RSC Advances最新文献

Two-dimensional (2D) chalcogenide materials have recently attracted significant research interest due to their exceptional anisotropic properties and tunable electronic structures, making them strong contenders for advanced thermoelectric and optoelectronic technologies. In this work, we conduct a detailed first-principles study to explore the structural, electronic, optical, and thermoelectric properties of the Mg₂In₂S₅ monolayer. Phonon dispersion and calculated elastic constants confirm the material's dynamic and mechanical stability. Electronic band structure analysis reveals a direct band gap semiconductor with a moderate band gap of 1.76 eV, making it suitable for visible light absorption. The partial density of states shows notable hybridization between In-5p and S-3p orbitals, which plays a key role in charge transport behavior. Optical simulations highlight strong anisotropy in the dielectric function and absorption spectra, with pronounced absorption in the UV-visible range, underscoring the material's potential in photonic and solar energy applications. Thermoelectric properties, evaluated using the Boltzmann transport formalism, display directional dependence, high Seebeck coefficients, and strong power factors. Remarkably, the figure of merit (ZT) reaches values as high as 1.0 in-plane and 1.2 out-of-plane at elevated temperatures, indicating excellent performance for high-temperature thermoelectric applications. Overall, the Mg₂In₂S₅ monolayer demonstrates outstanding optoelectronic and thermoelectric characteristics, positioning it as a highly promising 2D material for energy harvesting and future nanoelectronic technologies.

Ensuring food safety is an escalating global priority due to the rising risk of contamination and the necessity for meticulous monitoring of food quality. Fluorescent nanomaterials, specifically carbon dots (CDs), have garnered interest among new technologies for their potential in sensitive and speedy detection systems. Nitrogen doping has become a pivotal approach for augmenting the optical and electrical characteristics of carbon dots, owing to nitrogen's elevated electronegativity and its capacity to produce functional groups and trap states that enhance photoluminescence and sensor efficacy. Nitrogen-doped carbon dots (N-CDs) have exceptional biocompatibility, stability, and adjustable fluorescence, rendering them suitable for food safety applications. This review article presents an overview of the synthesis methods for N-CDs and their application in food sensing. Particular uses encompass the identification of heavy metals, antibiotics, food colourants, and spoilage indicators. The review addresses contemporary obstacles in synthesis, reproducibility, and practical integration, while delineating future directions for the advancement of N-CD-based sensing in food safety monitoring.

Copper matrix composites are engineering materials widely used in electrical and electronic applications. Therefore, enhancing their mechanical, electrical and thermal properties is essential. In this work, some results on the preparation of silicon carbide coated carbon nanotube nanowire (SiC@CNT NWs) reinforced copper (Cu) matrix composites were presented. SiC@CNT NWs prepared using a chemical vapor deposition method were mixed with Cu powder and then consolidated by spark plasma sintering to obtain SiC@CNTNW/Cu composites. The effects of SiC@CNT NW content on the microstructure, mechanical properties, tribological behavior, electrical and thermal properties were examined. Incorporation of 3 vol% SiC@CNT NWs enhanced hardness and ultimate tensile strength by 71% and 64%, respectively, while reducing the coefficient of friction (COF) by 40% and specific wear rate by 53%. These improvements are attributed to the SiC@CNT structure, which offers superior reinforcement efficiency. The coefficient of thermal expansion decreased with increasing nanowire fraction, consistent with the inherently lower CTE of SiC@CNT NWs. Based on Turner's model, the CTE and Young's modulus of the nanowires were estimated at 1.8 × 10⁻⁶ K⁻¹ and 680 GPa, respectively.

In this study, we explore the self-assembly of zinc meso-tetra (4-pyridyl) porphyrin (Zn-TPyP) into nanotubes via a surfactant-assisted micelle formation strategy under kinetic control. Incorporating a chiral surfactant bearing alkyl chains and carboxylic acid groups proved essential for stabilizing micelle formation, thereby suppressing spontaneous assembly into thermodynamically favored structures. This encapsulation-induced micelle formation enables the kinetically controlled nucleation and anisotropic growth of Zn-TPyP nanotubes. Notably, the resulting nanotubes exhibited photocatalytic activity by effectively degrading methyl orange (MO) under visible light irradiation. Our study provides mechanistic insight into kinetic control of self-assembly processes and demonstrates the potential of micelle encapsulation as a versatile tool for engineering functional metallo-supramolecular materials with tailored functional properties.

The practical application of supercapacitors is often limited by their low energy density, which stems from restricted voltage windows and insufficient redox reactions. Here, a symmetric supercapacitor device combining phosphorus-doped mesoporous graphitic carbon nitride (P-Mg-CN) electrodes with a redox-mediated gel polymer electrolyte (R-mgpe) is developed. In a three-electrode configuration, P-Mg-CN exhibited a specific capacitance of 134 F g⁻¹ in 1 M H₂SO₄, which increased to 398 and 207 F g⁻¹ in hydroquinone-based redox electrolytes, respectively, respectively, due to additional faradaic contributions from the I⁻/I₃⁻ and hydroquinone/benzoquinone (HQ/BQ) redox couples. The device exhibits a broad voltage window of 1.4 V and achieves a high specific capacitance of 142 F g⁻¹ at a current density of 2 A g⁻¹. It also delivers an energy density of 38.66 Wh kg⁻¹ at a power density of 2.8 kW kg⁻¹. Furthermore, it retains 95.89% of its initial capacitance after 10 000 cycles. These results demonstrate that integrating redox-mediated gel electrolytes with heteroatom-doped carbon nitrides effectively increases the energy density of symmetric supercapacitors while maintaining long-term stability.

Microfluidic paper-based analytical devices (µPADs) are considered a key solution as they offer a low-cost platform for developing point-of-need (PON) biosensors for cancer biomarker/cell detection. Nanomaterials utilized in the structures of µPADs and PADs provide powerful tools for the early-stage diagnosis of cancer. This review aims to summarize the recent advances in a variety of µPADs and PADs used for cancer diagnosis based on different types of nanomaterials, such as metal/metal oxide nanoparticles, magnetic nanoparticles, quantum dots, and 1–3 dimensional materials. This review also discusses the properties and functions of various nanomaterials, highlighting their recent applications in PAD- and µPAD-based diagnosis of cancer biomarkers and cells based on immune-, apta-, geno-, peptide-, and enzymatic-biosensing. Additionally, the critical role of detection techniques, like electrochemical, optical (UV-Vis spectrophotometry, SPR, SERS, and fluorometry), electrochemiluminescent, photoelectrochemical, and piezoelectric methods, in label-free and labeled bio-assays of cancer biomarkers are surveyed. The advantages and limitations of various sensing methods, techniques, types of materials and fabrication strategies are surveyed to explore the best cases for cancer diagnosis using PADs and µPADs. The roles of novel technologies such as AI and IOT, in the development of PAD- and µPAD-based cancer diagnosis are investigated. Finally, a comparison of the advantages and limitations of PADs and µPADs in the early-stage diagnosis of various cancers is reviewed towards exploring the research/technological gaps.

Photocatalysis and persulfate-based advanced oxidation technologies have received considerable attention. In this study, a Z-scheme heterojunction photoanode composed of graphitic carbon nitride and titanium dioxide (TiO₂/g-C₃N₄) was constructed to develop an efficient photoelectrochemical–persulfate (PEC/PMS) activation system for antibiotic degradation. The PEC/PMS system significantly accelerated electron transfer and enhanced the photoresponse current, achieving 96.04% tetracycline removal within 12 min. The optimal operating conditions were a bias voltage of 1.0 V, a PMS concentration of 0.2 mmol L⁻¹, and a neutral to slightly alkaline environment. The system effectively resisted interference from water matrix components and achieved over 88% removal of multiple antibiotics in aquaculture pond water. TiO₂/g-C₃N₄ exhibited a Z-scheme heterostructure, and its photocatalytic activity served as the primary driving force in the synergistic process, in which degradation was dominated by radical pathways (˙OH and ˙SO₄⁻) accompanied by a non-radical ¹O₂ pathway. The calculated synergy factor further confirmed that the introduction of an external electric field and PMS markedly enhanced electron transfer and produced a pronounced synergistic effect.

Withania coagulans Dunal is a medicinal plant with potential therapeutic applications in neurodegenerative and metabolic disorders. This study aimed to isolate, structurally characterize, and evaluate the biological potential of withanolide-type compounds from Withania coagulans Dunal, with a focus on their antioxidant and enzyme inhibitory activities relevant to neurodegenerative and metabolic disorders. Two new withanolides (WTH1 and WTH2) and one known compound (WTH3) were isolated from W. coagulans. The methanol extract and its fractions were assessed for total phenolic and flavonoid contents, antioxidant capacity (DPPH, FRAP, phosphomolybdenum assays), and enzyme inhibitory activities against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), lipoxygenase, α-glucosidase, and tyrosinase. The methanol extract exhibited the highest total phenolic (71.53 mg GAE per g) and flavonoid (64.32 mg QE per g) contents, correlating with strong antioxidant activity (DPPH: 91.2%, FRAP: 678.3 µmol Fe²⁺ per g, phosphomolybdenum: 4.2 mmol TE per g). It showed significant inhibitory effects against AChE (4.10 mg GALAE per g), BChE (3.71 mg GALAE per g), lipoxygenase, α-glucosidase, and tyrosinase, with the ethyl acetate fraction displaying the strongest α-glucosidase inhibition (3.51 mmol ACAE per g). In silico docking revealed strong binding affinities of WTH1 and WTH3 toward AChE (−11.616 and −11.438 kcal mol⁻¹, respectively), while WTH3 also interacted effectively with BChE (−9.30 kcal mol⁻¹), surpassing the standard drug physostigmine (−5.85 kcal mol⁻¹). Pharmacokinetic evaluation of WTH1 predicted high gastrointestinal absorption (97.65%), moderate oral bioavailability (0.55), and absence of hepatotoxicity or AMES toxicity. DFT analysis indicated a stable HOMO–LUMO energy gap (9.923 eV), and binding free energy calculations confirmed strong interaction of WTH1 with AChE using PB (−29.731 kcal mol⁻¹) and GB (−43.54 kcal mol⁻¹) methods, outperforming the reference drug (−15.08 kcal mol⁻¹). The findings demonstrate that W. coagulans methanol extract, particularly the isolated new withanolide WTH1, exhibits potent antioxidant and enzyme inhibitory activities with promising pharmacokinetic properties. These results support further pharmacological and clinical evaluation of W. coagulans as a natural source of therapeutic agents against neurodegenerative and metabolic disorders.

Organic selenium shows promise in cancer treatment due to its antioxidant properties, however, challenges like toxicity and instability hinder its efficacy. Herein, we aim to develop stable and less toxic selenium-chelated tuna bone gelatin peptides (TBGP@Se). TBGPs were extracted from tuna bones and chelated with selenium through a redox reaction. The resulting TBGP@Se was characterized to assess amino acids sequences, morphology of TBGP@Se, particle size distribution. Antiproliferation activity was evaluated using A549 and HT-29 cell lines. Our TBGP@Se was rich in glycine, proline, and alanine which aided stable Se chelation. Electron micrography confirmed gelatin concentrations (5 mg mL⁻¹) with stable TBGP@Se complexes. FTIR and DLS analyses further confirmed successful Se chelation and improved particle dispersion. TBGP@Se exhibited potent antiproliferative effects in vitro. Collectively, our study demonstrates the successful synthesis of stable TBGP@Se with significant antiproliferative activity against cancer cells in vitro. Future research should explore the mechanisms of action and validate these findings in animal models to advance TBGP@Se towards clinical applications in cancer treatment.

The nanostructured iron nitride phases, comprising only non-toxic and abundant elements, show potential in a wide range of applications, and are thus of great interest in the context of sustainable development. Especially, the nanostructured ε-Fe_xN phase (x = 2–3) can play the role of electrocatalyst (in fuel cells or for hydrogen production), or of anode in Li-ion batteries. However, obtaining morphology and composition (x) controlled nanoparticles of this phase is challenging. Here we show that α-Fe nanoparticles produced by an organometallic approach can be nitridated by a simple exposure to an ammonia flow in mild conditions of temperature, either in the powder form or as thin layers on FTO electrodes while keeping their initial morphology. Structural and magnetic measurements, combined with chemical analysis, and spectroscopic investigations evidenced the formation of the pure ε-Fe₂N phase, with a preserved nanostructure. The electrocatalytic activity of this nanomaterial has been evaluated for CO₂ reduction and for the oxygen evolution reaction. These results may open new perspectives for studying the properties and reactivity of ε-Fe₂N nanomaterials, and promote their use.