Micro & Nano Letters最新文献

{"title":"Matrix Effect of Properties of Au, ZnO and Eu2O3: Silica, Titania and Alumina Matrices","authors":"Carlos Díaz, O. Cifuentes-Vaca, M. Valenzuela","doi":"10.3390/micro3030049","DOIUrl":"https://doi.org/10.3390/micro3030049","url":null,"abstract":"The composites Au/SiO2, Au/TiO2, Au/Al2O3, ZnO/TiO2, ZnO/TiO2, ZnO/Al2O3 and Eu2O3/SiO2, Eu2O3/TiO2 and Eu2O3/Al2O3 were prepared using a solid-state method. The effect of the polymer precursors was investigated using two precursor polymers, Chitosan and Poly(styrene-co-4vinylpyridine), (PS-co-4-PVP) in the M/MxLy•Chitosan//M’xO’y as well as M/MxLy•PS-co-4-PVP//M’xO’y with M’xO’y = SiO2, TiO2 and Al2O3. The effects on the particle size and morphology were observed. The new composites were characterized using X-ray powder diffraction, SEM-EDS mapping and HRTEM analysis. The distribution of the metallic nanoparticles as well as the metal oxide nanoparticles inside the matrices depend on the matrix. Marked optical and photocatalytic effects of the Au, ZnO and Eu2O3 inside the SiO2, TiO2 and Al2O3 matrices are expected. An experiment is in course.","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"142 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88557185","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":"Highly Sensitive Sensor for the Determination of Riboflavin Using Thionine Coated Cadmium Selenide Quantum Dots Modified Graphite Electrode","authors":"A. Kalaivani, R. Suresh Babu, S. Sriman Narayanan","doi":"10.3390/micro3030048","DOIUrl":"https://doi.org/10.3390/micro3030048","url":null,"abstract":"In this paper, the electrochemical non-enzymatic detection of Riboflavin (RF) was proposed based on its catalytic reduction in a Thionine-coated Cadmium Selenide Quantum dots (TH@CdSe QDs)-modified paraffin wax-impregnated graphite electrode (PIGE) that was prepared using a novel approach. The synthesized TH@CdSe QDs were confirmed by UV-Vis spectroscopy, Confocal Raman Microscopy and High Resolution Transmission Electron Microscopy (HRTEM) studies. The electrochemical response of the TH@CdSe QDs-modified PIGE was studied by cyclic voltammetry. The voltammetric response of RF at the TH@CdSe QDs-modified PIGE showed higher current than the bare PIGE. Under optimum conditions, the electrocatalytic reduction currents of RF was found to be linearly related to its concentration over the range of 1.6 × 10−7 M to 1.4 × 10−4 M with a detection limit of 53 × 10−9 M (S/N = 3). The TH@CdSe QDs-modified PIGE was utilized as an amperometric sensor for the detection of RF in flow systems was performed by carrying out hydrodynamic and chronoamperometric experiments. The TH@CdSe QDs-modified PIGE showed very good stability and a longer shelf life. The applicability of the fabricated electrode was justified by the quantification of RF in commercial tablets.","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"48 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80626316","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":"Self-trigger and on-demand drug delivery system based on TiO2 nanotube arrays and its drug release behaviour","authors":"Tao Zhang,&nbsp;Nannan Liu,&nbsp;Chunling Xie,&nbsp;Xiufeng Xiao","doi":"10.1049/mna2.12173","DOIUrl":"https://doi.org/10.1049/mna2.12173","url":null,"abstract":"<p>The foundation of drug delivery systems based on titanium dioxide nanotube arrays has become an important means to increase the drug release performance of bone implantation materials. However, most of the conventional platforms have some disadvantages, such as large sudden release, uncontrollable, unintelligent, or not on-demand drug release process. Herein, the authors develop a unique self-triggering drug release system (SDDS), utilizing the advantages of 1-Tetradecanol (TD), such as decent biocompatibility, a phase transition temperature of 37.8°C, and the inexistence of complex chemical reaction process. The establishment of the platform can make a large amount of the anti-inflammatory drug (ibuprofen, IBU) released when the body or the affected area is inflamed, that is, when the temperature rises. Conversely, only a small amount or no drug is released when there is no inflammation, thereby achieving self-trigger release and on-demand release. The experimental results show that the system combines good self-trigger release properties, release sensitivity, drug release cycle, and low selectivity to the loaded drugs.</p>","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"18 8","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/mna2.12173","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50128492","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":"Microfluidic System for Cell Mixing and Particle Focusing Using Dean Flow Fractionation","authors":"Alexander Wiede, O. Stranik, A. Tannert, U. Neugebauer","doi":"10.3390/micro3030047","DOIUrl":"https://doi.org/10.3390/micro3030047","url":null,"abstract":"Recent developments in the field of additive manufacturing processes have led to tremendous technological progress and opened directions for the field of microfluidics. For instance, new flexible materials for 3D printing allow the substitution of polydimethylsiloxane (PDMS) in microfluidic prototype development. Three-dimensional-printed microfluidic components open new horizons, in particular for the automated handling of biological cells (e.g., eukaryotic cells or bacteria). Here, we demonstrate how passive mixing and passive separation processes of biological cells can be realized using 3D printing concepts for rapid prototyping. This technique facilitates low-cost experimental setups that are easy to modify and adopt for specific detection and diagnostic purposes. In particular, printing technologies based on fused deposition modeling and stereolithography are used and their realization is discussed. Additive technologies enable the fabrication of multiplication mixers, which overcome shortcomings of current pillar or curve-based techniques and enable efficient mixing, also of biological cells without affecting viability. Using standard microfluidic components and state-of-the art 3D printing technologies, we realize a separation system based on Dean flow fragmentation without the use of PDMS. In particular, we describe the use of a 3D-printed helix for winding a capillary for particle flow and a new chip design for particle separation at the outlet. We demonstrate the functionality of the system by successful isolation of ~12 µm-sized particles from a particle mixture containing large (~12 µm, typical size of eukaryotic cells) and small (~2 µm, typical size of bacteria or small yeasts) particles. Using this setup to separate eukaryotic cells from bacteria, we could prove that cell viability is not affected by passage through the microfluidic systems.","PeriodicalId":18398,"journal":{"name":"Micro & Nano Letters","volume":"282 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76255450","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":"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}