Langmuir最新文献

{"title":"Changes in Adsorption, Aggregation, and Diffusion Nature of Amyloid β on a Lipid Membrane in an Open System.","authors":"Akane Iida-Adachi, Hideki Nabika","doi":"10.1021/acs.langmuir.4c03663","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c03663","url":null,"abstract":"<p><p>The aggregation and accumulation of amyloid β 42 (Aβ42) peptides on the surface of brain cells is associated with Alzheimer's disease (AD); however, the underlying molecular mechanisms remain unclear. Herein, we used a unique brain-mimetic open system that continuously flows Aβ42 solution to analyze the initial aggregation and adsorptive nature of Aβ42 at physiological concentrations on the lipid membrane. The open system accelerated the adsorption and dimerization kinetics. Upon the addition of Aβ42, monomeric Aβ42 was dominant on the lipid bilayer surface in the closed system with no flow, whereas dimers and high-order oligomers were dominant in the open system. Closed and open systems exhibited different oligomerization kinetics, lipid-Aβ42 interactions, and diffusive properties of monomers and oligomers. These results indicate the specific adsorptive and diffusive nature of Aβ42 on the cell membrane. The open system may help in elucidating the molecular mechanisms underlying AD progression.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143062464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanistic Insights into the Corrosion Inhibition Performance of Eco-Friendly Nitrogen and Boron Co-Doped Carbon Dots for Mild Steel in a 15% HCl Solution.","authors":"Vandana Saraswat, Tarun Kanti Sarkar, Navjot Sandhu, Sahil Kohli, Manish Rawat, Kumari Keshar, Mahendra Yadav, Nargis Bano","doi":"10.1021/acs.langmuir.4c04672","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04672","url":null,"abstract":"<p><p>A novel and eco-friendly route to synthesize boron, nitrogen codoped carbon dots using aniline, citric acid, and boric acid as precursor materials has been used successfully to reduce mild steel corrosion. This report describes the detailed weight-loss experiments, electrochemical measurements, and surface morphology analysis conducted to explore the efficacy of B,N-CDs as a highly effective corrosion controller for mild steel (MS) protection in 15% hydrochloric acid (HCl). The findings specify that B,N-CDs significantly decreased the corrosion of MS and attained an inhibition capacity of up to 96.7% at 75 ppm. The protection of the MS surface occurs through the generation of a protective film through adsorption of the B,N-CDs. The corrosion inhibitor undergoes predominant physisorption, which is confirmed by the values of Δ<i>G</i>_ads. Electrochemical studies further established that B,N-CDs act as a mixed type corrosion inhibitor. Hence, the aforementioned carbon dots are both cathodic and anodic corrosion inhibitors for MS. The XPS of the inhibitors explained that it is of inorganic/organic hybrid nature of the protective film generated on the surface of the substrate. The findings represent a new highly effective corrosion inhibitor that outperforms most of the alternatives at lower concentrations.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143062519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beyond Surfactants: Janus Particles for Functional Interfaces and Coatings","authors":"Utsav Kumar Dey, Serkan Demirci, Ricardo Ortega, Thamer Rawah, Aneeba Chaudary, Fei Liu, Zhengtao Yang, Bingrui Huang, Shan Jiang","doi":"10.1021/acs.langmuir.4c04612","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04612","url":null,"abstract":"Janus particles (JPs), initially introduced as soft matter, have evolved into a distinctive class of materials that set them apart from traditional surfactants, dispersants, and block copolymers. This mini-review examines the similarities and differences between JPs and their molecular counterparts to elucidate the unique properties of JPs. Key studies on the assembly behavior of JPs in bulk phases and at interfaces are reviewed, highlighting their unique ability to form diverse, complex structures. The superior interfacial stability and tunable amphiphilicity of JPs make them highly effective emulsifiers and dispersants, particularly in emulsion polymerization systems. Beyond these applications, JPs demonstrate immense potential as coating materials, facilitating the development of eco-friendly, anti-icing, and antifouling coatings. A comparative discussion with zwitterionic polymers also highlights the distinctive advantages of each system. This review emphasizes that while JPs mimic some of the behaviors of small molecular surfactants, they also open doors to entirely new applications, making them indispensable as next-generation functional materials.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"27 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143056868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Propensity of Water Self-Ions at Air(Oil)–Water Interfaces Revealed by Deep Potential Molecular Dynamics with Enhanced Sampling","authors":"Pengchao Zhang, Xuefei Xu","doi":"10.1021/acs.langmuir.4c05004","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c05004","url":null,"abstract":"The preference of water self-ions (hydronium and hydroxide) toward air/oil–water interfaces is one of the hottest topics in water research due to its importance for understanding properties, phenomena, and reactions of interfaces. In this work, we performed enhanced-sampling molecular dynamics simulations based on state-of-the-art neural network potentials with approximate M06-2X accuracy to investigate the propensity of hydronium and hydroxide ions at air/oil(decane)–water interfaces, which can simultaneously describe well the water autoionization process forming these ions, the recombination of ions, and the ionic distribution along the normal distance to the interface by employing a set of appropriate Voronoi collective variables. A stable ionic double-layer distribution is observed near the air–water interface, while the distribution is different at oil–water interfaces, where hydronium tends to be repelled from the interface into the bulk water, whereas hydroxide, with an interfacial stabilization free energy of −0.6 kcal/mol, is enriched in the interfacial layer. Through simulations of oil droplets in water, we further reveal that the interfacial propensity of hydroxide ions is caused by the positive charge distribution of the oil–water interface contributed by hydrogens of the dangling OH bonds of the interfacial water layer and the outermost layer decane molecules lying flat on the droplet. The present results may aid in understanding the acid–base nature of water interfaces with wide applications.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"23 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143057339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of La₂O₃ Addition on CuO/CeO₂ Catalysts for the Water-Gas Shift Reaction.","authors":"Tatiana de Freitas Silva, José Mansur Assaf, Alessandra Fonseca Lucrédio, Cristhiane Guimarães Maciel Reis, Karina Arruda Almeida","doi":"10.1021/acs.langmuir.4c03606","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c03606","url":null,"abstract":"<p><p>CuO/CeO₂ and CuO/<i>x</i>CeO₂-<i>y</i>La₂O₃ catalysts, synthesized with varying CeO₂ and La₂O₃ molar ratios (1:1, 1:2, and 2:1), were prepared via the hydrothermal method and tested in the water-gas shift reaction (150-350 °C). La₂O₃ addition altered structural properties, reducing surface area and copper dispersion. XANES and in situ XRD confirmed metallic Cu species during reduction and reaction. Catalytic tests revealed CuO/CeO₂ excelled at low temperatures, while La₂O₃-doped catalysts, especially CuO/1CeO₂-1 La₂O₃, performed better at 250-350 °C. Stability tests showed La₂O₃-doped catalysts resisted deactivation and sintering better than CuO/CeO₂, even with CO₂ and H₂ in the feed.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143062513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanism of Norfloxacin Adsorption on Fe-BTC Derived from Acid Mine Drainage Sludge: Adsorption Experiments and Density Functional Theory Analysis.","authors":"Jiangnan Teng, Ran Teng, Jinyuan Jiang, Tong Hao, Haoyang Song, Wei Tan, Dongni Shi, Hongke Qin","doi":"10.1021/acs.langmuir.4c04941","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04941","url":null,"abstract":"<p><p>Acid mine drainage sludge (AMDS) can be utilized as a raw material to synthesize an efficient adsorbent through a more environmentally friendly approach for the removal of pollutants from water. In this study, iron ions were extracted from AMDS and then reacted with trimesic acid (BTC) under ambient conditions to synthesize Fe-BTC-<i>n</i>, iron-based metal-organic frameworks. These materials demonstrate an exceptionally high specific surface area and excellent chemical stability. Norfloxacin was applied as a model pollutant to assess the adsorption performance of the synthesized materials. Results indicated a maximum adsorption capacity of 280.84 mg/g at 298 K, an initial solution pH of 10, and an adsorbent dosage of 0.1 g/L. Characterization techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), N₂ adsorption-desorption isotherms, X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR), along with density functional theory (DFT) calculations, were employed to study the adsorption mechanisms of norfloxacin on the Fe-BTC surface. The adsorption mechanism was found to involve pore filling, electrostatic interactions, π-π stacking, and coordination interactions. Additionally, the adsorbent exhibited an excellent regeneration and desorption performance. This study offers a promising approach for converting AMDS into effective adsorbents for the treatment of antibiotic-contaminated wastewater, contributing to sustainable environmental development and remediation efforts.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143062517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid and Sensitive Detection of Mutations in SARS-CoV-2 by Surface-Enhanced Raman Spectroscopy.","authors":"Liping Chen, Xuanjiang Zeng, Fan Yang, Tao Yang, Yushi Chen, Yan Zhao, Xiaojun Luo, Yuanyuan Li","doi":"10.1021/acs.langmuir.4c04725","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04725","url":null,"abstract":"<p><p>Since the outbreak of the novel coronavirus (SARS-CoV-2), the world has suffered significant losses. At present, the pneumonia disease caused by SARS-CoV-2 virus has not been eliminated, and SARS-CoV-2 has a high mutation rate, and its variant strains also have a high prevalence rate, which has always threatened the health of all mankind. This study aims to develop a rapid and sensitive method to complement existing SARS-CoV-2 diagnostic tools by utilizing surface-enhanced Raman spectroscopy (SERS) for the direct detection of the intrinsic SERS signal from the S proteins of SARS-CoV-2 and its variants (Omicron and Delta) within 5 min using a portable Raman spectrometer. The linear range of S protein detection of Wild-type, Omicron and Delta variants ranged from 1.0 × 10^-7 to 1.0 × 10^-3 g·mL^-1, the limits of detection (LOD) were down to ∼10^-8 g·mL^-1 level. Our proposed method uses portable Raman spectrometer for direct detection, which is characterized by its simplicity, rapidity, portability, and wide applicability. It enables simultaneous detection of diverse mutated targets, thereby playing a pivotal role in the early diagnosis of viral diseases. Moreover, it holds promising prospects in the fields of chemistry, biology, and medicine.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143062528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Self-Assembly of Mycolic Acid in Water: Monolayer or Bilayer","authors":"Yogendra Kumar, Subhadip Basu, Dipankar Chatterji, Anirban Ghosh, Narayanaswamy Jayaraman, Prabal Kumar Maiti","doi":"10.1021/acs.langmuir.4c03743","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c03743","url":null,"abstract":"The enduring pathogenicity of <i>Mycobacterium tuberculosis</i> can be attributed to its lipid-rich cell wall, with mycolic acids (MAs) being a significant constituent. Different MAs’ fluidity and structural adaptability within the bacterial cell envelope significantly influence their physicochemical properties, operational capabilities, and pathogenic potential. Therefore, an accurate conformational representation of various MAs in aqueous media can provide insights into their potential role within the intricate structure of the bacterial cell wall. We have carried out MD simulations of MAs in an aqueous solution and shed light on various structural properties such as thickness, order parameters, area-per-MAs, conformational changes, and principle component (PC) in the single-component and mixture MAs monolayer. The different conformational populations in the monolayer were estimated using the distance-based analysis between the function groups represented as W, U, and Z conformations that lead to the fold of the MAs chain in the monolayer. Additionally, we have also simulated the mixture of alpha-MA (α-MA or AMA), methoxy-MA (MMA), and keto-MA (KMA) with 50.90% AMA, 36.36% MMA, and 12.72% KMA composition. The thickness of the MAs monolayer was observed to range from 5 to 7 nm with an average 820 kg/m³ density for α-MA, MMA, and KMA quantitative agreement with experimental results. The mero chain (long chain), consisting of a functional group at the proximal and distal positions, tends to fold and exhibit a more disordered phase than the short chain. The keto-MA showed the greatest WUZ total conformations (35.32%) with decreasing trend of eZ &gt; eU &gt; aU &gt; aZ folds in both single component and mixture. Our results are in quantitative agreement with the experimental observations. The sZ folds show the lowest conformational probability in monolayer assembly (0.75% in a single component and 1.1% in a mixture). However, eU and aU folds are most probable for AMA and MMA. One striking observation is the abundance of MA conformers beyond the known WUZ convention because of the wide range distribution of intramolecular distances and change in dihedral angles. From a thermodynamic perspective, all mycolic acid monolayers in this study within the microsecond-long simulation, MA molecules self-assembled, and the self-assembled monolayer was found to be stable. The conformation of MAs corresponding to lower free energy minima in the monolayer gives rise to tighter packing and a highly dense self-assembly. Such a highly packed assembly shows higher resistance for drug permeability. Therefore, we concluded that the monolayer formed by AMA will be more densely packed and may cause more resistance for the drug molecules.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"122 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143056866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nanoscale Prediction of Physical Water Reducer: Lubricating the Cement System by the Electric Field.","authors":"Huiwen Sun, Meng Wang, Dongshuai Hou, Pan Wang, Binmeng Chen, Jizhou Chen, Muhan Wang","doi":"10.1021/acs.langmuir.4c03316","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c03316","url":null,"abstract":"<p><p>Fluidity is a critical property of cement that significantly impacts the performance of cement paste in construction engineering. Fluidity is typically enhanced through the application of chemical additives (e.g., water-reducing agents). While chemical additives can enhance the fluidity and workability of cement, their drawbacks, such as cost and environmental impact, must be carefully considered. Most of the current research focuses on the use of chemical admixtures, while studies on physical alternatives remain limited. This study employs molecular dynamics (MD) simulation to propose an innovative strategy for improving the fluidity of cement slurry by applying an electric field, which acts as a physical water reducer. This research investigates the lubricating effect and underlying mechanism of the electric field on cement hydration product C-S-H particles at the nanoscale. This work demonstrates that increasing the electric field strength significantly reduces friction between cement particles, thereby improving fluidity when ions are present at the particle interface. Atomic-level structural analyses reveal that the electric field promotes a denser C-S-H structure and facilitates ion desorption from the C-S-H surface, which acts as a lubricant between particles. This study provides new insights into how an electric field can serve as a lubricant in cement systems, offering a promising approach to enhancing concrete fluidity without relying on chemical admixtures.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143062525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Zwitterionic Hydrogels: From Synthetic Design to Biomedical Applications.","authors":"Linran Gao, Andrew Varley, Hui Gao, Bowen Li, Xiaohui Li","doi":"10.1021/acs.langmuir.4c04788","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c04788","url":null,"abstract":"<p><p>Zwitterionic hydrogels have emerged as a highly promising class of biomaterials, attracting considerable attention due to their unique properties and diverse biomedical applications. Zwitterionic moieties, with their balanced positive and negative charges, endow hydrogels with exceptional hydration, resistance to nonspecific protein adsorption, and low immunogenicity due to their distinctive molecular structure. These properties facilitate various biomedical applications, such as medical device coatings, tissue engineering, drug delivery, and biosensing. This review explores the structure-property relationships in zwitterionic hydrogels, highlighting recent advances in their design principles, synthesis methods, structural characteristics, and biomedical applications. To meet the evolving and growing demand for the biomedical field, this review examines current challenges and explores future research directions for optimizing the multifunctional properties of zwitterionic hydrogels. As promising candidates for advanced biomaterials, zwitterionic hydrogels are poised to address critical challenges in biomedical applications, paving the way for improved therapeutic outcomes and broader applicability in healthcare.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143062533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}