Nanotechnology最新文献

{"title":"Oxidative stress-modifying effects of TiO₂nanoparticles with varying content of Ti³⁺(Ti²⁺) ions.","authors":"Viktor Kireev, Iryna Bespalova, Volodymyr Prokopiuk, Pavel Maksimchuk, Kateryna Hubenko, Ganna Grygorova, Lesya Demchenko, Anatolii Onishchenko, Liliya Tryfonyuk, Oleksandr Tomchuk, Anton Tkachenko, Svitlana Yefimova","doi":"10.1088/1361-6528/ad7e31","DOIUrl":"10.1088/1361-6528/ad7e31","url":null,"abstract":"<p><p>Nanoparticles (NPs) with reactive oxygen species (ROS)-regulating ability have recently attracted great attention as promising agents for nanomedicine. In the present study, we have analyzed the effects of TiO₂defect structure related to the presence of stoichiometric (Ti⁴⁺) and non-stoichiometric (Ti³⁺and Ti²⁺) titanium ions in the crystal lattice and TiO₂NPs aggregation ability on H₂O₂- and tert-butyl hydroperoxide (tBOOH)-induced ROS production in L929 cells. Synthesized TiO₂-A, TiO₂-B, and TiO₂-C NPs with varying Ti³⁺(Ti²⁺) content were characterized by x-ray powder diffraction, transmission electron microscopy, small-angle x-ray scattering, x-ray photoelectron spectroscopy, and optical spectroscopy methods. Given the role of ROS-mediated toxicity for metal oxide NPs, L929 cell viability and changes in the intracellular ROS levels in H₂O₂- and tBOOH-treated L929 cells incubated with TiO₂NPs have been evaluated. Our research shows that both the amount of non-stoichiometric Ti³⁺and Ti²⁺ions in the crystal lattice of TiO₂NPs and NPs aggregative behavior affect their catalytic activity, in particular, H₂O₂decomposition and, consequently, the efficiency of aggravating H₂O₂- and tBOOH-induced oxidative damage to L929 cells. TiO₂-A NPs reveal the strongest H₂O₂decomposition activity aligning with their less pronounced additional effects on H₂O₂-treated L929 cells due to the highest amount of Ti³⁺(Ti²⁺) ions. TiO₂-C NPs with smaller amounts of Ti³⁺ions and a tendency to aggregate in water solutions show lower antioxidant activity and, consequently, some elevation of the level of ROS in H2O2/tBOOH-treated L929 cells. Our findings suggest that synthesized TiO₂NPs capable of enhancing ROS generation at concentrations non-toxic for normal cells, which should be further investigated to assess their possible application in nanomedicine as ROS-regulating pharmaceutical agents.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142308178","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":"Ultrathin natural biotite crystals as a dielectric layer for van der Waals heterostructure applications.","authors":"Raphaela de Oliveira, Ana B Barbosa Yoshida, Cesar R Rabahi, Raul O Freitas, Verônica C Teixeira, Christiano J S de Matos, Yara Galvão Gobato, Ingrid D Barcelos, Alisson R Cadore","doi":"10.1088/1361-6528/ad7b3a","DOIUrl":"10.1088/1361-6528/ad7b3a","url":null,"abstract":"<p><p>Biotite, an iron-rich mineral belonging to the trioctahedral mica group, is a naturally abundant layered material (LM) exhibiting attractive electronic properties for application in nanodevices. Biotite stands out as a non-degradable LM under ambient conditions, featuring high-quality basal cleavage-a significant advantage for van der Waals heterostructure (vdWH) applications. In this work, we present the micro-mechanical exfoliation of biotite down to monolayers (1Ls), yielding ultrathin flakes with large areas and atomically flat surfaces. To identify and characterize the mineral, we conducted a multi-elemental analysis of biotite using energy-dispersive spectroscopy mapping. Additionally, synchrotron x-ray fluorescence and infrared nano-spectroscopy were employed to probe its iron content and vibrational signature in few-layer form, respectively, with sensitivity to the layer number. We have also observed good morphological and structural stability in time (up to 12 months) and no important changes in their physical properties after thermal annealing processes in ultrathin biotite flakes. Conductive atomic force microscopy evaluated its electrical capacity, revealing an electrical breakdown strength of approximately 1 V nm^-1. Finally, we explore the use of biotite as a substrate and encapsulating LM in vdWH applications. We have performed optical and magneto-optical measurements at low temperatures. We find that ultrathin biotite flakes work as a good substrate for 1L-MoSe₂, comparable to hexagonal boron nitride flakes, but it induces a small change of the 1L-MoSe₂<i>g</i>-factor values, most likely due to natural impurities on its crystal structure. Furthermore, our results show that biotite flakes are useful systems to protect sensitive LMs such as black phosphorus from degradation for up to 60 days in ambient air. Our study introduces biotite as a promising, cost-effective LM for the advancement of future ultrathin nanotechnologies.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142291765","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 dual-chambered microbial fuel cell with manganese dioxide nano-structured cathode for wastewater treatment.","authors":"Jayanthi Velayudhan, Sangeetha Subramanian","doi":"10.1088/1361-6528/ad7d7f","DOIUrl":"10.1088/1361-6528/ad7d7f","url":null,"abstract":"<p><p>Microbial fuel cells (MFCs) can generate electricity by breaking down organic molecules through sustainable bio-electrochemical processes and wastewater as an energy source. A novel approach to remediate wastewater containing selenite was studied utilizing a selenite-reducing mixed bacterial culture with a nano manganese oxide modified cathode in the MFCs. The modification enhanced electrochemical catalytic activity, extracellular electron transfer rate, chemical oxygen demand (COD) elimination efficiency, and coulombic efficiency. Scanning electron microscopy and energy dispersive x-rays analysis were used to examine a manganese dioxide-coated graphite cathode's surface morphology and chemical composition. The manganese dioxide-coated electrode generated up to 69% higher voltage with 150 ppm selenite concentration than the uncoated graphite electrode. The MFC removed up to 80% of the initial COD of 120 mg l^-1and achieved a maximum power density of 1.51 W m^-2. The study demonstrates that MFCs can effectively treat selenite-containing wastewater, and modifying the cathode can enhance energy production.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142291763","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-dimensional visualization of large-area, nanoscale topography measurements.","authors":"Eva Natinsky, Liam G Connolly, Michael Cullinan","doi":"10.1088/1361-6528/ad8165","DOIUrl":"https://doi.org/10.1088/1361-6528/ad8165","url":null,"abstract":"<p><p>High-resolution metrology is a critical area of development for nanoscale manufacturing, especially as it affects production throughput and fabrication quality. Atomic force microscopy (AFM) is one of the most popular tools for nanometrology, and high-resolution AFM often requires a significant time commitment and produces datasets of several million points. It is therefore critical for the development of data processing techniques to keep pace with the requirements of analyzing this type of data, and for these techniques to be portable as miniaturization in AFM is becoming more common. This work presents a data fitting algorithm designed for reducing the parameters of large-area data sets which utilizes well-established spline fitting techniques. In this paper we show that basis-spline fitting can be used to accurately represent large AFM data sets, including data sets with noisy data and sharp features, while achieving at least 90% parameter reduction in all test cases.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142350580","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 strategy to fabricate nanostructures with sub-nanometer line edge roughness.","authors":"Xin Zhuang, Yunsheng Deng, Yue Zhang, Kaimin Wang, Yulong Chen, Shiyang Gao, Jingfu Xu, Liqiu Wang, Xing Cheng","doi":"10.1088/1361-6528/ad6e88","DOIUrl":"10.1088/1361-6528/ad6e88","url":null,"abstract":"<p><p>Line edge roughness (LER) has been an important issue in the nanofabrication research, especially in integrated circuits. Despite numerous research studies has made efforts on achieving smaller LER value, a strategy to achieve sub-nanometer level LER still remains challenging due to inability to deposit energy with a profile of sub-nanometer LER. In this work, we introduce a strategy to fabricate structures with sub-nanometer LER, specifically, we use scanning helium ion beam to expose hydrogen silsesquioxane (HSQ) resist on thin SiNx membrane (∼20 nm) and present the 0.16 nm spatial imaging resolution based on this suspended membrane geometric construction, which is characterized by scanning transmission electron microscope (STEM). The suspended membrane serves as an energy filter of helium ion beam and due to the elimination of backscattering induced secondary electrons, we can systematically study the factors that influences the LER of the fabricated nanostructures. Furthermore, we explore the parameters including step size, designed exposure linewidth (DEL), delivered dosage and resist thickness and choosing the high contrast developer, the process window allows to fabricate lines with 0.2 nm LER is determined. AFM measurement and simulation work further reveal that at specific beam step size and DEL, the nanostructures with minimum LER can only be fabricated at specific resist thickness and dosage.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141976205","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":"Ultrathin nanocapacitor assembled via atomic layer deposition.","authors":"Javier Alonso Alonso Lopez Medina, J Ricardo Mejía-Salazar, William Orivaldo Faria Carvalho, Cesar Alberto Lopez Mercado, N Nedev, Faustino Reyes Gómez, Osvaldo Novais de Oliveira, M H Farías, Hugo Tiznado","doi":"10.1088/1361-6528/ad7f5c","DOIUrl":"https://doi.org/10.1088/1361-6528/ad7f5c","url":null,"abstract":"<p><p>We fabricated ultrathin metal - oxide - semiconductor (MOS) nanocapacitors using atomic layer deposition. The capacitors consist of a bilayer of Al2O3 and Y2O3 with a total thickness of ~10 nm, deposited on silicon substrate. The presence of the two materials, each slab being ~5 nm thick and uniform over a large area, was confirmed with Transmission Electron Microscopy and X-ray photoelectron spectroscopy (XPS). The capacitance in accumulation varied from 1.6 nF (at 1MHz) to ~2.8 nF (at 10 kHz), which is one to two orders of magnitude higher than other nanocapacitors. This high capacitance is attributed to the synergy between the dielectric properties of ultrathin Al2O3 and Y2O3 layers. The electrical properties of the nanocapacitor are stable within a wide range of temperatures, from 25 °C to 150 °C, as indicated by capacitance-voltage (C - V). Since the thickness-to-area ratio is negligible, the nanocapacitor could be simulated as a single parallel plate capacitor in COMSOL Multiphysics, with good agreement between experimental and simulation data. As a proof-of-concept we simulated a MOSFET device with the nanocapacitor gate dielectric, whose drain current is sufficiently high for micro and nanoelectronics integrated circuits, including for applications in sensing.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142350582","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":"Influence of UV irradiation on the luminescence properties of CsPbBr3 perovskite quantum dots and CsPbBr3 perovskite quantum dots/PVDF composite film - for white LED application.","authors":"Kamalarasan V, Chakrawarthy Venkateswaran","doi":"10.1088/1361-6528/ad7f62","DOIUrl":"https://doi.org/10.1088/1361-6528/ad7f62","url":null,"abstract":"<p><p>Perovskite quantum dots (QDs) have been widely investigated for their excellent properties such as high color purity in displays, tunable emission wavelength, and high photoluminescence quantum yield. For device applications, improving the stability is an area of interest. In this study, the effects of UV irradiation on the structural and luminescence properties of CsPbBr3 perovskite quantum dots (CPB QDs) excited at 365 nm were investigated. To overcome the effects of UV irradiation, a CPB QDs/PVDF composite flexible film was prepared. It exhibits high structural and optical stability under UV irradiation and emits a highly intense green color. The emission wavelength and intensity were observed for three years, and the stability of the temperature-dependent emission intensity up to 400 K has been reported. In addition, it is stable in water. A white LED, fabricated by integrating a blue LED with CPB QDs/PVDF composite film and red phosphor, produces bright natural white light [(CIE x, CIE y) = (0.3704, 0.3611), and CCT = 4177 K] with a color gamut area coverage of 86.4% of the standard NTSC (1953) color space.&#xD.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142350574","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":"Chemical vapor deposition growth of high-quality 2D ultrathin hexagonal CoSb crystals.","authors":"Jiaying Zhang, Yang Wang, Tian Li, Xinying Peng, He Wang, Donglin Ma","doi":"10.1088/1361-6528/ad77dd","DOIUrl":"10.1088/1361-6528/ad77dd","url":null,"abstract":"<p><p>CoSb has emerged as an important two-dimensional (2D) atomic crystal for its potential application in energy conversion and superconductivity. Controllable growth in terms of thickness and structural phase is necessary to elucidate its intrinsic properties at the 2D limit. Here we demonstrate the chemical vapour deposition of ultrathin hexagonal CoSb crystals on the mica substrate. The thickness could be controlled by growth time and the structural phase could be tuned by the precursor's supply ratio. Electrical transport measurements show that the chemical vapor deposition-grown ultrathin hexagonal CoSb is a good metal with non-Fermi liquid behavior. No apparent superconductivity has been observed down to 2.8 K.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142146006","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":"Sponge-shaped Au nanoparticles: a stand-alone metallic photocatalyst for driving the light-induced CO₂reduction reaction.","authors":"Ehsan Vahidzadeh, Harshitha Rajashekhar, Saralyn Riddell, Kazi M Alam, Damini Vrushabendrakumar, Navneet Kumar, Karthik Shankar","doi":"10.1088/1361-6528/ad6998","DOIUrl":"10.1088/1361-6528/ad6998","url":null,"abstract":"<p><p>Coinage metal nanoparticles (NPs) enable plasmonic catalysis by generating hot carriers that drive chemical reactions. Making NPs porous enhances the adsorption of reactant molecules. We present a dewetting and dealloying strategy to fabricate porous gold nanoparticles (Au-Sponge) and compare their CO₂photoreduction activity with respect to the conventional gold nanoisland (Au-Island) morphology. Porous gold nanoparticles exhibit an unusually broad and red-shifted plasmon resonance which is in agreement with the results of finite difference time domain (FDTD) simulations. The key insight of this work is that the multi-step reduction of CO₂driven by short-lived hot carriers generated by the d → s interband transition proceeds extremely quickly as evidenced by the generation of methane. A 3.8-fold enhancement in the photocatalytic performance is observed for the Au-Sponge in comparison to the Au-Island. Electrochemical cyclic voltammetry measurements confirm the 2.5-fold increase in the surface area and roughness factor of the Au-Sponge sample due to its porous nature. Our results indicate that the product yield is limited by the amount of surface adsorbates i.e. reactant-limited. Isotope-labeled mass spectrometry using¹³CO₂was used to confirm that the reaction product (¹³CH₄) originated from CO₂photoreduction. We also present the plasmon-mediated photocatalytic transformation of 4-aminothiophenol (PATP) into p,p'-dimercaptoazobenzene (DMAB) using Au-Sponge and Au-Island samples.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141860398","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":"Understanding disorder in monolayer graphene devices with gate-defined superlattices.","authors":"Vinay Kammarchedu, Derrick Butler, Asmaul Smitha Rashid, Aida Ebrahimi, Morteza Kayyalha","doi":"10.1088/1361-6528/ad7853","DOIUrl":"10.1088/1361-6528/ad7853","url":null,"abstract":"<p><p>Engineering superlattices (SLs)-which are spatially periodic potential landscapes for electrons-is an emerging approach for the realization of exotic properties, including superconductivity and correlated insulators, in two-dimensional materials. While moiré SL engineering has been a popular approach, nanopatterning is an attractive alternative offering control over the pattern and wavelength of the SL. However, the disorder arising in the system due to imperfect nanopatterning is seldom studied. Here, by creating a square lattice of nanoholes in the SiO₂dielectric layer using nanolithography, we study the SL potential and the disorder formed in hBN-graphene-hBN heterostructures. Specifically, we observe that while electrical transport shows distinct SL satellite peaks, the disorder of the device is significantly higher than graphene devices without any SL. We use finite-element simulations combined with a resistor network model to calculate the effects of this disorder on the transport properties of graphene. We consider three types of disorder: nanohole size variations, adjacent nanohole mergers, and nanohole vacancies. Comparing our experimental results with the model, we find that the disorder primarily originates from nanohole size variations rather than nanohole mergers in square SLs. We further confirm the validity of our model by comparing the results with quantum transport simulations. Our findings highlight the applicability of our simple framework to predict and engineer disorder in patterned SLs, specifically correlating variations in the resultant SL patterns to the observed disorder. Our combined experimental and theoretical results could serve as a valuable guide for optimizing nanofabrication processes to engineer disorder in nanopatterned SLs.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11409834/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142154633","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}