Nanomaterials

26 pages, 5326 KB

Open AccessArticle

Species-Specific Stress Responses to Selenium Nanoparticles in Pseudomonas aeruginosa and Proteus mirabilis

by Kidon Sung, Miseon Park, Ohgew Kweon, Alena Savenka, Angel Paredes, Monica Sadaka, Saeed Khan, Seonggi Min and Steven Foley

Nanomaterials 2025, 15(18), 1404; https://doi.org/10.3390/nano15181404 (registering DOI) - 12 Sep 2025

Abstract

Urinary tract infections (UTIs) remain a major global health concern, with rising antimicrobial resistance prompting the search for alternative therapies. Selenium nanoparticles (Se NPs) are promising antimicrobial agents due to their unique physicochemical properties and ability to disrupt bacterial physiology. This study evaluated [...] Read more.

Urinary tract infections (UTIs) remain a major global health concern, with rising antimicrobial resistance prompting the search for alternative therapies. Selenium nanoparticles (Se NPs) are promising antimicrobial agents due to their unique physicochemical properties and ability to disrupt bacterial physiology. This study evaluated the antibacterial efficacy of Se NPs against four uropathogens and conducted comparative proteomic analyses to elucidate stress responses. Enumeration assays showed that Se NPs effectively inhibited bacterial growth, with Pseudomonas aeruginosa being the most susceptible and Proteus mirabilis the most resistant. Microscopy revealed Se NP-induced membrane rupture and cellular deformation across all species. Proteomic and bioinformatic analyses showed more pronounced protein regulation in P. mirabilis than in P. aeruginosa. Cluster of Orthologous Groups (COG) analysis revealed both shared and species-specific responses, while Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated activation of key stress pathways. Virulence-associated proteins were modulated in both species, with P. mirabilis uniquely upregulating stress survival and exotoxin-related proteins. Both regulated efflux pumps, suggesting active transport mitigates Se NP toxicity. P. aeruginosa showed mercury resistance, while P. mirabilis expressed tellurite resistance proteins. These findings highlight distinct yet overlapping strategies and support the potential of Se NPs in novel antimicrobial development. Full article

► Show Figures

Figure 1

23 pages, 2348 KB

Open AccessArticle

Comparative Carcinogenicity of Double-Walled Carbon Nanotubes of Different Lengths Administered by Intratracheal Installation into Rat Lungs

by Omnia Hosny Mohamed Ahmed, Dina Mourad Saleh, William T. Alexander, Hiroshi Takase, Yuhji Taquahashi, Motoki Hojo, Ai Maeno, Katsumi Fukamachi, Min Gi, Akihiko Hirose, Shuji Tsuruoka, Satoru Takahashi, Hiroyuki Tsuda and Aya Naiki-Ito

Nanomaterials 2025, 15(18), 1402; https://doi.org/10.3390/nano15181402 (registering DOI) - 11 Sep 2025

Abstract

We previously carried out an in vivo 2-year study to assess the potential toxicity/carcinogenicity of double-walled carbon nanotubes (DWCNTs) in a rat lung. We found that administration of DWCNTs by intratracheal–intrapulmonary spraying (TIPS) at a dose of 0.5 mg/rat induced the development of [...] Read more.

We previously carried out an in vivo 2-year study to assess the potential toxicity/carcinogenicity of double-walled carbon nanotubes (DWCNTs) in a rat lung. We found that administration of DWCNTs by intratracheal–intrapulmonary spraying (TIPS) at a dose of 0.5 mg/rat induced the development of lung tumors in 7 of 24 treated rats while 1 of 21 untreated rats and 1 of 25 vehicle treated rats developed lung tumors. In the current study, we administered DWCNTs of different lengths, 1.5 µm, 7 µm, and 15 µm, to rats by TIPS to investigate the possible effect of the length of this thin, flexible CNT on toxicity/carcinogenicity in rat lungs. Rats were administered DWCNTs with lengths of 1.5 µm (D1.5), 7 µm (D7), and 15 µm (D15) by TIPS once every other day over the course of two weeks for a total of eight administrations. The total dose administered was approximately 22 × 10¹² fibers per rat, corresponding to 0.0504 mg for D1.5, 0.232 mg for D7, and 0.504 mg for D15. Another group of rats was administered 0.5 mg MWCNT-7, a known carcinogen. Animals were killed at weeks 6 and 104 (4 and 102 weeks after the final TIPS administration). The mean survival time of the rats in the untreated, vehicle, D1.5, D7, and D15 groups was 99 to 104 weeks. One rat in the D1.5 group and one rat in the D15 group died before week 75. The remaining rats in the untreated, vehicle, D1.5, D7, and D15 groups were included in the final assessment of lung toxicity/carcinogenicity. In contrast, 11 rats in the MWCNT-7 group died before week 75 due to the development of malignant mesothelioma. Due to the much shorter survival time of the rats treated with MWCNT-7, accurate assessment of lung proliferative lesions in this group was not possible. At week 6, an increase in alveolar macrophages and granulation tissue foci in the alveoli was observed in all DWCNT administered groups. The alveolar epithelial cell PCNA index was also significantly increased in the D7 and D15 groups. Increases in alveolar macrophages, granulation tissue foci, and the alveolar epithelial cell PCNA index were observed in all DWCNT-treated groups at the final sacrifice. The incidences of lung tumors were 0/13, 0/12, 4/12, 3/8, and 2/10 in the untreated, vehicle, D1.5, D7, and D15 groups, respectively. In agreement with our previous study, the DWCNTs tested in the present study were carcinogenic in the rat lung. In addition, we present evidence that DWCNT fiber length may possibly have an effect on DWCNT-induced carcinogenicity in rat lungs. Full article

(This article belongs to the Special Issue Safety and Toxicity of Carbon Nanotubes, Nanoparticles and Other Nanomaterials: 2nd Edition)

► Show Figures

Graphical abstract

21 pages, 1153 KB

Open AccessArticle

Single- vs. Multi-Walled Carbon Nanotubes: Differential Cellular Stress and Lipid Metabolism Effects in Macrophage Models

by Sara Nahle, Hilary Cassidy, David Matallanas, Bertrand H. Rihn, Olivier Joubert and Luc Ferrari

Nanomaterials 2025, 15(18), 1401; https://doi.org/10.3390/nano15181401 - 11 Sep 2025

Abstract

This study examines the toxicological effects of carbon nanotubes (CNTs) of different diameters—single-walled CNTs (SWCNT, 2 nm) and multi-walled CNTs (MWCNT, 74 nm)—on two macrophage cell lines, rat alveolar NR8383 cells and human differentiated THP-1. Using standardized exposure conditions and employing an integrated [...] Read more.

This study examines the toxicological effects of carbon nanotubes (CNTs) of different diameters—single-walled CNTs (SWCNT, 2 nm) and multi-walled CNTs (MWCNT, 74 nm)—on two macrophage cell lines, rat alveolar NR8383 cells and human differentiated THP-1. Using standardized exposure conditions and employing an integrated omics approach (transcriptomic and proteomic analyses), both CNT types were found to induce cellular stress responses and inflammation, especially in NR8383 cells, with notable involvement of the Sirtuin signaling pathway. After 24 h, MWCNTs uniquely disrupted lipid metabolism in NR8383 cells, resulting in foam cell formation and syncytia. While SWCNTs were less disruptive to metabolic pathways, they significantly altered gene regulation, particularly RNA splicing mechanisms. The dispersion medium—fetal bovine serum (FBS) versus human surfactant—also modulated the observed toxicological responses, highlighting the critical role of the protein corona in influencing CNT-cell interactions. These findings demonstrate that CNT diameter significantly affects cytotoxicity and cellular response pathways in a cell-type-specific manner. Full article

(This article belongs to the Section Biology and Medicines)

16 pages, 2457 KB

Open AccessArticle

Humics-Functionalized Iron(III) Oxyhydroxides as Promising Nanoferrotherapeutics: Synthesis, Characterization, and Efficacy in Iron Delivery

by Anastasiya M. Zhirkova, Maria V. Zykova, Evgeny E. Buyko, Karina A. Ushakova, Vladimir V. Ivanov, Denis A. Pankratov, Elena V. Udut, Lyudmila A. Azarkina, Sergey R. Bashirov, Evgenii V. Plotnikov, Alexey N. Pestryakov, Mikhail V. Belousov and Irina V. Perminova

Nanomaterials 2025, 15(18), 1400; https://doi.org/10.3390/nano15181400 - 11 Sep 2025

Abstract

Iron deficiency anemia (IDA) remains a global health challenge. This study pioneers the use of humic substances (HS) as natural, biocompatible macroligands to develop safer and more effective nanoferrotherapeutics. We synthesized a series of nanoscale Fe(III) oxyhydroxide complexes stabilized by different HS, employing [...] Read more.

Iron deficiency anemia (IDA) remains a global health challenge. This study pioneers the use of humic substances (HS) as natural, biocompatible macroligands to develop safer and more effective nanoferrotherapeutics. We synthesized a series of nanoscale Fe(III) oxyhydroxide complexes stabilized by different HS, employing various solvents (ethanol, isopropanol, and acetone) and precipitation methods to isolate fractions with optimized properties. The nanocomposites were comprehensively characterized using inductively coupled plasma atomic emission spectrometry, total organic carbon analysis, X-ray diffraction, transmission electron microscopy, and Mössbauer spectroscopy. Cytotoxicity and iron bioavailability of all HS-Fe(III) formulations were assessed in Caco-2 intestinal epithelial cells. The type of HS and precipitation conditions significantly influenced the nanocomposites’ properties, yielding spherical nanoparticles (1–2 nm) of ferrihydrite or goethite. Physicochemical analysis confirmed that solvent-driven fractionation effectively tailored the nanocomposites’ size, crystallinity, and elemental composition. All HS-Fe(III) formulations demonstrated exceptional cytocompatibility, starkly contrasting the significant cytotoxicity of the reference drug Ferrum Lek^®. Several complexes, particularly CHSFe-Et67, surpassed Ferrum Lek^® in cellular iron uptake efficiency. We conclude that HS are a highly promising platform for developing effective and safe iron-delivery nanoferrotherapeutics, leveraging their natural polyfunctionality to enhance bioavailability and mitigate toxicity. Full article

► Show Figures

Figure 1

19 pages, 4479 KB

Open AccessArticle

Design of Electrostatic Nanocomplex of Semaglutide with Protamine and Zinc for Subcutaneous Prolonged Delivery

by In Gyu Yang, Jeong-Soo Kim and Myung Joo Kang

Nanomaterials 2025, 15(18), 1399; https://doi.org/10.3390/nano15181399 - 11 Sep 2025

Abstract

The aim of this study was to design a poorly water-soluble electrostatic nanocomplex of semaglutide (SMG) with protamine sulfate (PS) and zinc ions (Zn) for prolonged subcutaneous delivery. Complexation of SMG with the cationic peptide PS increased the lipophilicity (logP) proportionally from −4.7 [...] Read more.

The aim of this study was to design a poorly water-soluble electrostatic nanocomplex of semaglutide (SMG) with protamine sulfate (PS) and zinc ions (Zn) for prolonged subcutaneous delivery. Complexation of SMG with the cationic peptide PS increased the lipophilicity (logP) proportionally from −4.7 to 0.3, particularly in the presence of Zn. The optimized nanocomplex exhibited spherical morphology, an amorphous state, a particle size of 196.0 nm, and a zeta potential of −45.7 mV. In an in vitro dissolution test under sink conditions, native SMG showed rapid drug release with 98% dissolution within 24 h. In contrast, the nanocomplexes showed markedly delayed release, with a concentration-dependent relationship between PS/Zn contents and SMG release rate, exhibiting 19% drug release over 7 days in the optimized formula. These findings suggest that the proposed nanocomplex is a promising system for long-acting injectable delivery of SMG, potentially enhancing patient compliance in patients with obesity or type 2 diabetes. Full article

► Show Figures

Figure 1

16 pages, 5939 KB

Open AccessArticle

Mechanism of Tailoring Laser-Induced Periodic Surface Structures on 4H-SiC Crystal Using Ultrashort-Pulse Laser

by Erxi Wang, Chong Shan, Xiaohui Zhao, Huamin Kou, Qinghui Wu, Dapeng Jiang, Xing Peng, Penghao Xu, Zhan Sui and Yanqi Gao

Nanomaterials 2025, 15(18), 1398; https://doi.org/10.3390/nano15181398 - 11 Sep 2025

Abstract

In this study, we examine the characteristics of laser-induced periodic surface structures (LIPSSs) fabricated on N-doped 4H-SiC (N-SiC) and high-purity 4H-SiC (HP-SiC) crystals using femtosecond–picosecond lasers. The effects of various laser parameters on the orientation, size, and morphology of the LIPSS are systematically [...] Read more.

In this study, we examine the characteristics of laser-induced periodic surface structures (LIPSSs) fabricated on N-doped 4H-SiC (N-SiC) and high-purity 4H-SiC (HP-SiC) crystals using femtosecond–picosecond lasers. The effects of various laser parameters on the orientation, size, and morphology of the LIPSS are systematically investigated. The results reveal that, under identical laser irradiation conditions, the area of LIPSS on both N-SiC and HP-SiC increases linearly with the number of pulses, with N-SiC exhibiting a higher growth coefficient. Furthermore, analysis of differences in photothermal weak absorption and electric field modulation during the LIPSS fabrication process indicates that distinct SiC crystals yield varied LIPSS formation outcomes. This work not only elucidates the underlying physical mechanisms governing LIPSS formation on different silicon carbide crystal surfaces but also provides valuable guidance for precisely controlling the size and orientation of LIPSS regions on various 4H-SiC substrates. Full article

(This article belongs to the Section Nanophotonics Materials and Devices)

► Show Figures

Figure 1

14 pages, 3436 KB

Open AccessArticle

O₂-to-Ar Ratio-Controlled Growth of Ga₂O₃ Thin Films by Plasma-Enhanced Thermal Oxidation for Solar-Blind Photodetectors

by Rujun Jiang, Bohan Xiao, Yuna Lu, Zheng Liang and Qijin Cheng

Nanomaterials 2025, 15(18), 1397; https://doi.org/10.3390/nano15181397 - 11 Sep 2025

Abstract

Ga₂O₃ is an ultra-wide bandgap semiconductor material that has attracted significant attention for deep ultraviolet photodetector applications due to its excellent UV absorption capability and reliable stability. In this study, a novel plasma-enhanced thermal oxidation (PETO) method has been proposed [...] Read more.

Ga₂O₃ is an ultra-wide bandgap semiconductor material that has attracted significant attention for deep ultraviolet photodetector applications due to its excellent UV absorption capability and reliable stability. In this study, a novel plasma-enhanced thermal oxidation (PETO) method has been proposed to fabricate Ga₂O₃ thin films on the GaN/sapphire substrate in the gas mixture of Ar and O₂. By adjusting the O₂-to-Ar ratio (2:1, 4:1, and 8:1), the structural, morphological, and photoelectric properties of the synthesized Ga₂O₃ films are systematically studied as a function of the oxidizing atmosphere. It is demonstrated that, at an optimal O₂-to-Ar ratio of 4:1, the synthesized Ga₂O₃ thin film has the largest grain size of 31.4 nm, the fastest growth rate of 427.5 nm/h, as well as the lowest oxygen vacancy concentration of 16.61%. Furthermore, the nucleation and growth of Ga₂O₃ thin films on the GaN/sapphire substrate by PETO is proposed. Finally, at the optimized O₂-to-Ar ratio of 4:1, the metal–semiconductor–metal-structured Ga₂O₃-based photodetector achieves a specific detectivity of

2.74 \times 10^{13}

Jones and a solar-blind/visible rejection ratio as high as 116 under a 10 V bias. This work provides a promising approach for the cost-effective fabrication of Ga₂O₃ thin films for UV photodetector applications. Full article

(This article belongs to the Special Issue State-of-the-Art Nanostructured Photodetectors)

► Show Figures

Figure 1

13 pages, 4343 KB

Open AccessArticle

Impact of Four-Phonon Scattering on Thermal Transport and Thermoelectric Performance of Penta-XP₂ (X = Pd, Pt) Monolayers

by Yangshun Lan, Yueyu Zhang, Honggang Zhang, Ping Wang, Ning Wang, Yangjun Yan, Xiaoting Zha, Changchun Ding, Yuzhi Li, Chuanfu Li, Yunjun Gu and Qifeng Chen

Nanomaterials 2025, 15(18), 1396; https://doi.org/10.3390/nano15181396 - 11 Sep 2025

Abstract

Accurately understanding and modulating thermal and thermoelectric transport in penta-XP₂ (X = Pd, Pt) monolayers is crucial for their applications in nanoelectronics and energy conversion. We systematically investigate the thermal conductivity and thermoelectric properties of penta-XP₂ monolayers through first-principles calculations, incorporating [...] Read more.

Accurately understanding and modulating thermal and thermoelectric transport in penta-XP₂ (X = Pd, Pt) monolayers is crucial for their applications in nanoelectronics and energy conversion. We systematically investigate the thermal conductivity and thermoelectric properties of penta-XP₂ monolayers through first-principles calculations, incorporating four-phonon (4ph) scattering and electron–phonon interaction (EPI) effects. The 4ph scattering, particularly Umklapp and redistribution processes, markedly suppresses lattice thermal conductivity by generating substantial thermal resistance and disrupting phonon population distributions. At 300 K, the lattice thermal conductivity is reduced to 0.87 W/mK (80% reduction) for penta-PdP₂ and 1.64 W/mK (79% reduction) for penta-PtP₂ compared to three-phonon-only scattering. Combining this with EPI-optimized electronic transport yields enhanced thermoelectric figures of merit (ZT), increasing from 0.21 to 0.86 for penta-PdP₂ and from 0.11 to 0.34 for penta-PtP₂, alongside a broadened optimal carrier concentration range. These findings highlight momentum-conserving 4ph scattering as a key mechanism for phonon transport modulation and thermoelectric efficiency improvement in penta-XP₂ materials, providing theoretical guidance for designing high-performance nanoscale thermal management and energy conversion devices. Full article

(This article belongs to the Special Issue Structural Modeling and Theoretical Study of Low-Dimensional Materials)

► Show Figures

Figure 1

29 pages, 4897 KB

Open AccessReview

Review of Current Achievements in Dendrimers and Nanomaterials for Potential Detection and Remediation of Chemical, Biological, Radiological and Nuclear Contamination—Integration with Artificial Intelligence and Remote Sensing Technologies

by Agnieszka Gonciarz, Robert Pich, Krzysztof A. Bogdanowicz, Witalis Pellowski, Jacek Miedziak, Sebastian Lalik, Marcin Szczepaniak, Monika Marzec and Agnieszka Iwan

Nanomaterials 2025, 15(18), 1395; https://doi.org/10.3390/nano15181395 - 10 Sep 2025

Abstract

Current scientific and technological developments indicate that the need for dendrimers and nanomaterials should be taken into account in aspects such as the detection and remediation of chemical, biological, radiological and nuclear (CBRN) contamination. To evaluate the benefits of dendrimers in CBRN contamination, [...] Read more.

Current scientific and technological developments indicate that the need for dendrimers and nanomaterials should be taken into account in aspects such as the detection and remediation of chemical, biological, radiological and nuclear (CBRN) contamination. To evaluate the benefits of dendrimers in CBRN contamination, different characterization methods, toxicological evaluation, and recyclability must be used. The aim of this article is to systematize knowledge about selected nanomaterials and dendrimers as well as chemical, biological, radiological and nuclear (CBRN) hazards in accordance with the principles of green chemistry, engineering, technology and environmental safety. So far, many review articles on dendrimers and nanomaterials have focused on biomedical applications or environmental remediation. In this article, we discuss this topic in more detail, especially in relation to the integration of dendrimers with artificial intelligence and remote sensing technologies. We highlight interdisciplinary synergies—artificial intelligence for smarter design and remote sensing for deployment—that could bridge the gap between nanoscale innovation and real CBRN countermeasures. Full article

(This article belongs to the Special Issue Advanced Nanomaterials for Bioimaging: 2nd Edition)

► Show Figures

Graphical abstract

15 pages, 2415 KB

Open AccessArticle

Pd/SiC-Catalyzed Visible-Light-Driven N-Methylation of Nitroaranes Using Formaldehyde

by Dongfang Hou, Ruifeng Guo, Xianshu Dong, Yuping Fan, Jingru Wang and Xili Tong

Nanomaterials 2025, 15(18), 1394; https://doi.org/10.3390/nano15181394 - 10 Sep 2025

Abstract

Pd nanoparticles (Pd/SiC) with a main exposed plane of Pd (111) were prepared by liquid phase reduction. The use of formaldehyde as a methylation reagent for the photocatalytic methylation of aromatic nitro compounds to N,N-methylaniline resulted in one-pot methylations of aromatic nitro compounds [...] Read more.

Pd nanoparticles (Pd/SiC) with a main exposed plane of Pd (111) were prepared by liquid phase reduction. The use of formaldehyde as a methylation reagent for the photocatalytic methylation of aromatic nitro compounds to N,N-methylaniline resulted in one-pot methylations of aromatic nitro compounds with high photocatalytic activity and selectivity under mild reaction conditions. The high catalytic activity of Pd/SiC in N-methylation reactions arises from the Mott–Schottky contact between Pd and SiC, which promotes the transfer of photogenerated electrons to Pd. The high selectivity is ascribed to the ability of Pd nanoparticles to catalyze the hydrogenation of nitro groups to amino groups, which subsequently undergo direct methylation with formaldehyde, bypassing the intermediate formylation step. Full article

► Show Figures

Figure 1

13 pages, 3419 KB

Open AccessArticle

Semiconducting Tungsten Trioxide Thin Films for High-Performance SERS Biosensors

by Hao Liu, Liping Chen, Bicheng Li, Haizeng Song, Chee Leong Tan, Yi Shi and Shancheng Yan

Nanomaterials 2025, 15(18), 1393; https://doi.org/10.3390/nano15181393 - 10 Sep 2025

Abstract

Surface-enhanced Raman Scattering (SERS) enables ultrasensitive detection but is often hindered by biocompatibility and sustainability concerns due to its reliance on noble metal substrates. To overcome these limitations, we develop a semiconductor-based SERS platform utilizing ultrathin tungsten trioxide (WO₃) nanofilms synthesized [...] Read more.

Surface-enhanced Raman Scattering (SERS) enables ultrasensitive detection but is often hindered by biocompatibility and sustainability concerns due to its reliance on noble metal substrates. To overcome these limitations, we develop a semiconductor-based SERS platform utilizing ultrathin tungsten trioxide (WO₃) nanofilms synthesized via a facile annealing process on fluorine-doped tin oxide (FTO). This system achieves an impressive Raman enhancement factor of 1.36 × 10⁶, enabling ultrasensitive detection of rhodamine 6G (R6G) and methylene blue (MB) at ultralow concentrations, surpassing conventional metal-based SERS platforms. It is further suggested that this is a substrate that can be easily coupled to other metals. An application for the detection of adenine molecules is realized through layered WO₃-Au NPs composites, where embedded gold nanoparticles act as plasma “hot spots” to amplify the sensitivity. Density functional theory (DFT) calculations and band structure analysis confirm that synergistic interface charge transfer and naturally formed oxygen vacancies enhance performance. By combining semiconductor compatibility with other metal amplification, this WO₃-based SERS platform offers a sustainable and high-performance alternative to conventional substrates, paving the way for environmentally friendly and scalable Raman sensing technologies. Full article

(This article belongs to the Section Nanoelectronics, Nanosensors and Devices)

► Show Figures

Figure 1

24 pages, 5466 KB

Open AccessArticle

From Spirulina platensis to Nanomaterials: A Comparative Study of AgNPs Obtained from Two Extracts

by Alexandra Ivanova, Mina Todorova, Dimitar Petrov, Zhana Petkova, Olga Teneva, Ginka Antova, Maria Angelova-Romova, Velichka Yanakieva, Slava Tsoneva, Vera Gledacheva, Krastena Nikolova, Daniela Karashanova and Stoyanka Nikolova

Nanomaterials 2025, 15(18), 1392; https://doi.org/10.3390/nano15181392 - 10 Sep 2025

Abstract

This study presents the synthesis and characterization of silver nanoparticles (AgNPs) using two Spirulina platensis extracts: one of them cultivated in a bioreactor in Bulgaria (near Varvara village), and the other one from the local market in Bulgaria (Dragon Superfoods). To assess their [...] Read more.

This study presents the synthesis and characterization of silver nanoparticles (AgNPs) using two Spirulina platensis extracts: one of them cultivated in a bioreactor in Bulgaria (near Varvara village), and the other one from the local market in Bulgaria (Dragon Superfoods). To assess their properties and stability, ATR-FTIR, TEM (Transmission Electron Microscopy) images, and zeta potential were used. Chemical content of the extracts and AgNPs obtained were assessed, as well as their antimicrobial and anti-inflammatory activities. We found that the extracts’ origin significantly influenced nanoparticle morphology, surface charge, and bioactivity. AgNPs were spherical and different in size from Bioreactor 4–8 nm, while Dragon obtained larger particles, about 20 nm. We found that synthesis altered the chemical content of the extracts, particularly in lipid, protein, and tocopherol content, suggesting active involvement of Spirulina-derived biomolecules in nanoparticle formation. Antimicrobial assays showed slightly higher activity for Dragon AgNPs against P. aeruginosa (21 mm) and S. enteritidis (23 mm), with similar effects against L. monocytogenes and S. aureus. At 2.5 mg/mL, both samples protected human albumin from thermal denaturation more effectively (23.36% and 20.07%) than prednisolone (16.99%). Based on the obtained results, AgNPs from Spirulina platensis can be attributed as multifunctional agents with anti-inflammatory and antimicrobial activity. Full article

(This article belongs to the Special Issue Synthesis of Functional Nanoparticles for Biomedical Applications)

► Show Figures

Figure 1

29 pages, 7118 KB

Open AccessArticle

Chemical Mechanical Polishing of Zerodur^® Using Silica and Ceria Nanoparticles: Toward Ultra-Smooth Optical Surfaces

by Houda Bellahsene, Saad Sene, Gautier Félix, Nicolas Fabregue, Michel Marcos, Arnaud Uhart, Jean-Charles Dupin, Erwan Oliviero, Joulia Larionova, Marc Ferrari and Yannick Guari

Nanomaterials 2025, 15(18), 1391; https://doi.org/10.3390/nano15181391 - 10 Sep 2025

Abstract

This study investigates hyperpolishing of Zerodur^® substrates via chemical-mechanical polishing (CMP) using silica (SiO₂) and ceria (CeO₂) nanoparticles as controlled nano-abrasives. A pre-polishing stress-mirror stage was combined with systematic use of nanoparticles of variable size to evaluate surface-state [...] Read more.

This study investigates hyperpolishing of Zerodur^® substrates via chemical-mechanical polishing (CMP) using silica (SiO₂) and ceria (CeO₂) nanoparticles as controlled nano-abrasives. A pre-polishing stress-mirror stage was combined with systematic use of nanoparticles of variable size to evaluate surface-state evolution via optical rugosimeter, HRSEM, cross-sectional HRTEM, and XPS. A set of hexagonal mirrors with a circumscribed diameter of 30 mm was polished for one hour with each nanoparticle type. All tested slurries significantly improved surface quality, with both the smallest (37 nm) and largest (209 nm) SiO₂ particles achieving similar final roughness, though larger particles showed a slight performance advantage that could be offset by longer polishing with smaller particles. CeO₂ nanoparticles (30 nm) produced even better process efficiency and surface finishes than 37 nm SiO₂, demonstrating higher chemical-mechanical polishing efficiency with CeO₂. Sequential polishing strategies, first with 209 nm SiO₂, then with 37 nm SiO₂ and 30 nm CeO₂, also enhanced surface quality, confirming trends from single-particle trials. One of the most effective protocols was adapted and scaled up to 135 mm Zerodur^® mirrors with spherical and plano geometries, representative of precision optical components. The strategic approach adopted to achieve a high-quality surface finish in a reduced processing time relies on the sequential use of nanoparticles acting as complementary nano-abrasives. Indeed, applying two hours of polishing with 209 nm SiO₂ followed by two hours with 37 nm SiO₂ yielded exceptional results, with area roughness (Sa) values of 1 Å for spherical and 0.9 Å for plano surfaces. These results demonstrate the capability of nanoparticle-assisted CMP to produce sub-nanometric surface finishes and offer a robust, scalable approach for high-end optical manufacturing. Full article

► Show Figures

Graphical abstract

16 pages, 1624 KB

Open AccessArticle

Oxidation of Supported Nickel Nanoparticles: Effects of Lattice Strain and Vibrational Excitations of Active Sites

by Sergey Yu. Sarvadii, Andrey K. Gatin, Nadezhda V. Dokhlikova, Sergey A. Ozerin, Vasiliy A. Kharitonov, Dinara Tastaibek, Vladislav G. Slutskii and Maxim V. Grishin

Nanomaterials 2025, 15(18), 1390; https://doi.org/10.3390/nano15181390 - 10 Sep 2025

Abstract

This work investigated the oxidation in an atmosphere of N₂O of different surface areas of single nickel nanoparticles deposited on highly oriented pyrolytic graphite (HOPG). Using scanning tunneling microscopy and spectroscopy, it was shown that oxide formation begins at the top [...] Read more.

This work investigated the oxidation in an atmosphere of N₂O of different surface areas of single nickel nanoparticles deposited on highly oriented pyrolytic graphite (HOPG). Using scanning tunneling microscopy and spectroscopy, it was shown that oxide formation begins at the top of the nanoparticle, while the periphery is resistant to oxidation. The active site of oxygen incorporation is a vibrationally excited group of nickel atoms, and the gap between them is the place where an oxygen adatom penetrates. The characteristic time of vibrational relaxation of the active site is 10⁻⁹–10⁻⁷ s. The reason for the oxidation resistance is the deformation of the nanoparticle atomic lattice near the Ni-HOPG interface. A relative compression of the nanoparticle atomic lattice ξ = 0.4–0.8% was shown to be enough for such an effect to manifest. Such compression increases the activation energy for oxygen incorporation by 6–12 kJ/mol, resulting in inhibition of oxide growth at the periphery of the nanoparticle. In fact, in this work, oxygen adatoms served as probes, and their incorporation between nickel atoms allowed the measurement of the nanoparticle’s lattice parameters at different distances from the Ni–HOPG interface. The developed theoretical framework not only accounts for the observed oxidation behavior but also offers a potential pathway to estimate charge transfer and local work functions for deposited nickel catalysts. Full article

(This article belongs to the Special Issue Recent Advances in Surface and Interface Nanosystems)

► Show Figures

Figure 1

1 pages, 133 KB

Open AccessCorrection

Correction: Zhou et al. Flexible and Effective Preparation of Magnetic Nanoclusters via One-Step Flow Synthesis. Nanomaterials 2022, 12, 350

by Lin Zhou, Lu Ye and Yangcheng Lu

Nanomaterials 2025, 15(18), 1389; https://doi.org/10.3390/nano15181389 - 10 Sep 2025

Abstract

Following publication, concerns were raised regarding the relevance of a few references in this publication [...] Full article

56 pages, 17494 KB

Open AccessReview

Sustainable Materials for Energy

by Filippo Agresti, Giuliano Angella, Humaira Arshad, Simona Barison, Davide Barreca, Paola Bassani, Simone Battiston, Carlo Alberto Biffi, Maria Teresa Buscaglia, Giovanna Canu, Francesca Cirisano, Silvia Maria Deambrosis, Angelica Fasan, Stefano Fasolin, Monica Favaro, Michele Ferrari, Stefania Fiameni, Jacopo Fiocchi, Marco Fortunato, Donatella Giuranno, Parnian Govahi, Jacopo Isopi, Francesco Montagner, Cecilia Mortalò, Enrico Miorin, Rada Novakovic, Luca Pezzato, Daniela Treska, Ausonio Tuissi, Barbara Vercelli, Francesca Villa, Francesca Visentin, Valentina Zin and Maria Losurdo Show full author list Hide full author list

Nanomaterials 2025, 15(18), 1388; https://doi.org/10.3390/nano15181388 - 10 Sep 2025

Abstract

The sustainable production of energy without environmental footprints is a challenge of paramount importance to satisfy the ever-increasing global demand and to promote economic and social growth through a greener perspective. Such awareness has significantly stimulated worldwide efforts aimed at exploring various energy [...] Read more.

The sustainable production of energy without environmental footprints is a challenge of paramount importance to satisfy the ever-increasing global demand and to promote economic and social growth through a greener perspective. Such awareness has significantly stimulated worldwide efforts aimed at exploring various energy paths and sources, in compliance with the ever more stringent environmental regulations. Research advancements in these fields are directly dependent on the design, fabrication, and implementation of tailored multi-materials for efficient energy production and harvesting and storage devices. Herein, we aim at providing a survey on the ongoing research activities related to various aspects of functional materials for energy production, conversion, and storage. In particular, we present the opportunities and the main open challenges related to multifunctional materials spanning from carbon-based nanostructures for chemical energy conversion, ferroelectric ceramics for energy harvesting, and phase change materials for thermal energy storage to metallic materials for hydrogen technologies, heat exchangers for wind energy, and amphiphobic coatings for the protection of solar panels. The relevance of designing tailored materials for power generation is also presented. Finally, the importance of applying life cycle assessment to materials is emphasized through the case study of AlTiN thin films. Full article

► Show Figures

Graphical abstract

3 pages, 185 KB

Open AccessCorrection

Correction: Motamedi et al. Enhancement of Thermostability of Aspergillus flavus Urate Oxidase by Immobilization on the Ni-Based Magnetic Metal–Organic Framework. Nanomaterials 2021, 11, 1759

by Neda Motamedi, Mahmood Barani, Azadeh Lohrasbi-Nejad, Mojtaba Mortazavi, Ali Riahi-Medvar, Rajender S. Varma and Masoud Torkzadeh-Mahani

Nanomaterials 2025, 15(18), 1387; https://doi.org/10.3390/nano15181387 - 10 Sep 2025

Abstract

There was an update made to the original publication [...] Full article

(This article belongs to the Special Issue Synthesis, Development and Characterization of Magnetic Nanomaterials)

10 pages, 2582 KB

Open AccessArticle

High-Field Nonlinear Terahertz Conductivities of Iron Ultrathin Films

by Lewen Zhu, Zhiqiang Lan, Yingyu Guo, Danni Li, Lin Xi, Huiping Zhang and Zuanming Jin

Nanomaterials 2025, 15(18), 1386; https://doi.org/10.3390/nano15181386 - 9 Sep 2025

Abstract

The electronic transport behavior in ferromagnetic thin films critically dictates the functionality and efficiency of devices in spintronics and modern materials science. This work characterizes terahertz (THz) responses and nonlinear conductivities of Fe ultrathin films under high-field THz excitation. We demonstrated that different [...] Read more.

The electronic transport behavior in ferromagnetic thin films critically dictates the functionality and efficiency of devices in spintronics and modern materials science. This work characterizes terahertz (THz) responses and nonlinear conductivities of Fe ultrathin films under high-field THz excitation. We demonstrated that different nonlinearities are present for two different thickness samples. For a 2 nm thick Fe film, as the peak THz electric field was increased to 369 kV/cm, the THz transmittance of Fe films generally decreased. However, for the 4 nm thick Fe film, the THz transmittance is almost field strength independent. This result is correlated with the conductivity variations induced by carrier transport processes. The real part of the complex conductivity for the 2 nm thick film increased significantly with the THz electric field, while the 4 nm thick film showed negligible dependence. In addition, we extracted the frequency-domain complex conductivity of the Fe thin films and used the Drude or Drude–Smith model to explain the distinct behaviors between the two thickness samples under intense THz fields, mainly associated with the surface morphology. This work aims to elucidate the transport properties of Fe films in the THz frequency range. Our findings lay a crucial foundation for the design and development of future high-performance THz spintronic functional devices. Full article

(This article belongs to the Special Issue Nanomaterials and Nanostructures for Spintronic Terahertz Devices)

► Show Figures

Graphical abstract

11 pages, 2022 KB

Open AccessArticle

Thickness Influences on Structural and Optical Properties of Thermally Annealed (GaIn)₂O₃ Films

by Shiyang Zhang, Fabi Zhang, Tangyou Sun, Zanhui Chen, Xingpeng Liu, Haiou Li, Shifeng Xie, Wanli Yang and Yue Li

Nanomaterials 2025, 15(18), 1385; https://doi.org/10.3390/nano15181385 - 9 Sep 2025

Abstract

This work explores the relationship between the thickness and the structural, morphological, and optical features of thermally annealed (GaIn)₂O₃ thin films grown by pulsed laser deposition at room temperature. The thickness of the (GaIn)₂O₃ films varied from [...] Read more.

This work explores the relationship between the thickness and the structural, morphological, and optical features of thermally annealed (GaIn)₂O₃ thin films grown by pulsed laser deposition at room temperature. The thickness of the (GaIn)₂O₃ films varied from 20 to 391 nm with an increase in deposition time. The film with a thickness of about 105 nm showed largest grain size as well as the strongest XRD peak intensity, as measured by atomic force microscopy and X-ray diffraction. The studies on the optical properties show that the bandgap value decreased from 5.14 to 4.55 eV with the change in the film thickness from 20 to 391 nm. The film thickness had a significant impact on the structure, morphology, and optical properties of (GaIn)₂O₃, and the PLD growth mode notably influenced the film quality. The results suggest that optimizing the film thickness is essential for improving the film quality and achieving the target bandgap. Full article

► Show Figures

Figure 1

16 pages, 1541 KB

Open AccessArticle

Carbyne-Enriched Carbon Coatings on Silicon Chips as Biosensing Surfaces with Stable-over-Time Biomolecule Binding Capacity

by Dimitra Tsounidi, Panagiota Petrou, Mariya Aleksandrova, Tsvetozar Tsanev, Angeliki Tserepi, Evangelos Gogolides, Andrzej Bernasik, Kamil Awsiuk, Natalia Janiszewska, Andrzej Budkowski and Ioannis Raptis

Nanomaterials 2025, 15(18), 1384; https://doi.org/10.3390/nano15181384 - 9 Sep 2025

Abstract

Carbyne-containing materials offer significant potential for biosensor applications due to their unique chemical and mechanical properties. In this study, carbyne-enriched carbon coatings deposited on SiO₂/Si chips using ion-assisted pulse-plasma deposition were evaluated for the first time as substrates for optical biosensing. [...] Read more.

Carbyne-containing materials offer significant potential for biosensor applications due to their unique chemical and mechanical properties. In this study, carbyne-enriched carbon coatings deposited on SiO₂/Si chips using ion-assisted pulse-plasma deposition were evaluated for the first time as substrates for optical biosensing. At first, the carbyne-enriched coatings were characterized by X-ray photoelectron spectroscopy, Raman spectroscopy, Atomic Force Microscopy, and the sessile drop method to assess their composition, structure, and wettability. After that, chips with carbyne-enriched coatings were modified with biomolecules through physical absorption or covalent bonding, and the respective biomolecular interactions were monitored in real-time by White Light Reflectance Spectroscopy (WLRS). In both cases, SiO₂/Si chips modified with an aminosilane were used as reference substrates. Physical adsorption was tested through immobilization of an antibody against C-reactive protein (CRP) to enable its immunochemical detection, whereas covalent bonding was tested through coupling of biotin and monitoring its reaction with streptavidin. It was found that the carbyne-enriched carbon-coated chips retained both their antibody adsorption capability and their covalent bonding ability for over 18 months, while the modified with aminosilane SiO₂/Si chips lost 90% of their antibody adsorption capacity and covalent bonding ability after two months of storage. These findings highlight the strong potential of carbyne-enriched carbon-coated chips as robust biosensing substrates, with applications extending beyond WLRS. Full article

► Show Figures

Graphical abstract

11 pages, 3833 KB

Open AccessArticle

Preparation of Ag-Decorated TiO₂ Composite Materials and Study on Photocatalytic Performance

by Hongfei Dou, Jie Wang, Yan Zhao, Junjie Liu and Yannan Li

Nanomaterials 2025, 15(18), 1383; https://doi.org/10.3390/nano15181383 - 9 Sep 2025

Abstract

Aiming at the insufficient broad-spectrum absorption and high carrier complexation rate in the photocatalytic antimicrobial application of TiO₂, Ag/TiO₂ composite materials were prepared by co-precipitation method in this study. The material characterization showed that Ag was uniformly dispersed on the [...] Read more.

Aiming at the insufficient broad-spectrum absorption and high carrier complexation rate in the photocatalytic antimicrobial application of TiO₂, Ag/TiO₂ composite materials were prepared by co-precipitation method in this study. The material characterization showed that Ag was uniformly dispersed on the TiO₂ surface in the form of nanoparticles, and the specific surface area of Ag/TiO₂ composite materials was enhanced by 59.6% compared with that of pure TiO₂, and the mesoporous structure was significantly optimized. Visible photocatalytic tests showed that the degradation rate of Ag/TiO₂ composite materials for Rh B and M O was more than two times higher than that of pure TiO₂. Under dark conditions, the material showed a minimum inhibitory concentration (MIC) of 62.5 μg/mL against Escherichia coli and Staphylococcus aureus, with an antimicrobial rate of 99.8% for 8 h, confirming its non-light-dependent antimicrobial activity. Mechanistic studies revealed that photogenerated electrons were efficiently captured by Ag nanoparticles, which inhibited e-h⁺ complexation; meanwhile, the photothermal effect (ΔT > 15 °C) promoted the sustained release of Ag⁺, which realized the triple synergistic antimicrobial activity by disrupting the bacterial membrane and interfering with metabolism. This study provides a new strategy for the development of efficient solar-powered water treatment materials. Full article

(This article belongs to the Special Issue Green Nanoparticles and Nanocomposites for Water Remediation: Synthesis and Current Applications)

► Show Figures

Graphical abstract

Journal Menu

Journal Browser

Nanomaterials, Volume 15, Issue 18 (September-2 2025) – 21 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI