ± 2.5 nm, with spherical morphology. The PDI index of nano-formulation is; 0.192 ± 0.8 indicates uniform size distribution with zeta potential − 43.4 ± 1.7mV values representing their highly stable nature. The drug encapsulation efficiency of the NPG vesicles was found to be 52%. The nano-formulation reveals the in-vitro anti-oxidative and anti-inflammatory properties and showed non-toxicity on normal human fibroblast cell line as compared to the parent compound propyl gallate. NPG vesicles showed prominent anti-inflammatory potential against carrageenan induced paw edema and found to be non-toxic in Wistar rats in acute toxicity studies for seven days. In conclusion, nano formulation NPG vesicles showed effective anti-oxidative and anti-inflammatory effects both in-vitro and in-vivo and has the efficacy to become a potential modulator for targeted therapy.

Mercury (Hg²⁺) as environmental pollutant is a widespread concern due to its cytotoxic effect in humans and animals and needs to be monitored through cost effective methods based on naked-eye detection. Herein, in this study, we extracted and isolated the limonin (LMN) via a facile procedure and then employed it as capping agent for the synthesis of silver nanoparticles (LMN-AgNPs) as a first report. LMN-AgNPs were characterized through Field Emission Scanning Electron Microscopy (FESEM), Atomic Force Microscopy (AFM), Dynamic Light Scattering (DLS), Zeta Potential Analyzer (ZPA) and Fourier Transform Infrared (FTIR) spectroscopy. As-formed LMN-AgNPs were recognized as extremely selective and highly sensitive colorimetric sensor for Hg²⁺ with potential analytical application. The developed sensor showed an outstanding linear correlation with the concentration of Hg²⁺ in the range of 0.002 − 55 µM via a color change from deep yellow to transparent showing hypsochromic-hypochromic shift with the limit of detection (LOD) and the limit of quantification (LOQ) as low as 0.21 nM and 0.7 nM respectively. The sensor was further allied with smartphone for immediate and on-site quantification of Hg²⁺. The LOD and LOQ of 0.42 µM and 1.4 µM was true for smartphone based sensing in the range of 7.5–55 µM Hg²⁺. The detection of Hg²⁺ was not disrupted by the presence of other metals in either of mentioned cases. The practical applicability of the proposed Hg²⁺ sensor was tested using spectrophotometric and smartphone based approaches in human serum and urine as well as in tap water samples with acceptable ranges of recovery. As-developed sensor can work as a potential candidate for monitoring of Hg²⁺ pollution in diverse fields of studies.

Chemical sensors are detecting probes that translate information of analyte into a quantifiable signal for chemical exploration studies. Fabrication of (E)-2-(5-chloro-2-hydroxy-3-iodobenzylidene) hydrazine-1-carboxamide stabilized silver nanoparticles (1c-AgNPs) is one-dimensional synthesis avenue in present study exhibiting the ability of metal cations detection and selectivity of sensing mercury (Hg²⁺) ions in various samples of water and cosmetic creams. The newly synthesized silver nanoparticles (AgNPs) were comprehensively elucidated by ultraviolet-visible spectroscopy, Fourier-transform infrared (FTIR), zeta-sizer, atomic force microscopy (AFM), X-ray diffraction (XRD), Scanning electron microscopy (SEM) and thermal degradation analysis. 33.2 ± 1.3 nm sized polydispersed nanoparticles showed selective, sensitive and efficient detection of Hg²⁺ ions with detection limit of 0.274 µM by significant quenching in UV-Vis spectral band at 410 nm in real water and cosmetic cream samples. The theoretical findings displayed changes in reactive descriptors, electronic parameters, bond angles, and bond lengths of 1c and conjugated AgNPs using DFT method. The biological application of 1c-AgNPs showed significant synergistic potential as antibacterial agent against Escherichia coli and Staphylococcus aureus compared to ligand. Thus, the newly engineered 1c-AgNPs could be a favorable appliance in nature and health restoration.

An emerging material, cobalt oxide (Co₃O₄) may be useful for a number of promising technological applications, including energy conversion and storage devices. Among the limiting factors of Co₃O₄ are its small surface area as well as its poor electrical conductivity. Our study describes the controllable synthesis of Co₃O₄ nanostructures using a renewable source in the form of potato peel extract, which is an abundant and inexpensive source of starch. Surface active features were observed along with significant changes in structure, crystal orientation, and surface chemical composition. As a result of detailed characterization of phase purity, shape orientation, crystal structure, and surface chemical composition, the as-synthesized Co₃O₄ nanostructures were fabricated as electrode materials and investigated for supercapacitors and oxygen evolution reactions (OER) applications. The optimized Co₃O₄ nanostructures comprising 10 mL of potato peel extract have demonstrated a highly improved pseudo-capacitance performance with a specific capacitance of 1453.13Fg^− 1 and a specific energy density of 32.29 Wh/Kg at a current density of 1.25 Ag^− 1 in 3.0 M KOH electrolytic solution. It was determined that the electrode materials have a cycling stability of 96–99% over 30,000 repeatable cycles with a columbic efficiency of 95–100%, which indicates the high practicality of the electrode materials. The OER performance of 10 mL of potato peel extract assisted Co₃O₄ nanostructures was also evaluated using 1.0 M KOH. An fabricated Co₃O₄ nanostructure derived from potato peel extract exhibited an overpotential of 260 mV at 10 mAcm^− 2 and a Tafel slope of 72 mV dec^− 1 in 1.0 M KOH. Furthermore, the constructed electrode material was extremely durable for a period of 30 h at two different constant-current densities of 20 mAcm^− 2 and 40 mAcm^− 2. Among the attributes that contribute to the superb performance of the newly developed Co₃O₄ electrode materials are the fascinating morphology, the reduced size, the enriched active surfaces, and the high degree of compatibility. Overall, the findings of this study establish that potato peel extract can serve as a valuable source of starch for the development of next-generation of electrode materials for efficient energy storage and conversion systems.

The novel flower shaped nanomaterials, known as Nanoflowers (NFs), have attracted the interest of the scientific community around the world with their unique morphology, ease of synthesis, large surface-to-volume ratio, and high electron conductivity, making them a promising nanomaterial for various relevant applications. Bimetallic NFs comprise of two different metallic elements, with superior properties due to the synergistic effect between the hereditary properties of the constituent metal atoms. Bimetallic NFs can be synthesized through various methods, each offering unique advantages. Conventional methods provide a traditional approach to NF synthesis, while electrodeposition methods offer precise control over NF morphology and composition. Biological methods harness the power of biological systems for green and sustainable NF synthesis. Various characterization techniques for identifying the morphology of NFs include HR-TEM, SEM, EDX, XRD etc. These NFs exhibit exemplary catalytic activity with high selectivity and catalytic yield due to their large surface areas and augmented active site density. This review delineates the synthesis, morphology, electronic properties and catalytic applications of bimetallic NFs. The manuscript depicts various catalytic reactions and focuses on mechanism and role of bimetallic NFs in these reactions. Moreover, the recent challenges and future prospects of these bimetallic NFs are well discussed in detail.

In contrast to zinc oxide (ZnO), the antibacterial potential of zinc hydroxyacetate (Zn-HA) remains unexplored. In this study, we fabricated alginate/TEMPO-oxidized nanocellulose (AT) hydrogels containing three types of zinc particles (Zn Ps): Zn-HA, Zn-N (ZnO nanoparticles), and Zn-C (commercial ZnO). The antibacterial efficacy of these hydrogels was assessed and compared. The integration of Zn Ps into AT hydrogels was achieved through a facile method, resulting in the formation of composite hydrogels with layered three-dimensional structures. The addition of Zn Ps reduced the mechanical properties and swelling ability of the hydrogels. The antibacterial activities of the Zn Ps and hydrogels were evaluated using the disc diffusion method. Surprisingly, Zn-HA exhibited significantly stronger antibacterial efficacy against both E. coli and S. aureus, with the zone of inhibition (ZOI) ranging from 11 mm to 19.7 mm compared to Zn-C and Zn-N (ZOI of 8.3–9.3 mm). This improved antibacterial activity might be attributed to the higher release of Zn²⁺ from Zn-HA (7.5 mg/100 mL compared to 0.8 and 1.2 mg/100 mL), as evidenced by the zinc dissolution study. The antibacterial activity of the AT hydrogels was significantly enhanced by the inclusion of Zn-HA but not Zn-C or Zn-N. All hydrogels exhibited mild toxicity to human skin fibroblasts. In summary, our findings challenge the expectation that ZnO (Zn-C and Zn-N) would have better antibacterial properties due to their smaller particle sizes in comparison to Zn-HA microparticles. Additionally, our results indicate that converting Zn-HA to ZnO is unnecessary to impart antibacterial properties to the hydrogels. Thus, AT hydrogels containing Zn-HA (ATZ-HA) can potentially be used as advanced antibacterial materials, possibly for use in wound dressings.

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