Search Results (788)

The increasing environmental presence of metal oxide nanoparticles (NMOPs) raises concerns regarding their influence on biological wastewater treatment. This study comparatively evaluates the structural and biological effects of zinc oxide (ZnO-NPs) and titanium dioxide (TiO₂-NPs) nanoparticles on activated sludge from a wastewater treatment plant. Experimental exposure covered nanoparticle concentrations of 0.05–0.3 g/L and contact times up to 180 min, with analysis of enzymatic activity (dehydrogenase activity, TTC-SA method), sludge settleability, and particle size distribution. Inhibition of microbial metabolic activity was observed in a clear dose- and time-dependent manner, with ZnO-NPs showing stronger toxicity than TiO₂-NPs. At the highest dose (0.3 g/L), enzymatic activity nearly disappeared after 90 min (0.04 µg TPF/mg MLSS). Both nanoparticles caused floc fragmentation, decreased sludge volume index (SVI), and increased the proportion of ultrafine particles (<0.3 µm). ZnO-NPs induced more severe destabilization, while TiO₂-NPs showed partial re-aggregation of suspended particles at higher concentrations. Additionally, particle size distribution in the supernatant was analyzed, revealing distinct aggregation and fragmentation patterns for ZnO- and TiO₂-NPs. These structural and functional alterations suggest potential risks for treatment efficiency, including reduced nutrient removal and impaired sludge settleability. The study provides a comparative contribution to understanding toxicity mechanisms of ZnO- and TiO₂-NPs and emphasizes the need to monitor NMOPs in wastewater and to develop mitigation strategies to ensure stable plant operation Full article

Titanium dioxide nanotubes (TiO₂ NTs) decorated with lead sulfide nanoparticles (PbS NPs) were synthesized using the Successive Ionic Layer Adsorption and Reaction (SILAR) method at different number (n) of cycles (where n = 3, 5, and 8) and evaluated for tetracycline (TC) photodegradation under UV light. PbS NPs/TiO₂ NTs heterojunctions prepared with 5 SILAR cycles showed optimal photocatalytic activity. Also, under optimized conditions, pure TiO₂ NTs achieved complete TC photodegradation (99%) within 5 h under UV irradiation, with a proposed degradation mechanism based on holes (h⁺) and hydroxyl radicals (•OH) as dominant reactive species. Full article

Secondary liver injury (SLI) is the most common complication in the development of inflammatory bowel disease (IBD), and it is susceptible to environmental factors, including diet patterns. As a food-brightening agent, titanium dioxide nanoparticles (TiO₂ NPs) are inevitably consumed by IBD patients. Currently, there are a few studies on TiO₂ NPs exposure to SLI in colitis mice. In this study, a SLI model was built using dextran sodium sulfate (DSS) free-drinking for 7 days after pre-exposure to TiO₂ NPs. The changes in the pathological results and liver function indicators suggested that high-dose TiO₂ NPs only exhibited a slight injury in the liver. With further analysis, we found that pre-exposure to high-dose TiO₂ NPs in mice with SLI led to an increase in intestinal permeability and hepatic LPS content, along with increased inflammatory cytokines and an anti-oxidative system imbalance. Subsequently, accumulated LPS and ROS overproduction activated the NOD-like receptor family pyrin-containing 3 (NLRP3) inflammasome, inducing hepatic cell pyroptosis. To provide compelling evidence, NLRP3 gene-deficient mice were used, and the results showed that the absence of NLRP3 improved liver function, alleviated hepatic inflammation, and reduced hepatic oxidative injury in SLI mice with TiO₂ NPs exposure. In summary, these results confirmed the critical role of the NLRP3 inflammasome in the TiO₂ NP-aggravated progression of SLI. Our study provided a comprehensive evaluation of foodborne nanoparticles on IBD complications, hoping that more studies can focus on IBD complications affected by environmental factors. Full article

Metal oxide nanoparticles, such as ZnONPs and TiO₂NPs, are increasingly applied in various industries. However, their effects on photosynthetic microorganisms at environmentally relevant concentrations remain poorly understood. This study evaluated the impact of ZnONPs and TiO₂NPs, at concentrations ranging from 0.1 to 30 mg/L, on the cyanobacterium Nostoc linckia (strain CNMN-CB-03), a species recognized for its adaptability and biotechnological potential. The nanoparticles were added to controlled cultures, and changes in biomass composition and pigment content were assessed using spectrophotometric assays. Both nanoparticle types significantly affected the physiological and biochemical profile of Nostoc linckia. Low concentrations of ZnONPs stimulated the accumulation of biomass, chlorophyll, carotenoids, and lipids, while higher doses caused a reduction in phycocyanin and in total phycobiliproteins content. TiO₂NPs consistently promoted biomass growth across all tested concentrations, with decrease in carotenoids and total phycobiliproteins observed at the highest concentrations. For both nanoparticle types, malondialdehyde (MDA) levels decreased compared to the control, indicating reduced oxidative stress and effective cellular adaptation. The results highlight the remarkable resilience and metabolic flexibility of Nostoc linckia in the presence of nanoparticles, supporting its potential as a biotechnological platform for the sustainable production of valuable metabolites under controlled stress conditions. Full article

Salinity is a significant challenge that limits agricultural productivity worldwide. This study examined the use of nanoparticles to improve the growth and development of Solanaceae crops under salinity stress. Specifically, titanium dioxide (TiO₂NPs), copper oxide (CuONPs), and zinc oxide (ZnONPs) were applied at 750, 1250, and 1500 mg/kg per seed, respectively, to assess their effects on seed germination and growth of tomato, eggplant, and pepper plants. Results showed that tomato plants under salinity stress performed best with CuONPs, which improved key traits. The combination of salinity and TiO₂NPs reduced flower abortion and increased seed yield and 1000-Seed weight. In eggplants, CuONPs and ZnONPs, both individually and in combination with salinity, enhanced plant characteristics, with CuONPs showing particularly strong effects. Control plants consistently recorded the lowest values across traits. For peppers, ZnONPs applied individually most effectively improved growth traits, while CuONPs reduced flower abortion and enhanced seed and germination rates. However, salinity stress itself severely reduced pepper growth parameters. The findings highlight the potential of nanoparticle applications to mitigate salinity stress, enhance growth performance, and support sustainable crop production in tomatoes, eggplants, and peppers, offering practical solutions for salinity-affected agriculture. Full article

Lilium species produce some of the most commercially valuable ornamental flowers in the world, characterized by their attractiveness and high demand in cut flower markets. However, it is necessary to strengthen the competitiveness of this sector in the global market. Due to strong competition from international producers and an increasingly demanding market regarding quality, shelf life, and sustainability, alternatives are being sought to counteract the use of conventional agrochemicals. The use of nanoparticles has emerged as a promising strategy in ornamental horticulture due to their ability to enhance plant growth, improve stress tolerance, and stimulate physiological processes, ultimately contributing to higher quality and productivity. The hypothesis of this research is that the foliar application of selenium and titanium dioxide nanoparticles during the vegetative growth and flowering stages significantly enhances the growth, development, and flowering of Lilium plants when compared with untreated plants. Therefore, the physiological effects of SeNPs and TiO₂NPs applied via foliar application in two concentrations (SeNPsD1, SeNPsD2, TiNPsD1, and TiNPsD2) were evaluated against absolute control. The treatments were applied in two phenological stages (vegetative and reproductive development), and their effects on vegetative and reproductive variables in Lilium plants were evaluated from 120 to 270 days after sowing. The surface of seeds obtained from SeNPsD1-treated plants was further analyzed via scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS). The results demonstrate that the application of SeNPs generated variable effects depending on the phenological stage. In the vegetative stage (46 DAS), SeNPsD2 increased the number of leaves by 118%, while SeNPsD1 increased the fresh weight of leaves by 110%. Regarding ovaries, the application of SeNPsD2 resulted in a 276% increase in fresh weight and a 230% increase in dry weight, while SeNPsD1 achieved an increase of 164% in fresh weight. Furthermore, at this stage, SeNPsD2 promoted a 223% increase in the number of bulbils, a 240% increase in fresh weight, and a 199% increase in dry weight. In the reproductive stage (69 DAS), SeNPsD1 increased the leaf fresh weight by 1% and yielded a 107% increase in the number of ovaries, in addition to 307% and 328% increases in their fresh and dry weights, respectively. In the same stage, SeNPsD2 increased the fresh ovary weight by 153%, compared with the control. Finally, capsule formation was observed only under the SeNPsD1 treatment. Meanwhile, TiO₂NPs had an effect on the number of buds and the number of open buds: the number of buds increased by 115% with TiNPsD1 (69 DAS) and the number of open buds increased by 104% (46 DAS) with TiNPsD1; in the reproductive stage, the number increased by 115% with TiNPsD1 compared with the control. In the seed capsules of plants treated with selenium nanoparticles (SeNPsD1), although no surface selenium was detected via EDS, elements that had possibly been physiologically redistributed were identified, including iron (Fe), silicon (Si), and aluminum (Al). These findings confirm the hypothesis of this research, demonstrating that the foliar application of SeNPs and TiO₂NPs to Lilium plants during the vegetative and reproductive stages significantly improves their vegetative growth, reproductive development, and floral quality under controlled conditions. This work presents the first comparative evidence regarding the effects of SeNPs and TiO₂NPs on the vegetative and reproductive characteristics of Lilium Sunny Oriental, providing unprecedented information for the use of nanotechnology in ornamental horticulture. The findings confirm the potential use of nanoparticles as agents to optimize the productivity and commercial quality of ornamental flowers in highly competitive markets. Full article

In this study, highly ordered titanium dioxide nanotubes (TiO₂-NTs) have been synthesized using the electrochemical anodization procedure. Subsequently, the TiO₂-NTs were successfully decorated with PbS nanoparticles (NPs) using the pulsed KrF-laser deposition (PLD) technique under vacuum and under different Helium background pressures (P_He) ranging from 50 to 400 mTorr. The prepared samples (PbS-NPs/TiO₂-NTs) were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), and UV–Vis and photoluminescence spectroscopies. XRD analyses confirmed that all TiO₂-NTs crystallized in the anatase phase, while the PbS-NPs crystallized in the cfc lattice. The average crystallite size of the (200) crystallites was found to increase from 21 to 33 nm when the pressure of helium (PHe) was raised from vacuum to 200 mTorr and then dropped back to ~22 nm at P_He = 400 mTorr. Interestingly, the photoluminescence intensity of the PbS-NPs/TiO₂-NTs samples was found to start diminishing for P_He ≥ 200 mTorr, indicating a lesser recombination rate of the photogenerated carriers, which also corresponded to a better photocatalytic degradation of the Amido Black (AB) dye. Indeed, the PbS-NPs/TiO₂-NTs samples processed at P_He = 200 and 300 mTorr were found to exhibit the highest photocatalytic degradation efficiency towards AB with a kinetic constant 130% higher than that of bare TiO₂-NTs. The PbS-NPs/TiO₂-NTs photocatalyst samples processed under P_He = 200 or 300 mTorr were shown to remove 98% of AB within 180 min under UV light illumination. Full article

Endocytic uptake and lysosomal localization are suggested to be the key mechanisms underlying the toxicity of metal oxide nanoparticles (MONPs), with dissolution in the acidic milieu driving the response. In this study, we aimed to investigate if MONPs of varying solubility are similarly sequestered intracellularly, including in lysosomes and the role of the acidic lysosomal milieu on toxicity induced by copper oxide (CuO) nanoparticles (NPs), nickel oxide (NiO) NPs, aluminum oxide (Al₂O₃) NPs, and titanium dioxide (TiO₂) NPs of varying solubility in FE1 lung epithelial cells. Mitsui-7 multi-walled carbon nanotubes (MWCNTs) served as contrasts against particles. Enhanced darkfield hyperspectral imaging (EDF-HSI) with fluorescence microscopy was used to determine their potential association with lysosomes. The v-ATPase inhibitor Bafilomycin A1 (BaFA1) was used to assess the role of lysosomal acidification on toxicity. The results showed co-localization of all MONPs with lysosomes, with insoluble TiO₂ NPs showing the greatest co-localization. However, only acute toxicity induced by soluble CuO NPs was affected by the presence of BaFA1, showing a 14% improvement in relative survival. In addition, all MONPs were found to be associated with large actin aggregates; however, treatment with insoluble TiO₂ NPs, but not soluble CuO NPs, impaired the organization of F-actin and α-tubulin. These results indicate that MONPs are sequestered similarly intracellularly; however, the nature or magnitude of their toxicity is not similarly impacted by it. Future studies involving a broader variety of NPs are needed to fully understand the role of differential sequestration of NPs on cellular toxicity. Full article

Soybean is rich in protein and functional ingredients, which are in high demand as a food material; however, it is vulnerable to environmental stress. On the other hand, the application of chemically synthesized titanium oxide nanoparticles (TiO₂ NPs) promoted soybean growth even under salt stress. To further enhance the growth-promoting effect of TiO₂ NPs on soybeans, they were biologically synthesized using orange peel extract. Root elongation of soybeans suppressed by salt stress was restored to the control level by treatment with green synthesized (GS)-TiO₂ NPs. To clarify the promoting mechanism in soybean of GS-TiO₂ NPs under salt stress, immunoblot analysis was performed. The abundance of vacuolar H⁺-ATPase decreased in roots by salt stress was recovered with GS-TiO₂ NPs. In contrast, the abundance of glutathione reductase increased in roots and hypocotyls by salt stress was recovered with GS-TiO₂ NPs. Furthermore, hydrogen peroxide production increased in roots with salt stress that was restored by treatment with GS-TiO₂ NPs. These results suggest that GS-TiO₂ NPs may restore soybean growth by detoxifying hydrogen peroxide, which increases under salt stress, with upregulating reactive oxygen species scavenging systems. Full article

This work focused on the photocatalytic performance enhancement of titanium dioxide (TiO₂) nanotubes decorated by gold nanoparticles. The surface of the nanotubes synthesized using the anodization technique was modified with subsequent deposition of gold nanoparticles (Au-NPs) via electrophoretic deposition. The impact of electrophoretically deposited gold nanoparticles (Au-NPs) on TiO₂ nanotubes, with varying deposition times (5 min, 8 min and 12 min), was investigated in the degradation of amido black (AB) dye. The morphological analysis using scanning electron microscopy (SEM, TESCAN VEGA3, TESCAN Orsay Holding, Brno, Czech Republic) and transmission electron microscopy (TEM, JEM—100CX2, JEOL Japan). revealed a well-organized nanotubular structure of TiO₂, with a wall thickness of 25 nm and an internal diameter of 75 nm. Optical study, including photoluminescence and diffuse reflectance spectroscopy, provided evidence of charge transfer between the Au-NPs and the TiO₂-NTs. Furthermore, the photocatalytic measurements showed that the enhanced photocatalytic activity of the TiO₂-NTs resulted from successful Au deposition onto their surface, surpassing that of the pure sample. This improvement is attributed to the higher work function of gold nanoparticles, which effectively promoted the separation of photogenerated electron–hole pairs. The sample Au-NPs/TiO₂-NTs with a deposition time of 5 min exhibited the best photocatalytic efficiency, achieving an 85% degradation rate after 270 min under UV irradiation. Moreover, the enhancement obtained was also attributed to the plasmonic effect induced by Au-NPs. Kinetic investigations revealed that the photocatalytic reaction followed apparent first-order kinetics, highlighting the efficiency of Au-NPs/TiO₂-NTs as a photocatalyst for dye degradation. Full article

The utility of nanostructured TiO₂ in the degradation of organic compounds and the disinfection of pathogenic microorganisms represents an important endeavor in photocatalysis. However, the low photocatalytic efficiency of TiO₂ remains challenging. Herein, we report a robust photocatalytic route to benzene removal rendered by enhancing its adsorption capacity via rationally designed mesoporous SiO₂-coated TiO₂ colloids. Specifically, amorphous, mesoporous SiO₂-coated TiO₂ nanoparticles (denoted T@S NPs) are produced via a precipitation-gel-hydrothermal approach, possessing an increased specific surface area over pristine TiO₂ NPs for improved adsorption of benzene. Notably, under UV irradiation, the degradation rate of benzene by T@S NPs reaches 89% within 30 min, representing a 3.1-fold increase over that achieved by pristine TiO₂. Moreover, a 99.5% degradation rate within 60 min is achieved and maintains a stable photocatalytic activity over five cycles. Surface coating of TiO₂ with amorphous SiO₂ imparts the T@S composite NPs nearly neutral characteristic due to the formation of Ti-O-Si bonds, while manifesting enhanced light harvesting, excellent stability, adhesion, and photocatalytic bacteriostatic effects. Our study underscores the potential of T@S composites for practical applications in photocatalysis over pristine counterparts. Full article

Acanthopanax senticosus is an essential medicinal herb in traditional Chinese medicine, with its pharmacological properties largely attributed to bioactive flavonoids. The types and amounts of these flavonoids act as vital quality markers for both the raw materials and the resultant products. In this work, we introduce a TiO₂@AgNP nanocomposite designed as a surface-enhanced Raman scattering (SERS) sensor aimed at the preliminary quantification and identification of flavonoids. This is achieved by leveraging the effective molecular adsorption properties of TiO₂ alongside the ‘hot spots’ generated by AgNPs. By optimizing SERS performance through adjustment of the molar ratio between TiO₂ and Ag, we can quantitatively evaluate four flavonoids—luteolin, kaempferol, quercetin, and rutin—with low detection concentrations of 10⁻⁶ M, 10⁻⁵ M, 5 × 10⁻⁶ M, and 10⁻⁶ M, respectively. Additionally, we observe a nearly linear relationship between the SERS signals and the flavonoid concentrations, allowing for dual or multiplex analysis of these compounds. Furthermore, we successfully differentiated Acanthopanax senticosus samples from six different geographical regions in China based on the detection of significant flavonoid constituents. This serves as a proof of concept for practical applications that can enhance the identification and distinction of traditional Chinese medicine, as well as assess quality and medicinal efficacy. Full article

Photocatalysis offers a cost-effective and eco-friendly approach for environmental remediation, yet traditional powdered photocatalysts suffer from poor recyclability and separation challenges. To address these limitations, we developed a recyclable carbon fiber-supported composite photocatalyst (CC/TiO₂ NRs@MoS₂ NPs) featuring a three-dimensional hierarchical core–shell architecture. This structure comprises a TiO₂ seed layer, vertically aligned TiO₂ nanorod arrays as the core, and a MoS₂ nanoparticle shell, fabricated via sequential deposition. Under simulated solar irradiation, the TiO₂@MoS₂ heterojunction exhibited significantly enhanced uranium adsorption capacity, achieving a remarkable 97.3% photocatalytic removal efficiency within 2 h. At an initial uranium concentration of 200 ppm, the material demonstrated an exceptional extraction capacity of 976.7 mg g⁻¹, outperforming most reported photocatalysts. These findings highlight the potential of this 3D core–shell design for efficient uranium recovery and environmental purification applications. Full article

Nanofertilizers (NFs) and engineered nanoparticles (NPs) are increasingly used in agriculture, yet their environmental safety remains poorly understood. This study evaluated the comparative phytotoxicity of zinc oxide (ZnO), titanium dioxide (TiO₂), and clinoptilolite nanoparticles, three commercial nanofertilizers, and potassium dichromate (K₂Cr₂O₇) using Lactuca sativa seeds under adapted OECD-208 protocol conditions. Seeds were exposed to varying concentrations of each xenobiotic material (0.5–3% for NFs; 10–50% for NPs), with systematic assessment of seedling survival, root and hypocotyl length, dry biomass, germination index (GI), and median effective concentration (EC₅₀) values. Nanofertilizers demonstrated significantly greater phytotoxicity than engineered nanoparticles despite lower application concentrations. The toxicity ranking was established as NF1 > NF3 > NF2 > NM2 > NM1 > NM3, with NF1 being most toxic (EC₅₀ = 1.2%). Nanofertilizers caused 45–78% reductions in root length and 30–65% decreases in dry biomass compared with controls. GI values dropped to ≤70% in NF1 and NF3 treatments, indicating concentration-dependent growth inhibition. While nanofertilizers offer agricultural benefits, their elevated phytotoxicity compared with conventional nanoparticles necessitates rigorous pre-application safety assessment. These findings emphasize the critical need for standardized evaluation protocols incorporating both physiological and ecotoxicological endpoints to ensure safe xenobiotic nanomaterial deployment in agricultural systems. Full article

Ecotribology focuses on both saving energy resources and reducing environmental pollution. Considering environmental concerns, water-based nanolubricants have gained significant attention over conventional oil-based ones. Non-ecotoxic and highly environmentally friendly nanoadditives were chosen for nanolubricant synthesis, especially considering their use at elevated temperatures. In this study, hexagonal boron nitride nanosheets (hBNNSs) and titanium dioxide nanoparticles (TiO₂ NPs) were used to prepare water-based lubricants with glycerol and surfactant sodium dodecyl benzene sulfonate (SDBS) in water under ultrasonication. An Rtec ball-on-disk tribometer was used to investigate the tribological performance of the synthesised water-based lubricants containing different nano-hBN/TiO₂ concentrations, with dry and water conditions used as benchmarks. The results indicated that the water-based nanolubricant containing 0.5 wt% hBN and 0.5 wt% TiO₂ exhibited the best tribological performance at both ambient (25 °C) and elevated (500 °C) temperatures. This optimal concentration leads to a reduction in the coefficient of friction (COF) by 72.9% and 37.5%, wear of disk by 62.5% and 49%, and wear of ball by 74% and 69% at ambient and elevated temperatures, respectively, compared to that of distilled water. Lubrication mechanisms were attributed to the rolling, mending, tribofilm, solid layer formation, and synergistic effects of hBNNSs and TiO₂ NPs. Full article