Nanoscale Advances最新文献

Doping in pure materials causes vital alterations in opto-electrical and physicochemical characteristics, which enable the produced doped material to be highly efficient and effective. The current work focused on the synthesis of C/N-co-doped-ZnO nanorods via a facile, eco-friendly, and solvent-free mechano-thermal approach. The synthesized C/N-co-doped ZnO nanorods were employed for the photocatalytic decay of methylene blue (MB) and brilliant cresyl blue (BCB) dyes, and their degradation capability was compared with that of pure ZnO nanoparticles prepared via a precipitation approach. The FESEM findings confirmed the formation of rod-shaped nanostructures of co-doped ZnO nanoparticles, and EDX and XPS results revealed the successful doping of C and N atoms in ZnO lattices. The XRD and XPS results substantiated that N-doping in the ZnO lattice followed substitutional and interstitial mechanisms, while C-doping followed a substitutional pathway. The co-doped ZnO nanorods exhibited highly enhanced degradation potential toward both MB (∼99%) and BCB (∼98%) dyes upon exposure to visible light for 60 min in a basic medium at pH = 10 owing to factors such as formation of new energy states within the band gap of ZnO, delayed recombination of photogenerated charge carriers, and formation of lattice defects in the ZnO lattice due to C and N doping. The MB and BCB dyes photodegraded at degradation rates of 637.23 × 10^-4 and 775.25 × 10^-4 min^-1, respectively, and the photodegradation process showed good agreement with the pseudo-first-order kinetics in the presence of co-doped ZnO nanorods under visible light illumination. The ˙O₂ ^- radicals were the key reactive species involved in the decay of MB and BCB dyes over co-doped ZnO, as confirmed via scavenger studies, and the C/N-co-doped ZnO nanorods retained approximately 90% and 91% efficiencies for BCB and MB dyes, respectively, after three successive cycles of reuse, which confirmed their good stability and reusability under visible light.

Bone remodeling, a continuous process of resorption and formation, is essential for maintaining skeletal integrity and mineral balance. However, in cases of critical bone defects where the natural bone remodeling capacity is insufficient, medical intervention is necessary. Traditional bone grafts have limitations such as donor site morbidity and availability, driving the search for bioengineered scaffold alternatives. The choice of biomaterial is crucial in scaffold design, as it provides a substrate that supports cell adhesion, proliferation, and differentiation. Poly-lactic acid (PLA) is known for its biocompatibility and biodegradability, but its hydrophobicity hinders cell attachment and tissue regeneration. To enhance PLA's bioactivity, we fabricated 3D-printed PLA scaffolds using fused deposition modelling. They were then surface-treated with NaOH to increase their reactivity, followed by polydopamine (PDA) and 4-methoxycinnamic acid (MCA)-loaded chitosan nanoparticle (nCS) coatings though polyelectrolyte complexation. Even though MCA, a polyphenolic, is known for its therapeutic properties, its osteogenic potential is not yet known. MCA treatment in mouse mesenchymal stem cells (mMSCs) promoted increased levels of Runx2 mRNA, a key bone transcription factor. Due to MCA's hydrophobic nature, nCS were used as carriers. The PLA/PDA/nCS-MCA scaffolds exhibited exceptional compressive strength and bioactivity. Biocompatibility tests confirmed that these scaffolds were non-cytotoxic to mMSCs. Overall, this study highlights the osteogenic potential of MCA and demonstrates the improved biocompatibility, bioactivity, wettability, and cell adhesion properties of the PDA/nCS-MCA-coated PLA scaffolds, positioning it as a promising material for bone tissue regeneration.

Two-dimensional (2D) hybrid materials, particularly those based on boron nitride (BN) and graphene oxide (GO), have attracted significant attention for energy applications owing to their distinct structural and electronic properties. BN/GO composites uniquely combine the mechanical strength, thermal stability and electrical insulation of BN with the high conductivity and flexibility of GO, creating advanced materials ideal for the fabrication of batteries, supercapacitors and fuel cells. These hybrids offer synergistic effects, enhanced charge transport, increased surface area, and improved chemical stability, making them promising candidates for high-performance energy systems. Despite their potential, challenges, such as achieving scalable synthesis and uniform BN-GO dispersions and poor interface compatibility, have limited the widespread adoption of BN-GO hybrids. To address these limitations, this study is focused on the scalable synthesis of BN-GO composites via a liquid-phase exfoliation method with ultrasonication, followed by preparation of sodium thiosulfate (STS)-functionalized BN-GO composites (STBG), which exhibited high electrochemical properties suitable for energy storage. The structural identification was confirmed using FT-IR, Raman, XRD, and UV-vis spectroscopy. Thermal stability of the samples was assessed by TGA, while their morphological analysis was performed using HR-TEM, TEM, and SEM. Pristine BN showed negligible efficiency, whereas STS functionalization elevated the efficiency of STBN to 81.7%, while the incorporation of GO in STBG1 and STBG2 boosted their efficiency to 89.3% and 83.3%, respectively. STBG1 exhibited a nearly rectangular, symmetrical CV curve at various scan rates, demonstrating excellent capacitive behavior. Furthermore, it achieved the highest specific capacitance of 115.82 F g^-1 at a current density of 1 A g^-1, together with a coulombic efficiency of 89.3%, indicating its superior charge transfer and minimal energy loss. Additionally, STBG1 retained 87.3% of its capacity, while STBG2 retained 81.7% even after 3000 charge/discharge cycles. These findings highlight that STBG1 is a promising composite with high capacitance, strong rate capability, and exceptional coulombic efficiency, making it a viable candidate for next-generation energy storage systems.

Extracellular vesicles (EVs) are emerging as viable tools in cancer treatment due to their ability to carry a wide range of theranostic activities. This review summarizes different forms of EVs such as exosomes, microvesicles, apoptotic bodies, and oncosomes. It also sheds the light onto isolation methodologies, characterization techniques and therapeutic applications of all discussed EVs. Evidence indicates that EVs are particularly effective in delivering chemotherapeutic medications, and immunomodulatory agents. However, the advancement of EV-based therapies into clinical practice is hindered by challenges including EVs heterogeneity, cargo loading efficiency, and in vivo stability. Overall, EVs have the potential to change cancer therapeutic paradigms. Continued research and development activities are critical for improving EV-based medications and increasing their therapeutic impact.

In this study, we used two-dimensional electronic spectroscopy to examine the early femtosecond dynamics of suspensions of colloidal gold nanorods with different aspect ratios. In all samples, the signal distribution in the 2D maps at this timescale shows a distinctive dispersive behavior, which can be explained by the interference between the exciting field and the field produced on the nanoparticle's surface by the collective motion of electrons when the plasmon is excited. Studying this interference effect, which is active only until the plasmon has been dephased, allows for a direct estimation of the dephasing time of the plasmon of an ensemble of colloidal particles. Our findings provide insight into the fundamental behavior of plasmonic states and highlight the potential of two-dimensional electronic spectroscopy in uncovering ultrafast and coherent optical phenomena at the nanoscale.

Heterostructuring of two-dimensional materials offers a robust platform to precisely tune optoelectronic properties through interlayer interactions. Here we achieved a strong interlayer coupling in a double-layered heterostructure of sulfur isotope-modified adjacent MoS₂ monolayers via two-step chemical vapor deposition growth. The strong interlayer coupling in the MoS₂(³⁴S)/MoS₂(³²S) was affirmed by low-frequency shear and breathing modes in the Raman spectra. The photoluminescence emission spectra showed that isotope-induced changes in the electronic structure and strong interlayer coupling led to the suppression of intralayer excitons, resulting in dominant emission from the MoS₂(³²S) layer. Time-resolved photoluminescence experiments indicated faster lifetimes in the MoS₂(³⁴S)/MoS₂(³²S) heterostructure compared to the conventional bilayers with the natural isotopic abundance, highlighting nuanced interlayer exciton dynamics due to the isotopic modification. This study underscores the great potential of isotope engineering in van der Waals heterostructures, as it enables tailoring the band structure and exciton dynamics at the nuclear level without the need of chemical modification.

Laser surface alloying of Fe, Si, and C on aluminium is demonstrated using a Q-switched Nd:YAG laser as the source of energy. The fundamental wavelength of the laser beam was 1064 nm with an output energy of 100 mJ and a pulse duration of 10 ns. The exposure was conducted in repetitive mode with a frequency rate of 1 Hz. The laser was focused to induce plasma formation. A pure aluminium plate was employed as the substrate to be alloyed. Iron (Fe) and ceramic material silicon carbide SiC were selected as the alloy elements. Two step deposition techniques were employed to predeposit the aluminium substrate. The substrate was painted with a cohesive material gum before powder spray coating on it. The predeposited aluminium was then exposed to a focused laser at various numbers of pulses (1-13 pulses). The resulting materials were examined via scanning electron microscopy (SEM), X-ray diffraction (XRD), and microhardness techniques, revealing the formation of a homogenized resolidified surface. The plasma temperature was much higher than the melting point of Fe and SiC, enabling an immediate interaction with coating materials. The different melting points of Fe, SiC, and Al allowed the formation of a new composite during quenching. The formation of such a new composite is identified via XRD analysis. Inherently, several new composites were revealed, such as Al-Fe-Si, SiAl, and Fe-Si, with enhanced mechanical strength. Apparently, the hardness of the modified surface is confirmed to be two times greater than that of the original substrate. The sensitivity of the MSM photodetector (PD) made of the resulting alloy is reasonably high and increases with increasing the bias voltage. The response times (T _Res) of the MSM PD for various numbers of laser pulses (1-13 pulses) were 0.60 s, 0.28 s, and 0.67 s with corresponding recovery times (T _Rec) of 0.53 s, 0.21 s, and 1.81 s, respectively.

Biofilms formed by several bacterial strains still pose a significant challenge to healthcare due to their resistance to conventional treatment approaches, including antibiotics. This study explores the potential of loading natural extracts with antimicrobial activities into β-cyclodextrin (βCD) nanoparticles, which are FDA-approved and have superior biocompatibility owing to their cyclic sugar structures, for biofilm eradication. An inclusion complex of βCD carrying Boswellia sacra essential oils (BOS) was prepared and characterized with regard to its physicochemical properties, antimicrobial efficacy, and antibiofilm activities. Encapsulation of BOS into βCD significantly enhanced the antimicrobial activity of BOS by 4-fold against Gram-positive (Staphylococcus aureus and Bacillus subtilis) and by 8-fold against Gram-negative (Escherichia coli and Pseudomonas putida) bacteria, with minimum inhibitory concentrations ranging from 2.5 to 5 mg mL^-1. Furthermore, the BOS-βCD complex demonstrated a dual-action against bacterial biofilms where it prevented biofilm formation and disrupted established biofilms. This resulted in a significant reduction in biofilm biomass, with prevention and disruption rates reaching up to 93.78% and 82.17%, respectively. Additionally, the formula revealed an excellent biocompatibility profile with no induction of oxidative stress in human skin fibroblast cells. Our findings suggest that βCD nanoparticles loaded with BOS essential oils hold promise as an effective formula for preventing the formation of bacterial biofilms and combating preformed ones for use in relevant medical applications.

This study presents a statistical analysis of how gold nanoparticle (GNP) size and polyethylene glycol (PEG) coating molecular weight (MW) affect the circulation of nanoparticles in blood. We showed a non-linear relationship with interaction between GNP size and PEG MW. The findings revealed a threshold effect, and recommendations for GNP coating are discussed.

Catalysis plays a vital role in green chemistry by improving process efficiency, reducing waste, and minimizing environmental impact. A biochar-modified g-C₃N₄·SO₃H (BCNSA) catalyst was developed using biochar derived from amla seed powder and CNSA. CNSA was synthesized via the reaction of g-C₃N₄ with chlorosulfonic acid. Both components were combined, pyrolyzed, purified, and comprehensively characterized using FTIR, XRD, FE-SEM, EDX, elemental mapping, TGA, and DTA studies to confirm the successful synthesis and structural integrity. The catalyst demonstrated exceptional efficiency in synthesizing bis-indole derivatives through reactions between substituted indoles (indole, 1-methyl indole, and 6-chloro indole) and carbonyl-containing compounds, including isatins (isatin, 7-(trifluoromethyl)isatin, 5-bromo isatin, and 5-fluoro isatin), aldehydes, cyclo-ketones, dimedone, and acetophenones. These reactions were carried out under simplified conditions using water as a green solvent, promoting sustainability and versatility. A total of 21 bis-indole products were synthesized within 5-45 minutes, achieving yields of 80-98% showcasing the catalyst's outstanding performance. Furthermore, the method was scaled up to gram-level synthesis, and green chemistry metrics were evaluated for all the products, highlighting the environmental and economic benefits of this approach.