Nanoscale最新文献

{"title":"Controlling Raman enhancement in particle-aperture hybrid nanostructures by interlayer spacing","authors":"Kabusure Mogasa Kabusure, Petteri Piskunen, Jarkko J Saarinen, Veikko Linko, Tommi Kristian Hakala","doi":"10.1039/d4nr03648d","DOIUrl":"https://doi.org/10.1039/d4nr03648d","url":null,"abstract":"Here we show how surface-enhanced Raman spectroscopy (SERS) features can be fine-tuned in optically active substrates made of layered materials. To demonstrate this, we used DNA-assisted lithography (DALI) to create substrates with silver bowtie nanoparticle-aperture pairs and then coated the samples with rhodamine 6G (R6G) molecules. By varying the spacing between the aperture and particle layer, we were able to control the strength of the interlayer coupling between the plasmon resonances of the apertures and those of the underlying bowtie particles. The changes in the resulting field enhancements were confirmed by recording the Raman spectra of R6G from the substrates, and the experimental findings were supported with finite difference time domain (FDTD) simulations including reflection/extinction and near-field profiles.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"32 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142805202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Can structure influence hydrovoltaic energy generation? Insights from metallic 1T' and semiconducting 2H phases of MoS2","authors":"Suvigya Kaushik, Lalita Saini, Siva Nemala Sankar, Andrea Capasso, Li-Hsien Yeh, Gopinadhan Kalon","doi":"10.1039/d4nr02416h","DOIUrl":"https://doi.org/10.1039/d4nr02416h","url":null,"abstract":"Hydrovoltaic power generation from liquid water and ambient moisture has attracted considerable research efforts. However, there is still limited consensus on the optimal material properties required to maximize the power output. Here, we use laminates of two different phases of layered MoS2 – metallic 1T' and semiconducting 2H – as representative systems to investigate the critical influence of specific characteristics, such as hydrophilicity, interlayer channels, and structure, on the hydrovoltaic performance. The metallic 1T' phase was synthesized via a chemical exfoliation process and assembled into laminates, which can then be converted to the semiconducting 2H phase by thermal annealing. Under liquid water conditions, the 1T' laminates (having a channel size of ~6 Å) achieved a peak power density of 2.0 mW.m-2, significantly outperforming the 2H phase (lacking defined channels) that produced 2.4 μW.m-2. Our theoretical analysis suggests that energy generation in these hydrophilic materials primarily arises from electro-kinetic and surface diffusion mechanisms. These findings highlight the crucial role of phase-engineered MoS₂ and underscore the potential of 2D material laminates in advancing hydrovoltaic energy technologies.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"49 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142805206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strong enhancement of effective refractive index in structured colloids (TiO2@Silica)","authors":"Jessica Dipold, Niklaus Ursus Wetter, F. C. Marques, Aristide Dogariu, Ernesto Jimenez-Villar","doi":"10.1039/d4nr03626c","DOIUrl":"https://doi.org/10.1039/d4nr03626c","url":null,"abstract":"We use non-resonant Raman scattering to demonstrate a large enhancement of the effective refractive index experienced by Raman photons in a scattering medium comprising spatially-correlated photonic structures of core-shell TiO2@Silica scatterers mixed with silica nanoparticles and suspended in ethanol. We show that the high refractive index extends outside the physical boundary of the medium, which is attributed to the evanescent contributions of electromagnetic modes that are strongly localized within the medium. Notably, the effective enhancement can be observed even at very low intensities of Raman emission. This anomalous non-linear phenomenon could be explained by the successive polarization of valence electrons to virtual states induced by the strong photon correlations in the strongly localized electromagnetic modes. The enhancement of refractive index and its extension in the vicinity of medium’s interface provide new opportunities for controlling the electromagnetic fields in advanced photonic devices.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"67 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142809580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chiral Nanomaterials as Vaccine Adjuvants: A New Horizon in Immunotherapy","authors":"Kaixuan Wang, Hongshuang Wang, Xiaohui Wang","doi":"10.1039/d4nr03542a","DOIUrl":"https://doi.org/10.1039/d4nr03542a","url":null,"abstract":"Chiral nanomaterials are emerging as a promising class of vaccine adjuvants with the potential to significantly enhance vaccine efficacy, especially in the context of cancer immunotherapy. These nanomaterials can trigger enantioselective immune responses, enabling more precise and efficient vaccines. Their distinctive optical, electronic, and catalytic characteristics, along with the ability to be engineered with specific physical and chemical properties, make them highly suitable for next-generation vaccines development. Chiral nanomaterials can enhance antigen presentation, modulate the tumor microenvironment, and boost the efficacy of immune responses, particularly against complex diseases such as cancer. Nevertheless, significant challenges remain, such as ensuring the reproducibility of their synthesis, conducting thorough safety assessments, and gaining a deeper understanding of their interactions with the immune system. Continued research and development are crucial to unlocking the potential of chiral nanomaterials in vaccine technology, thus paving the way for more effective, targeted, and personalized immunotherapies.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"38 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142805091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Blister test to measure the out-of-plane shear modulus of few-layer graphene","authors":"Metehan Calis, Narasimha Boddeti, J. Scott Bunch","doi":"10.1039/d4nr04214j","DOIUrl":"https://doi.org/10.1039/d4nr04214j","url":null,"abstract":"We measure the out-of-plane shear modulus of few-layer graphene (FLG) by a blister test. During the test, we employed a monolayer molybdenum disulfide (MoS<small>₂</small>) membrane stacked onto FLG wells to facilitate the separation of FLG from the silicon oxide (SiO<small>_<em>x</em></small>) substrate. Using the deflection profile of the blister, we determine an average shear modulus <em>G</em> of 0.97 ± 0.15 GPa, and a free energy model incorporating the interfacial shear force is developed to calculate the adhesion energy between FLG and SiO<small>_<em>x</em></small> substrate. The experimental protocol can be extended to other two-dimensional (2D) materials and layered structures (LS) made from other materials (WS<small>₂</small>, hBN, <em>etc</em>.) to characterize their interlayer interactions. These results provide valuable insight into the mechanics of 2D nano devices which is important in designing more complex flexible electronic devices and nanoelectromechanical systems.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"77 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142805204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Percolative phase transition in few-layered MoSe2 Field-effect transistors using Co and Cr contacts","authors":"Roshan Padhan, Carlos Garcia, Sujit A. Kadam, Akshay Wali, Stephen McGill, Nihar Ranjan Pradhan, Ralu Divan, Anirudha Sumant, Daniel Rosenmann, Suzanne Miller","doi":"10.1039/d4nr03986f","DOIUrl":"https://doi.org/10.1039/d4nr03986f","url":null,"abstract":"The metal-to-insulator phase transition (MIT) in two-dimensional (2D) materials under the influence of a gating electric field has revealed interesting electronic behavior and the need for a deeper fundamental understanding of electron transport processes, while attracting great interest on the development of next-generation electronic and optoelectronic devices. Although the mechanism of the MIT in 2D semiconductors is a topic under debate in condensed matter physics, our work demonstrate the tunable percolative phase transition in few-layered MoSe<small>₂</small> field-effect transistors (FET)using different metallic contact materials. Here, we attempted to understand the MIT through temperature-dependent electronic transport measurements by tuning the carrier density in MoSe<small>₂</small> channel under the influence of applied gate voltage. In particular, we have examined this phenomenon using the conventional chromium (Cr) and ferromagnetic cobalt (Co) as two metal contacts. For both Cr and Co, our devices demonstrated an n-type behavior with a room-temperature field-effect mobility of 16 cm<small>²</small>V<small>^-1</small>s<small>^-1</small> for the device with Cr contacts and 92 cm<small>²</small>V<small>^-1</small>s<small>^-1</small>, respectively. At low temperature measurements of 50K, the mobilities increased significantly to 65 cm<small>²</small>V<small>^-1</small>s<small>^-1</small> for Cr and 394 cm<small>²</small>V<small>^-1</small>s<small>^-1</small> for the device with Co contacts. By fitting our experimental data to the percolative phase transition theory, the temperature-dependent conductivity data shows a transition from an insulating-to-metallic behavior at a bias of ~28 V for Cr contacts and ~20 V for Co contacts. This cross-over of the conductivity can be attributed to increasing carrier density as a function of gate bias in the temperature-dependent transfer characteristics. By extracting the critical exponents, we find that the transport behavior in device with Co contacts aligns closely with the 2D percolation theory. In contrast, the devices with Cr-contacted deviate significantly from the 2D limit at low temperatures.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"20 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increasing the dual-enzyme cascade biocatalysis efficiency and stability of metal–organic frameworks via one-step coimmobilization for visual detection of glucose","authors":"Haotian Chen, Zelong Yan, Jiangyue Ning, Xingyan Bao, Li Ding, Chang Shu","doi":"10.1039/d4nr04156a","DOIUrl":"https://doi.org/10.1039/d4nr04156a","url":null,"abstract":"In biosensing analysis, the activity of enzyme systems is limited by their fragility, and substrates catalyzed by monoenzymes tend to undergo spontaneous decomposition during ineffective mass transfer processes. In this study, we propose a novel strategy to encapsulate the glucose oxidase and horseradish peroxidase (GOx&amp;HRP) cascade catalytic system within the hydrophilic zeolite imidazole framework ZIF-90. By leveraging the specific pore structure of ZIF-90, we effectively immobilized GOx and HRP molecules in their three-dimensional conformations, which improved the catalytic activity of the encapsulated enzymes compared with that of free GOx and HRP in various harsh environments. Additionally, our strategy reduced the occurrence of ineffective mass transfer and enhanced the sensitivity of the biosensor through an enzyme cascade system. When this biosensor was applied to serum samples containing complex biological matrices, the degradation of GOx&amp;HRP by various proteases and the surface adsorption of diverse biomolecules were effectively prevented, thereby generating stable and reliable signals of glucose levels. The sensor shows remarkable sensitivity and selectivity for determining glucose concentrations ranging from 0 to 2.5 μg ml<small>⁻¹</small>, with a detection limit as low as 0.034 μg ml<small>⁻¹</small>. Furthermore, we developed a paper-based colorimetric sensor utilizing GOx&amp;HRP@ZIF-90 integrated with a smartphone platform for the visual detection of blood glucose.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"28 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-wavelength infrared metamaterial absorber with polarization and angle insensitivity using compact hybrid cylinder structures","authors":"Wenqian Zhang, Youxin Chen, Wei Jiang, Yan Miao, Qingkang Wang, Kaiyu Wu","doi":"10.1039/d4nr03707c","DOIUrl":"https://doi.org/10.1039/d4nr03707c","url":null,"abstract":"Broadband metamaterial absorbers in long wavelength infrared are promising in applications including thermal imaging, cloaking, radiative cooling and IR signature suppression. Although high absorption over long wavelength infrared has been extensively achieved, the challenge is to shrink both thickness and lateral footprint of unit absorbing structures. Here, a compact broadband long wavelength infrared metamaterial absorber consisting of multilayered Ge/Ti/Ge/SiO2 hybrid cylindrical structures, whose period and thickness are only ~1.2 μm, is proposed and realized. Various surface plasmon polaritons, localized surface plasmon resonances and their hybridization modes in long wavelength infrared, with polarization and angle insensitivity (at the range of 0~45°), are supported by this compact absorber whose absorbing unit is ultra-thin with small footprint, thanks to the strong redshift effect induced by high-k Ge. Paired with the loss provided by Ti and SiO2, an experimental spectral averaged absorption of 92.7% is achieved over 8 to 14 μm, agreeing well with simulation. The absorber can be facilely fabricated by a standard photolithographic process, not requiring lengthy and costly e-beam lithography. The absorber is promising in IR signature suppression indicated by preliminary results. The structural compactness and excellent long wavelength infrared absorbing capability grant the presented absorber good potential in various applications, especially those requiring miniaturization, integration and low heat capacity.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"9 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vivo synthesis of semiconductor nanoparticles in Azotobacter vinelandii for light-driven ammonia production","authors":"Gui-Min Kim, Yoojin Choi, Kyeong Rok Choi, Ilsong Lee, Jayeong Kim, Byunghyun Lee, Sang Yup Lee, Doh C. Lee","doi":"10.1039/d4nr02177k","DOIUrl":"https://doi.org/10.1039/d4nr02177k","url":null,"abstract":"Ammonia (NH<small>₃</small>) is an important commodity chemical used as an agricultural fertilizer and hydrogen-storage material. There has recently been much interest in developing an environmentally benign process for NH<small>₃</small> synthesis. Here, we report enhanced production of ammonia from diazotroph under light irradiation using hybrid composites of inorganic nanoparticles (NPs) and bacteria cells. The primary focus of this study lies in the intracellular biosynthesis of semiconductor NPs within <em>Azotobacter vinelandii</em>, a diazotroph, when bacteria cells are cultured in a medium containing precursor molecules. For example, enzymes in the bacterial cells, such as cystein desulfurase, convert cysteine (Cys) into precursors for cadmium sulfide (CdS) synthesis when supplied with CdCl<small>₂</small>. Photoexcited charge carriers in the biosynthesized NPs are transferred to nitrogen fixation enzymes, e.g., nitrogenase, facilitating the production of ammonium ions. Notably, the intracellular biosynthesis approach minimizes cell toxicity compared to extracellular synthesis due to the diminished generation of reactive oxygen species. The biohybrid system based on the <em>in vivo</em> approach results in five-fold increase of the ammonia production (0.45 mg g<small>_DCW</small><small>^-1</small> h<small>^-1</small>) compared to the case of diazotroph cells only (0.09 mg g<small>_DCW</small><small>^-1</small> h<small>^-1</small>).","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"61 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plasma-assisted destruction of polystyrene nanoplastics","authors":"Matthew R. Winburn, Maria F. Alvarado, Chin Li Cheung","doi":"10.1039/d4nr02498b","DOIUrl":"https://doi.org/10.1039/d4nr02498b","url":null,"abstract":"This study addresses the critical need for the effective removal of nanoplastics (1 nm to 1000 nm), which pose a significant environmental challenge due to their ease of entry into biological systems and poorly understood health impacts. We report our investigation of a plasma-assisted methodology with a falling film plasma reactor to destroy and remove 200 nm polystyrene nanoplastic particles from their aqueous solution. Using the nanoparticle tracking analysis, size exclusion chromatography, and total organic carbon (TOC) analysis, we examined the degradation kinetics of the nanoplastics upon plasma-assisted treatment. A nanoplastic removal rate of 98.4% by particle count was achieved in one hour of treatment. This rate increased to 99.3% after three hours of treatment, along with a 27.4% reduction in the TOC of the solution. The chromatography results indicate that the observed elimination of nanoplastic contaminants was likely through the production of short polystyrene oligomers with molecular weights roughly equivalent to those of two styrene units. The superior efficacy of the plasma-assisted methodology over traditional ozonation to destroy nanoplastics was also illustrated. Our results not only elucidate a hypothesized polystyrene radical decay mechanism but also demonstrate a potential and complementary approach for mitigating nanoplastic pollution in water purification strategies.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":"19 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}