Micro & Nano Letters最新文献

{"title":"Photodegradation of Tropaeolin O in the Presence of Ag-Doped ZnO Nanoparticles","authors":"S. Bailón-Ruiz, Y. Cedeño-Mattei, K. Torres-Torres, L. Alamo-Nole","doi":"10.3390/micro3030045","DOIUrl":"https://doi.org/10.3390/micro3030045","url":null,"abstract":"Azo dyes such as Tropaeolin O have diverse applications in the textile, food, and biomedical industries. However, their recalcitrant properties make them toxic substances in surface waters. Nanocatalysts are photoactive nanoparticles that generate reactive oxygen species to destroy organic compounds. Moreover, the presence of dopant agents in the nanoparticles’ crystalline structure efficiently enhances photocatalytic activity. Ag-doped ZnO nanoparticles were prepared in ethylene glycol at 197 °C and characterized by UV-Vis absorption, photoluminescence, high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDX), and electron diffraction (ED). The particles were mainly spherical with a size of ~10 nm, a hexagonal structure, and an elemental composition of 56.2% Zn, 37.8% O, and 5.9% Ag. The particles evidenced a broad absorption peak in the UV region and two emission peaks. Absorption analysis indicates that 92% and 58% of Tropaeolin O were degraded using 100 and 50 ppm of Ag-doped ZnO nanoparticles, respectively, during the first 550 min. Ion chromatograms selected using quadrupole time-of-flight liquid chromatography-mass spectrometry (QTOF-LC-MS) indicate a complete Tropaeolin O degradation (295.04 m/z) during the first 330 min. Initially, the nanocatalyst attacks the electron-rich groups (-OH and -NH), generating the 277.03 m/z [M-OH]+ and 174.02 m/z (molecule rupture on the azo group). In addition, small oxidized fragments 167.03 m/z and 114.03 m/z confirm the nanoparticles’ photocatalytic capacity, and oxidized chains indicate the tropaeolin’s opening rings (including phtalic acids) and mineralization.","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"12 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82200413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extraction and Modification of Cellulose Microfibers Derived from Biomass of the Amazon Ochroma pyramidale Fruit","authors":"A. Rocha, B. D. A. Feitosa, A. S. Carolino, Ronald Zico de Aguiar Nunes, Célio Matias Airone Macalia, Kalil Araújo da Silva, Cleverton Oliveira Dias, S. M. de Souza, P. Campelo, J. Bezerra, E. Sanches","doi":"10.3390/micro3030046","DOIUrl":"https://doi.org/10.3390/micro3030046","url":null,"abstract":"Microfibers are important to several areas of human lifestyle, and the knowledge about their physicochemical characteristics allows for proposing new technological applications. The in natura microfiber of Ochroma pyramidale fruit (IN sample) and its extracted pulp (PU sample) were evaluated by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetry and Differential Scanning Calorimetry (TG/dTG and DSC). Microfibers were composed mainly of (68 ± 1)% holocellulose, (35.8 ± 0.1)% cellulose, (32 ± 3)% lignin and (3.7 ± 0.3)% extractives. The XRD pattern of the PU sample revealed that the mercerization process resulted in the change of the cellulose crystal structure from Iα type (triclinic) to type II (monoclinic). The SEM technique showed that the IN sample presented regular cylindrical/hollow-shaped wire-like microfibers with diameters ranging from 5 µm to 25 µm. However, the mercerization process changed their natural morphology. A significant change in the FTIR spectra after the removal of hemicellulose and lignin components was observed: weak bands at 1739 cm−1 (C=O stretching of lignin and hemicellulose fractions), 1463 cm−1 (CH3 of lignin) and 1246 cm−1 (C-O of lignin) were still observed in the PU sample, indicating that the lignin was not completely removed due to the natural difficulty of isolating pure cellulose. The TG/dTG and DSC evaluation revealed a temperature increase of the second thermal event (starting at 235 °C) in the PU sample, which was assigned to the cellulose and residual hemicellulose degradation. Then, this work aimed to disseminate and characterize a microfiber with unusual characteristics still little explored by the scientific community, as well as its cellulosic pulp, providing information that may be useful in its application in different industries, enabling the positive development of new biocompatible, renewable and sustainable materials.","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"66 1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79283612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A chitosan-based hydrogel containing zinc oxide nanoparticles as a carrier for improving antibacterial activity and controlling the release of antibiotics","authors":"Ali Rastegari,&nbsp;Fatemeh Hasanshakir,&nbsp;Zohreh Mohammadi,&nbsp;Fatemeh Saadatpor,&nbsp;Homa Faghihi,&nbsp;Fatemeh Moraffah","doi":"10.1049/mna2.12172","DOIUrl":"https://doi.org/10.1049/mna2.12172","url":null,"abstract":"<p>Microbial infections are considered one of the most important concerns of the world community. Developing drug delivery systems based on formulation of nanoparticles (NPs) with antimicrobial agents has shown beneficial effectiveness against microbial infections and related antimicrobial resistance. In this study, the authors prepared and characterized a chitosan-based hydrogel loaded with zinc oxide NPs for controlling the release of vancomycin and also improving its antibacterial effect. Characterization studies demonstrated that the developed biopolymeric hydrogel was able to sustain and control the release of vancomycin in response to acidic media for 96 h. Furthermore, antimicrobial studies showed significant and efficient antibacterial activity of prepared hydrogel against <i>Staphylococcus aureus</i> and <i>Pseudomonas aeruginosa</i>. Based on the obtained results, it can be concluded that the prepared chitosan hydrogel (CH) containing zinc oixde (ZnO) NPs has a desirable activity for controlling the release of vancomycin and improving its antibacterial properties.</p>","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"18 7","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/mna2.12172","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50120243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation of the Dynamics of Supersonic N-Crowdions in fcc Lead and Nickel","authors":"A. Bayazitov, A. Semenov, S. V. Dmitriev","doi":"10.3390/micro3030044","DOIUrl":"https://doi.org/10.3390/micro3030044","url":null,"abstract":"In the case where an interstitial atom is located in a close-packed atomic row of the crystal lattice, it is called a crowdion. Crowdions play an important role in the processes of mass and energy transfer resulting from irradiation, severe plastic deformation, ion implantation, plasma and laser processing, etc. In this work, supersonic N-crowdions (N=1, 2) in fcc lattices of lead and nickel are studied by the method of molecular dynamics. Modeling shows that the propagation distance of a supersonic 2-crowdion in lead at a high initial velocity is less than that of a supersonic 1-crowdion. In other fcc metals studied, including nickel, supersonic 2-crowdions have a longer propagation distance than 1-crowdions. The relatively short propagation distance of supersonic 2-crowdions in lead is due to their instability and rapid transformation into supersonic 1-crowdions. This feature of the dynamics of supersonic N-crowdions in lead explains its high radiation-shielding properties.","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"8 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74305274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation of chitosan-embedded recombinant human epidermal growth factor nanoparticles as accelerating compounds for skin remodelling in chronic lesions","authors":"Saadeh Hashemi,&nbsp;Elnaz Mihandoost,&nbsp;Sepideh Khaleghi","doi":"10.1049/mna2.12171","DOIUrl":"https://doi.org/10.1049/mna2.12171","url":null,"abstract":"<p>The chronic lesion has become a major biological difficulty. Using nanoparticles as drug delivery systems is remarkable nowadays. The unique properties of chitosan in combination with epidermal growth factor (EGF) can accelerate the wound-healing process.</p><p>In this study, Chitosan-EGF (CS-EGF) nanoparticles were manipulated and characterized by Transmission Electron Microscopy (TEM) microscopy, dynamic light scattering (DLS) method, and Fourier Transform Infrared Spectroscopy (FTIR) radiation. The antibacterial effect was estimated by minimum inhibitory concentration (MIC)/minimum bactericidal concentration (MBC) methods and the proliferation assay was measured on the HFF-1 (human fibroblast cell line). Then, migration assay was accomplished and the gene expression analysis for transforming growth factor-beta (TGF-β), vascular endothelial growth factor (VEGF), and platelets-derived growth factor (PDGF) was manipulated by the real-time-PCR method. The obtained results were considered statistically significant with <i>P</i> &lt; 0.05.</p><p>Obtained results illustrated no toxic effect on the HFF-1 cell line treated with CS-EGF. In cellular proliferation and migration assays, CS-EGF nanoparticles demonstrated 2-folds higher than the control. In the duration of 72 h of the experiment, and concentration of 10 µM, 90 ±10% of cells were migrated and the whole scratch was covered by fibroblasts. The real-time-PCR analysis also showed 7.5, 4.5-, and 7-fold upregulation of all TGF-β, VEGF, and PDGF genes in comparison with the control group.</p><p>This study confirmed that using chitosan nanoparticles as a carrier for EGF can accelerate cellular remodelling and annihilate bacterial infection in the process of treatment. As CS-EGF nanoparticles in the acceleration of the skin remodelling process showed promising results, subsequent studies might be useful.</p>","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"18 7","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/mna2.12171","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50119139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication of Circular Cross-Section Microchannels with 3-D Lattice Arrangement and Their Use as On-Off Valves","authors":"Kaori Uehara, Yutaka Hori, T. Ishigure","doi":"10.3390/micro3030043","DOIUrl":"https://doi.org/10.3390/micro3030043","url":null,"abstract":"In this paper, circular cross-section microchannels with 3-D lattice arrangements are designed and fabricated using the Mosquito method in order to construct on-off valves. The 3-D microchannels with on-off valves consist of two types of lines: the flow lines for chemical liquid flow and the control lines to activate the valves. We confirmed that both a circular cross-section and a PDMS with low elastic modulus used as the microchannel material contribute to a valve that can be closed with a lower pressure. Then, we demonstrated liquid flow to evaluate the functionality of the valve. Fluorescein solution was flown into a flow line. We found that the fluorescence intensity decreases at the intersection between the flow and control lines when the flow line is closed by the inflation of the control line, experimentally confirming the functionality of the valve microchannels fabricated via the Mosquito method.","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"25 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80058445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biosynthesis of ZnO.Ag2O3 using aqueous extract of Haplophyllum obtusifolium: Characterization and cell toxicity activity against liver carcinoma cells","authors":"Majid Halimi Khalil Abad,&nbsp;Mohabat Nadaf,&nbsp;Mohammad Ehsan Taghavizadeh Yazdi","doi":"10.1049/mna2.12170","DOIUrl":"https://doi.org/10.1049/mna2.12170","url":null,"abstract":"<p>The zinc oxide-silver oxide nanocomposite (ZnO.Ag₂O₃ particles) was prepared by using an aqueous plant extract of <i>Haplophyllum obtusifolium</i> for the first time. Powder X-ray diffraction (PXRD), Fourier transforms spectroscopy (FTIR), field emission microscopy (FESEM), energy dispersive X-ray analysis (EDX), and transmission electron microscopy (TEM) were applied to analyze the structure, functional groups, morphology, and purity of the prepared nanocomposite. PXRD revealed the formulation of ZnO.Ag₂O₃ for the particles. The investigation of functional groups has demonstrated the presence of some carbonated impurities along with absorbed water in the composition of the ZnO.Ag₂O₃ nanocomposite. Morphologically, particles have formed a petal-like shape with different sizes. The EDX analysis also confirmed the composition of the prepared sample and the presence of 4.78% silver in the formula. Additionally, the TEM analysis revealed spherical and rectangular shapes with a particle size of 80.43 ± 46.73 nm. Moreover, the ZnO.Ag₂O₃ particles were used against cancer cells, which has shown synthesized NCs have a toxic effect against liver cancer cells in a concentration and time-dependent manner.</p>","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"18 6","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/mna2.12170","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50143600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selective Hydrodeoxygenation of Guaiacol to Cyclohexane over Ru-Catalysts Based on MFI Nanosheets","authors":"Dmitry E. Tsaplin, A. Sadovnikov, D. Ramazanov, D. Gorbunov, Valeriya Ryleeva, A. Maximov, Kaige Wang, E. Naranov","doi":"10.3390/micro3020042","DOIUrl":"https://doi.org/10.3390/micro3020042","url":null,"abstract":"Bio-oils derived from the pyrolysis of lignin-based biomass often contain a variety of oxygenated compounds, which can compromise their usefulness as a fuel. To improve the quality of bio-oil, catalytic hydrodeoxygenation (HDO) is a crucial step that removes oxygen from the oil in the form of water. In this study, we showed that MFI nanosheets are excellent supports for Ru-catalysts. We synthesized highly crystalline MFI nanosheets using a simple hydrothermal seeding procedure; the final material was obtained in 56 h of crystallization. We investigated the activity of Ru supported on different materials. Our findings indicated that Ru supported on hierarchical MFI demonstrated excellent activity in HDO of guaiacol. Our results demonstrated that Ru/ZNS-56 achieved nearly 100% selectivity towards cyclohexane under mild conditions (200 °C, 50 bar H2, 1 h).","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"33 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88733794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"F2 Laser-Induced Micro-Reticulated Structural Changes of Amorphous Carbon Thin Films","authors":"M. Okoshi","doi":"10.3390/micro3020041","DOIUrl":"https://doi.org/10.3390/micro3020041","url":null,"abstract":"Micro/nanoprocessing of materials using lasers is currently an active research topic. In that research, the choice of the laser to be used is critical, but the F2 laser, which has the shortest wavelength (157 nm) among commercially available lasers, has few research compared to its potential. In this paper, we discovered a new photochemical processing by using an F2 laser to irradiate an amorphous carbon thin film. The short wavelength and high photon energy of the F2 laser can photoexcite the surface of the thin film at high density and generate active oxygen atoms O(1D) by photodecomposition of atmospheric oxygen molecules. As a result, the optical change of the amorphous carbon thin film was induced without thickness reduction, and a micron-sized network-like, reticulated structural change was formed in the thin film surface after one month at the latest. The formed micron-sized reticulated structure was relatively swollen, and a graphitization occurred in the structure, observed by Raman spectroscopy. However, the structure was not observed when the laser irradiated area became smaller. This work has made it possible to form a micron-sized reticulated structure including carbon nanocrystals in an amorphous carbon, which is expected to further expand the applications of carbon materials.","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"57 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77699023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Three novel iridium (III) complexes containing double chiral atoms for organic light-emitting diodes","authors":"Gan Cheng,&nbsp;Jun-jian Lu,&nbsp;Li-Ya Zhu,&nbsp;Guangzhao Lu","doi":"10.1049/mna2.12169","DOIUrl":"https://doi.org/10.1049/mna2.12169","url":null,"abstract":"<p>Chiral iridium (III) complexes are very important for the preparation of circularly polarized organic diodes light-emitting diodes (CP-OLEDs). Three novel iridium (III) complexes, Ir(dnfppy)₂(Cl/pyrrole), Ir(dfppy)₂(dpp), and Ir(tfmqz)₂(sdpp), have been synthesized and characterized, respectively. These iridium (III) complexes emitted deep-blue, blue, and red photoluminescence with high quantum yields (Ir(dnfppy)₂(Cl/Pyrrole): λ_max = 447 nm, F = 62.4%; Ir(dfppy)₂(dpp): λ_max = 467 nm, F = 25%; Ir(tfmqz)₂(sdpp): λ_max = 609 nm, F = 73.7%). Compared with Ir(dnfppy)₂(Cl/pyrrole), the HOMO energy levels of Ir(dfppy)₂(dpp) and Ir(tfmqz)₂(sdpp) were calculated to be −5.71/−5.73 eV, and the LUMO energy levels were increased to be −2.75/−3.36 eV, respectively. The circular dichroism spectra of two pairs of the enantiomers for Ir(dfppy)₂(dpp) or Ir(tfmqz)₂(sdpp) displayed symmetry with opposite polarization between 300 and 600 nm. The maximum external quantum efficiency (EQE_max) of OLEDs based on Ir(tfmpqz)₂(sddp) was 13.8%, showing a relatively low efficiency roll-off with the EQE of 10.7% at 5000 cd/m².</p>","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"18 6","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/mna2.12169","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50130105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}