The field of developing effective catalysts for heterogeneous catalysis has recently focused on controlling the structures of catalysts themselves to optimise the density and energy of crystal lattice defects. This can significantly influence catalytic activity in terms of both reaction rates and reaction mechanisms, and thus the selective production of desired substances as well. In many cases, these crystal lattice defects manifest themselves as so-called electron traps (ETs) and thus significantly influence charge transfer between the catalyst and reactants. ETs provide the missing electronic link between atomic-scale defects and macroscopic performance in heterogeneous catalysis. Therefore, the importance of ETs for catalysis is particularly evident in areas where charge transfer plays a fundamental role in the reaction mechanism, such as photocatalysis and electrocatalysis. In the field of thermally initiated reactions, the importance of ETs in heterogeneous catalysis has not yet been fully appreciated. However, several studies have already addressed the importance of ETs for this type of reaction. This review consolidates and extends the concept of ETs to purely thermal-initiated reactions, with a focus on CO2 hydrogenation using typical transition metal catalysts. Firstly, in this review, ETs are defined as band gap states associated with internal and external defects, and their depth, density, spatial location, and dynamics are then coupled with key steps in thermocatalytic cycles, including charge storage/release, reactant activation, intermediate stabilisation, and redox turnover. Secondly, electron trap detection is reviewed based on advanced spectroscopic techniques, including reversed double-beam photoacoustic spectroscopy (RDB-PAS), thermally stimulated current (TSC), deep-level transient spectroscopy (DLTS), thermoluminescence (TL), electron paramagnetic resonance (EPR), and photoluminescence (PL), highlighting how each method describes trap energetics and populations under realistic operating conditions. Finally, case studies on the application of metal oxides and supported metals are discussed, as these are typical catalysts for the reaction mentioned above. This review highlights how oxygen vacancies (OVs), polarons, and metal–support interfacial sites act as robust electron reservoirs, lowering the barriers for CO2 activation and hydrogenation. By reframing thermocatalysts through the lens of ET chemistry, this review identifies ETs as actionable targets for the rational design of next-generation materials for CO2 hydrogenation and related high-temperature transformations.

This review addresses the crucial and emerging field of bacterial adaptation to antimicrobial nanomaterials, challenging prior assumptions that their multi-level action prevents the development of reduced bacterial sensitivity. It provides a comprehensive overview of experimentally induced adaptation mechanisms across various nanomaterials (e.g. AgNPs, ZnO) and bacterial species. Bacterial adaptations encompass genetic adaptations (e.g. efflux systems, mutagenesis), biomolecule production (e.g. flagellin, exopolysaccharides forming biofilms, protein coronas), and structural changes (e.g. altered shape, cell wall thickening, enhanced motility, membrane permeability changes). The described adaptation mechanisms to nanomaterials are compared with antibiotic resistance mechanisms, emphasizing common strategies such as efflux and envelope changes, but also unique adaptations specific to nanoparticles, such as aggregation and different roles of biomolecules. The review offers insights and emerging strategies for designing safer, more effective nano-antimicrobials, including membrane potential disruption, biofilm inhibition, and size modulation. It emphasizes the need for standardized evaluation methods and future research on cross-resistance.

CO2 hydrogenation to methanol is a favorable approach due to the vast potential usage of the produced methanol. Apart from copper-based catalysts, indium oxide-based catalysts have been reported as suitable candidates for CO2 transformation to a highly interesting product such as methanol. In this study, two different ZrO2 were used as support for laser-generated indium oxide combined with copper or nickel nanoparticles. The prepared catalysts demonstrated strong dependence in their catalytic activity, especially CO2 conversion and methanol selectivity, on the start form of ZrO2 support (monoclinic or mixed-phase), and on the metal promoter (copper or nickel). In particular, catalysts prepared with mixed-phase ZrO2 support showed up to 210% higher CO2 conversion compared to the monoclinic ZrO2-supported variants, which is unambiguously connected with the higher specific surface area of the used ZrO2 crystal modification. Concerning the influence of the metallic co-catalysts, the copper-based catalysts showed up to two times higher yield and selectivity towards methanol compared to those that used nickel oxides. In summary, this study shows the usability of laser-generated nanoparticles as catalysts for the catalyzed hydrogenation of CO2 to methanol, with certain advantages in relation to the transformation of the initial phase to the form of the active catalyst for the studied reaction.

This study reports on the performance of alumina-supported copper-based catalysts in the oxidative dehydrogenation of propane, with copper dispersed on two distinct commercial aluminium oxide supports made of micro- and nanosized alumina, respectively. The activity and selectivity of the two catalysts was investigated at temperatures between 250 and 550 °C. At a propane-to-O2 ratio of 1:1, Cu/nanoAl2O3 achieves propylene selectivity of 35–48% at low temperatures (250–300 °C), while Cu/Al2O3 only exhibits activity starting at 350 °C with about 40% propylene selectivity. Altering the propylene-to-oxygen ratio to 3:1 enhances selectivity towards propylene in both catalysts, up to about 64% on Cu/Al2O3 at temperatures of 250–350 °C. The switch to the mild oxidant CO2 boosts propylene selectivity to 100%. In case of Cu/nanoAl2O3, the rate of propylene formation doubles that of the obtained with O2 used as oxidant. While with CO2 the Cu/nanoAl2O3 catalyst retains 100% propylene selectivity up to 500 °C, on the less active Cu/Al2O3 cracking sets off already at 400 °C. The different size of copper particles in the two catalysts is seen as a primary factor determining the observed differences in the performance of the studied catalysts.

IntroductionThe growing prevalence of antibiotic-resistant bacteria highlights the urgent need for innovative antimicrobial materials. In this work, electrospun poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) fibers were functionalized with silver and gold nanoparticles (NPs) to combine high biocompatibility with strong antimicrobial activity.MethodsSilver and gold NPs were synthesized and characterized, confirming their anisotropic structure and high stability. Electrospinning produced uniform PHBV fibers, and surface modification with NPs via chitosan layer-by-layer ensured stable adhesion.ResultsAntibacterial tests demonstrated that, among all, silver-containing samples exhibited complete inhibition of both Escherichia coli and Staphylococcus aureus, confirming the strong bactericidal effect of AgNPs. Chitosan alone partially inhibited S. aureus and didn't affect E. coli due to differences in bacterial cell wall architecture. While chitosan modestly contributed to antibacterial activity, adding AgNPs was crucial for broad, effective antimicrobial action. All functionalized fibers exhibited excellent cytocompatibility with human keratinocytes (HaCaT cells), maintaining over 70% metabolic activity. Moreover, cytokine profiling revealed an anti-inflammatory effect, most pronounced in AgNP-functionalized PHBV samples, and upregulation of human β-defensin 2 (HBD-2) in AuNP-functionalized samples, suggesting additional indirect antibacterial mechanisms.DiscussionThe developed PHBV-based fibers functionalized with metallic NPs demonstrated an excellent balance of safety, cytocompatibility, and antibacterial performance, making them promising candidates for biomedical applications that require both inflammation control and antimicrobial protection.

The hematite phase decorated with iron-doped cerium oxide nanoparticles (F@FC) was precipitated from cerium and iron oxalate intermediate products. The photocatalytic composite of graphitic carbon nitride (gCN) and F@FC was prepared by a simple method involving mixing the two components, followed by thermal treatment at 400 °C. According to electron microscopy, F@FC is composed of a submicron iron oxide (hematite) phase decorated with iron-doped cerium oxide nanoparticles deposited on gCN substrate. A hierarchically structured composite was observed instead of a simple mechanical mixture of α-Fe2O3, Fe-CeO2, and gCN. To observe two types of degradation activity, photocatalytic and Photo-Fenton degradation activity, Rhodamine B (RhB) was applied as the model water pollutant. The influence of the amount of photocatalyst, the RhB concentration, the presence of cations and anions, the pH, and the effect of e-, h+, •OH, and •O2- scavenging reactants were studied. The Photo-Fenton degradation exhibited high efficiency across the entire tested pH range, whereas photocatalytic degradation showed comparable activity only at acidic pH. The F@FC-gCN composite catalyst exhibited a high degree of recyclability. The degradation pathways of photocatalytic and Photo-Fenton reactions were suggested by HPLC-MS analysis of the reaction products. A notable finding of this study was the observation that the green-yellow, fluorescent intermediate Rhodamine 110 was formed during the photocatalytic degradation of RhB. However, the high reactivity of the generated •OH radicals during Photo-Fenton degradation has been demonstrated to inhibit the formation of intermediate Rhodamine 110.

The synthesis, in particular the industrial production, of pharmaceuticals requires a broad arsenal of synthetic reactions capable of selectively forming specific structural motifs and assembling smaller building blocks into complex molecules. The Chan-Evans-Lam cross-coupling reaction, which forms a bond between a N-nucleophile and an aryl group from a boronic acid, catalysed by copper salts, is a typical example of this synthetic route. Considering the toxicity of copper and the stringent regulatory limits for its residues in final pharmaceutical products, a heterogeneous catalytic approach offers a viable alternative for this transformation. In this work, we present a simply and reproducibly synthesized catalyst based on copper nanoparticles supported on reduced graphene oxide (Cu-rGO), with high efficiency in a model Chan-Lam reaction involving benzimidazole and aniline derivatives with substituted boronic acids.

BackgroundMetal nanoparticles are increasingly explored in biomedical and technological applications, yet their cytotoxicity remains difficult to interpret due to the strong influence of multiple physicochemical parameters. Differences in synthesis protocols, particle size, morphology, and surface properties across studies often hinder direct comparison of toxicological outcomes and limit the ability to attribute observed effects to the chemical composition of the nanoparticle core.MethodsIn this study, silver (Ag), copper (Cu), and gold (Au) NPs were synthesized under identical conditions to control for size, shape, and surface charge, thereby isolating the effect of chemical composition. The NPs (8–9 nm, spherical, zeta potential ∼ –21 mV) were evaluated in NIH 3T3 fibroblasts using MTT viability assays, reactive oxygen species (ROS) detection, mitochondrial membrane potential analysis, apoptosis quantification, and comet assays.ResultsAg NPs showed the highest toxicity (IC50 = 11.9 mg·L-1), followed by Cu NPs (51.6 mg·L-1), while Au NPs were the least toxic (228.2 mg·L-1). Mechanistic data revealed that Ag NPs induced severe oxidative stress and mitochondrial dysfunction, leading to apoptosis at sublethal concentrations and necrosis at higher doses. Cu NPs triggered strong ROS generation and apoptotic signaling. Au NPs showed minimal toxicity, with weak apoptotic effects only at the highest concentrations. None of the tested NPs caused significant DNA damage. Notably, cytotoxicity correlated with increased necrosis at higher doses and apoptosis at lower concentrations, indicating dose- and composition-dependent cell death mechanisms. While reactive oxygen species contributed to toxicity, the small size (∼8–10 nm), spherical morphology, and absence of surface modification enhanced cellular uptake and cytotoxic potential.ConclusionOur results provide clear evidence that, for controlled nanoparticle properties, the toxicity hierarchy primarily reflects intrinsic chemical identity. These findings underscore the importance of separating nanoparticle composition from other particle-related artifacts, thereby supporting the rational design of safer biomedical nanomaterials through the controlled adjustment of size, surface chemistry, and metal composition.

Gadolinium in the form of complex compounds is used as a contrast agent in medicine diagnostic for magnetic resonance imaging. Gadolinium-based contrast agents are divided into linear and macrocyclic substances in ionic or nonionic forms. Gd3+ toxic ions can be replaced from these compounds by cations such as Fe3+ and Cu2+. Gadolinium inhibits the activity of some enzymes dependent on calcium. The macrocyclic compound binds Gd3+ more strongly than the linear complexes. The influence of Fe3+ and Cu2+ ions on the displacement of Gd3+ from the macrocyclic MRI contrast agent Gadovist (Gadobutrol) was studied. For comparison with Gadovist transmetallation of Gd3+ ions, also the removal experiments of Gd3+ ions themselves from the water environment were performed. For this purpose, sea sand modified by 3-aminopropyltriethoxysilane was used. These molecules are capable to capture Gd3+ ions, as was confirmed by ICP-MS measurements. The prepared samples of modified sea sand were characterized by FTIR and TGA measurements. In the case of Gd3+ ions alone, a significant decrease in Gd3+ ions concentration was observed when using the modified sea sand. Depending on the preparation, method used (change of temperature and mixing time, 2 h at 60 degrees C, 20 h at 20 degrees C), different properties were observed regarding the morphology of the sea sand particles and also the amount of APTES molecules bound to the sea sand surface. The efficiency of capture (elimination) of Gd3+ ions in the case of tap water was almost 90%-100% in the range of pH values between 5 and 9. Initial concentration of Gd3+ ions was 0.1 mg center dot L-1. The experiments carried out for Gadovist proved that almost no release of Gd3+ ions to the water environment was observed when testing the influence of two different weight concentrations of Fe3+ and Cu2+, 1 or 10 mg & centerdot;L-1 for possible displacement Gd3+ ions (0.1 mg & centerdot;L-1) from the Gadovist and release to the water environment which was confirmed using ICP-MS measurements and determined concentration of Gd3+ ions was at the level 1 & micro;g & centerdot;L-1.

Energy-saving and cost-efficient reaction routes to prepare highly active catalysts for CO2 hydrogenation or solid oxide fuel cells (SOFCs) are enormously important. In this paper, we report a detailed study of a dichromate salt of [Fe(urea)6]3+, a member of the [M(urea)6]3+ complex family (M = Fe, Al, Mn, Cr, V, or Ti) with oxidizing anions, which is a promising precursor of a Cr-rich mixed chromium iron oxide catalyst prepared at a low temperature in the solid phase. The single-crystal X-ray structure, various (infrared, ultraviolet-visible, and Raman) spectroscopic studies, and thermal analysis (differential scanning calorimetry and thermogravimetric analysis/mass spectrometry) of [hexakis(urea-O)iron(III)] dichromate {[Fe(urea-O)6]2(Cr2O7)3} and its decomposition products confirmed the presence of a quasi-intramolecular redox reaction between the urea ligands and dichromate anions. The redox reactions result in various mixed Cr-Fe oxides with amorphous structure, whereas above 550 degrees C, the crystal structure and composition of the final products depend on the atmosphere during the thermal decomposition. The iron-chromium mixed oxides are potential catalysts in CO2 hydrogenation that afford CO, CH4, C2H6, and C3H8. Furthermore, our Mossbauer spectroscopy studies show a possible electron hopping between the FeII and FeIII ions at the tetrahedral sites of the spinel structure, which suggests that the formed chromite is also a potential SOFC material. Our study also demonstrates that hexaureairon(III) dichromate is a selective oxidation agent of sulfur-containing organic compounds.

This comprehensive review explores silica aerogels and their application in environmental remediation. Due to rapid growth in the consumption of energy and water resources, the purification of contaminated resources for use by humankind should be considered important. The primary objectives of this review are to assess the evolving landscape of silica aerogels, their preparation, and drying techniques, and to discuss the main findings from a wide range of empirical studies and theoretical perspectives. Based on a significant amount of research, this review provides information about aerogels’ capabilities as an adsorbent and catalyst. The analysis spans a variety of contexts for the generation of hydrogen and the degradation of the dyes employed in industry, showing better performance in environmental remediation. The implications of this review point to the need for well-informed policies, innovative synthesis strategies, and ongoing research to harness the full potential for environmental management.

The conversion of carbon dioxide into fuels and fine chemicals is a highly desirable route for mitigating flue gas emissions. However, achieving selectivity toward olefins remains challenging and typically requires high temperatures and pressures. Herein, we address this challenge using 12 nm copper nanoparticles supported on FeOx micro-rods, which promote the selective hydrogenation of CO2 to light olefins (C2-C4) under atmospheric pressure. This catalyst achieves up to 27% conversion and 52% selectivity toward C2-C4 olefins, along with the production of C2-C4 paraffins, C5+ hydrocarbons (with all C1+ products totalling to up to about 75%), and methane, while suppressing CO formation to just 1% at 340 °C. The enhanced performance of the Cu/FeOx pre-catalyst is attributed to the efficient in situ generation of iron carbides (Fe5C2) in the presence of copper nanoparticles, as confirmed by ex situ XRD analysis. Copper facilitates the reduction of FeOx to form Fe5C2, a crucial intermediate for shifting the reaction equilibrium toward higher hydrocarbons. The hydrogenation of CO2 to higher hydrocarbons proceeds through the reverse water-gas shift reaction coupled with Fischer-Tropsch synthesis.

The crucial factor for sufficient analysis by surface-enhanced Raman spectroscopy is the preparation of an effective SERS substrate with a surface of appropriate optical properties. This work focuses on the modification of surfaces of Al2O3 and cellulose impregnated by polyethyleneimine to increase the deposition effectiveness, size, and morphological characteristics of the deposited silver particles. Modifications of substrates were done by polydopamine layer formation on substrate surfaces or by surface activation through immersion in SnCl2 solution. The silver particle layers were done by deposition from a liquid phase using ultrasound-assisted reduction of silver ammonia complex ([Ag(NH3)2]+) by maltose or glucose which served as reductants. Prepared layers were in some cases subsequently recrystallized by NaCl solution which led to formation of the larger silver particles or aggregates. The morphologies of the prepared layers were characterized by SEM. The SERS efficiency of the presented substrates was tested through SERS measurements of 10-5 M adenine solution using lasers of 532 nm and 780 nm excitation wavelengths. The influence of substrate surface modification and re-crystallization of the silver particles on SERS efficiency was evaluated by enhancement factor calculations. Their values reached up to 1.4.106 for 780 nm and 8.1.105 for 532 nm lasers.

Silver nanoparticles (Ag NPs) significantly enhance the antibacterial activity of antibiotics and even restore their effect against resistant strains, making them a promising option for overcoming bacterial resistance to antibiotics. However, the exact mechanism of their synergistic effect with antibiotics at the cellular level has not been elucidated. In this work, we synthesised rhodamine-labelled Ag NPs and described, for the first time, the multi-level non-specific mechanism of the synergistic antibacterial effect of fluorescently labelled Ag NPs and a fluorescent vancomycin conjugate against vancomycin-resistant enterococci using high-resolution fluorescence microscopy. The multi-level mechanism of the synergistic effect of Ag NPs and vancomycin is mainly based on the disruption of the strength and integrity of the cell wall, which becomes unstable, loses strength and subsequently disintegrates due to the oxidative stress caused by Ag NPs and the residual effect of vancomycin. In addition, Ag NPs penetrate the bacterial cell and deform the bacterial DNA, which also significantly increases the synergistic antibacterial effect. This work represents an advance in understanding the mechanism of synergistic effect of Ag NPs with antibiotics against resistant bacteria, an important finding for a potential approach to effectively combat the unsolved problem of increasing resistance of pathogenic bacteria to traditional antibiotics.

Nickel and nickel oxide are widely used as heterogeneous catalysts in various processes involving the hydrogenation or reduction of organic compounds, and also as excellent methanation catalysts in the hydrogenation of CO2. As heterogeneous catalysis is a surface-dependent process, nickel compounds in the form of microparticles (MPs), and particularly nanoparticles (NPs), improve the catalytic activity of Ni-based catalysts due to their high specific surface area. Solvothermal synthesis, which has so far been neglected for the synthesis of Ni-based methanation catalysts, was used in this study to synthesize nickel and nickel oxide MPs and NPs with a narrow size distribution. Solvothermal synthesis allows for the control of both the chemical composition of the resulting Ni catalysts and their physical structure by simply changing the reaction conditions (solvent, temperature, or concentration of reactants). Only non-toxic substances were used for synthesis in this study, meaning that the whole synthesis process can be described as environmentally friendly. Solvothermally prepared Ni compounds were subsequently transformed into nickel oxide by means of high-temperature decomposition, and all of the prepared Ni-based compounds were tested as catalysts for CO2 methanation. The best catalysts prepared in this study exhibited a CO2 conversion rate of nearly 95% and a selectivity for methane close to 100%, which represent thermodynamic limits for this reaction at the used temperature. These results are commonly achieved with much more complex catalytic composites containing precious metals, while here we worked with pure nickel and its oxides, in the form of micro- or nanoparticles, only.

Selenium nanoparticles (SeNPs) have recently attracted attention for their antimicrobial and anticancer activities. Nevertheless, their use remains limited due to stability issues. The objective of this study is to investigate the impact of different reaction conditions (including the reducing and stabilizing agents, as well as reaction temperature) on the water dispersion characteristics, stability, and biological activity of SeNPs. The particle characteristics were controlled using sodium borohydride as a strong reducing agent and ascorbic acid as a mild agent. The impact of different stabilizers, namely sodium oleate, quercetin, gelatine, poly(ethyleneimine), and poly(diallyldimethyl-ammonium chloride), was investigated on both particle stability and biological activity. Several destabilizing processes occurred, one of which was continuous reduction to the final Se(-II) oxidation state, which was observed in both synthetic approaches, with using sodium borohydride or ascorbic acid as reducing agents. Non-stabilized SeNP dispersions were stable for a maximum of two weeks, while most stabilized SeNP dispersions remained stable for at least two months, and some remained stable for as long as six months. The antibacterial activity had strong effects, particularly against Gram-positive bacteria, and simultaneously low cytotoxicity against mammalian cells. SeNPs exhibited significant antibacterial efficacy, particularly against Staphylococcus aureus, including methicillin-resistant Staphylococcus aureus strains, even at concentrations as low as 1 mg L-1. SeNPs synthesized utilizing sodium borohydride demonstrate minimal cytotoxicity (EC50 > 100 mg L-1). Interestingly, SeNPs reduced by ascorbic acid demonstrated higher cytotoxicity (EC50 6.8 mg L-1) against the NIH/3T3 cell line. This effect is likely due to the combined cytotoxic effect of SeNPs and ascorbic acid acting as a pro-oxidant at high concentrations.

ABSTRACT To investigate the possibilities of preparing planar surface‐enhanced Raman spectroscopy (SERS) substrates, several types of cellulose‐based commercially available thin‐layer‐chromatography (TLC) layers, microcrystalline cellulose, diethylaminoethyl cellulose and polyethyleneimine impregnated cellulose, were studied as supporting substrates. There is a worldwide need for making various processes, including chemical synthesis, greener. Therefore, cellulose was chosen as the base for SERS substrates for its economic and environmentally friendly characteristics. For the SERS substrates preparation, Tollens' process was used, and as reducing substances, maltose and glucose were used. All the prepared samples were able to detect 10 −5 M adenine solution (using 780‐nm laser wavelength), which was chosen as the model analyte to evaluate their SERS efficiency. The highest SERS response was achieved with the sample prepared on microcrystalline cellulose using maltose as the reducing agent. This substrate was subsequently used for determination of adenine limit of detection, with the value of LOD = 10 −7 M. Calculated analytical enhancements factor reached up to 10 8 . Moreover, TLC layers represent a semi‐flexible substrate, which can be beneficial for many future applications.

Medical research is at the forefront of addressing pressing global challenges, including preventing and treating cardiovascular, autoimmune, and oncological diseases, neurodegenerative disorders, and the growing resistance of pathogens to antibiotics. Understanding the molecular mechanisms underlying these diseases, using advanced medical approaches and cutting-edge technologies, structure-based drug design, and personalized medicine, is critical for developing effective therapies, specifically anticancer treatments. Background/Objectives: One of the key drivers of cancer at the cellular level is the abnormal activity of protein enzymes, specifically serine, threonine, or tyrosine residues, through a process known as phosphorylation. While tyrosine kinase-mediated phosphorylation constitutes a minor fraction of total cellular phosphorylation, its dysregulation is critically linked to carcinogenesis and tumor progression. Methods: Small-molecule inhibitors, such as imatinib or erlotinib, are designed to halt this process, restoring cellular equilibrium and offering targeted therapeutic approaches. However, challenges persist, including frequent drug resistance and severe side effects associated with these therapies. Nanomedicine offers a transformative potential to overcome these limitations. Results: By leveraging the unique properties of nanomaterials, it is possible to achieve precise drug delivery, enhance accumulation at target sites, and improve therapeutic efficacy. Examples include nanoparticle-based delivery systems for TKIs and the combination of nanomaterials with photothermal or photodynamic therapies to enhance treatment effectiveness. Combining nanomedicine with traditional treatments holds promise and perspective for synergistic and more effective cancer management. Conclusions: This review delves into recent advances in understanding tyrosine kinase activity, the mechanisms of their inhibition, and the innovative integration of nanomedicine to revolutionize cancer treatment strategies.