Pub Date : 2025-12-13DOI: 10.1021/acs.langmuir.5c04731
Cecilia Vasti,María Elisa Mariani,Mónica S Sánchez,Pablo E A Rodríguez,Gerardo D Fidelio
Parkinson's disease (PD) is an age-related disorder characterized by amyloid deposits of the 140-amino-acid protein α-synuclein (AS), which contribute to neuronal dysfunction and degeneration, leading to motor and cognitive impairments. AS fibrillation, the process by which the native soluble protein misfolds into insoluble cross-β-sheet fibrils, involves transient prefibrillar species with distinct biophysical features. In vitro evidence suggests that these oligomeric intermediates, rather than mature fibrils, are the primary pathogenic agents in neurodegenerative diseases. Initial studies demonstrated that AS fibril formation is inhibited upon binding to lipid vesicles containing GM1 ganglioside. Here, we report for the first time the effect of the oligosaccharide portion of GM1 on AS fibrillation under in vitro conditions. To assess the specific contribution of this hydrophilic headgroup, we synthesized the oligosaccharide moiety of GM1 (oligoGM1) and compared its effect with that of GM1 micelles. We show that oligoGM1 stimulates amyloid fibril formation, whereas GM1 reduces or inhibits AS aggregation in a lipid/protein ratio-dependent manner. AFM analysis revealed that fibrils formed in the presence of oligoGM1 were lower in height than control fibrils, and that structures compatible with AS oligomers accumulated in the presence of GM1. Using dot blotting and AFM, we further confirmed that GM1 promotes the formation of oligomeric AS species in vitro. ThT-based aggregation kinetics showed that AS aggregation in the presence of GM1 was markedly slower than with oligoGM1, supporting that oligoGM1 accelerates AS fibrillation. Finally, cytotoxicity assays in SH-SY5Y neuroblastoma cells demonstrated that oligomers generated in the presence of GM1 exhibited higher toxicity than AS fibrils formed in the absence or presence of oligoGM1. These findings highlight the importance of the hydrophobic lipid moiety of GM1 in modulating AS aggregation and support the emerging view that the extent of fibrillar amyloid deposition does not correlate directly with neurodegenerative disease pathogenesis.
{"title":"GM1 and OligoGM1 Drive Divergent α-Synuclein Aggregation Pathways.","authors":"Cecilia Vasti,María Elisa Mariani,Mónica S Sánchez,Pablo E A Rodríguez,Gerardo D Fidelio","doi":"10.1021/acs.langmuir.5c04731","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c04731","url":null,"abstract":"Parkinson's disease (PD) is an age-related disorder characterized by amyloid deposits of the 140-amino-acid protein α-synuclein (AS), which contribute to neuronal dysfunction and degeneration, leading to motor and cognitive impairments. AS fibrillation, the process by which the native soluble protein misfolds into insoluble cross-β-sheet fibrils, involves transient prefibrillar species with distinct biophysical features. In vitro evidence suggests that these oligomeric intermediates, rather than mature fibrils, are the primary pathogenic agents in neurodegenerative diseases. Initial studies demonstrated that AS fibril formation is inhibited upon binding to lipid vesicles containing GM1 ganglioside. Here, we report for the first time the effect of the oligosaccharide portion of GM1 on AS fibrillation under in vitro conditions. To assess the specific contribution of this hydrophilic headgroup, we synthesized the oligosaccharide moiety of GM1 (oligoGM1) and compared its effect with that of GM1 micelles. We show that oligoGM1 stimulates amyloid fibril formation, whereas GM1 reduces or inhibits AS aggregation in a lipid/protein ratio-dependent manner. AFM analysis revealed that fibrils formed in the presence of oligoGM1 were lower in height than control fibrils, and that structures compatible with AS oligomers accumulated in the presence of GM1. Using dot blotting and AFM, we further confirmed that GM1 promotes the formation of oligomeric AS species in vitro. ThT-based aggregation kinetics showed that AS aggregation in the presence of GM1 was markedly slower than with oligoGM1, supporting that oligoGM1 accelerates AS fibrillation. Finally, cytotoxicity assays in SH-SY5Y neuroblastoma cells demonstrated that oligomers generated in the presence of GM1 exhibited higher toxicity than AS fibrils formed in the absence or presence of oligoGM1. These findings highlight the importance of the hydrophobic lipid moiety of GM1 in modulating AS aggregation and support the emerging view that the extent of fibrillar amyloid deposition does not correlate directly with neurodegenerative disease pathogenesis.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"372 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145746680","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}
The structure and arrangement of the micropillar array in the micropillar capillary pump have a significant influence on its flow resistance and flow rate. Therefore, research and prediction of the conveying performance can provide valuable guidance for the design of the capillary pump. In this study, we designed a high-flux capillary pump using large-sized micropillars. The flow rate and resistance of the pump were investigated through numerical simulations under various arrangement patterns, with a fixed column height of 0.4 mm and minor axis lengths ranging from 0.1 to 0.75 mm. It is found that the performance of the capillary pump is different when the shape or arrangement of the micropillars is changed. Considering the resistance and flow rate, the pumping effect of rhomboid micropillars is the best. Compared with the capillary pump with low height and small-sized capillary columns, the flow resistance of the pump is small, and the flux can be increased by dozens of times, but the side friction resistance and front form drag between the fluid and the micropillars cannot be ignored. In this study, the dynamic formula considering the side friction resistance is derived, and the resistance prediction formula of the high-flux capillary pump is derived according to the simulation results.
{"title":"Dynamics of High-Flux Capillary Pump","authors":"Huan Yan, Weiwei Li, Jiali Liu, Yating Li, Nerisha Tuladhar, Hussain Sehar Muzaffar, Kenechukwu George UGWU, Shengping You, Xiaohui Yan, Taotao Fu","doi":"10.1021/acs.langmuir.5c04494","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c04494","url":null,"abstract":"The structure and arrangement of the micropillar array in the micropillar capillary pump have a significant influence on its flow resistance and flow rate. Therefore, research and prediction of the conveying performance can provide valuable guidance for the design of the capillary pump. In this study, we designed a high-flux capillary pump using large-sized micropillars. The flow rate and resistance of the pump were investigated through numerical simulations under various arrangement patterns, with a fixed column height of 0.4 mm and minor axis lengths ranging from 0.1 to 0.75 mm. It is found that the performance of the capillary pump is different when the shape or arrangement of the micropillars is changed. Considering the resistance and flow rate, the pumping effect of rhomboid micropillars is the best. Compared with the capillary pump with low height and small-sized capillary columns, the flow resistance of the pump is small, and the flux can be increased by dozens of times, but the side friction resistance and front form drag between the fluid and the micropillars cannot be ignored. In this study, the dynamic formula considering the side friction resistance is derived, and the resistance prediction formula of the high-flux capillary pump is derived according to the simulation results.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"175 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731824","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}
Pub Date : 2025-12-13DOI: 10.1021/acs.langmuir.5c05585
Guanzheng Zhuang, Qian Liu, Bin Xiao, Qingbin Xie, Jixing Fan, Wenxiao Fan, Peng Yuan, Dong Liu
Sepiolite, a fibrous clay mineral, is highly valued for its ability to form gel networks and control rheology in saline environments. However, the ion-specific effects governing this behavior are not fully understood. This study systematically investigates the influence of four common electrolytes (NaCl, KCl, CaCl2, and MgCl2) across a wide concentration range (10–4 to 1 mol/L) on the colloidal stability, microstructure, and rheological behaviors of 5 wt % sepiolite dispersions. While all dispersions remained macroscopically stable against sedimentation, their rheological properties, including viscosity, yield stress, and thixotropy, showed a nonmonotonic trend. These properties initially decreased at low salt concentrations due to electrical double layer compression and subsequent network weakening, followed by a partial recovery at higher concentrations driven by van der Waals-induced aggregation. Cryo-scanning electron microscopy visualized the corresponding microstructural transition from a fine fiber network to an aggregated structure. The effects were ion-specific: divalent cations (Ca2+, Mg2+) caused more significant changes than monovalent cations (Na+, K+), with K+ proving more effective at screening charge than Na+. Low-field nuclear magnetic resonance showed that the mobility of water confined within interparticle pores remained constant. These findings explain the system’s ability to retain water and maintain a gel-like structure despite microstructural changes. This work provides a framework that links ion-specific interactions to multiscale structural and rheological changes, offering insights into the formulation of sepiolite-based fluids.
{"title":"Beyond Salt Resistance: Ion-Specific Modulation of Microstructure and Rheology of Sepiolite Dispersions","authors":"Guanzheng Zhuang, Qian Liu, Bin Xiao, Qingbin Xie, Jixing Fan, Wenxiao Fan, Peng Yuan, Dong Liu","doi":"10.1021/acs.langmuir.5c05585","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c05585","url":null,"abstract":"Sepiolite, a fibrous clay mineral, is highly valued for its ability to form gel networks and control rheology in saline environments. However, the ion-specific effects governing this behavior are not fully understood. This study systematically investigates the influence of four common electrolytes (NaCl, KCl, CaCl<sub>2</sub>, and MgCl<sub>2</sub>) across a wide concentration range (10<sup>–4</sup> to 1 mol/L) on the colloidal stability, microstructure, and rheological behaviors of 5 wt % sepiolite dispersions. While all dispersions remained macroscopically stable against sedimentation, their rheological properties, including viscosity, yield stress, and thixotropy, showed a nonmonotonic trend. These properties initially decreased at low salt concentrations due to electrical double layer compression and subsequent network weakening, followed by a partial recovery at higher concentrations driven by van der Waals-induced aggregation. Cryo-scanning electron microscopy visualized the corresponding microstructural transition from a fine fiber network to an aggregated structure. The effects were ion-specific: divalent cations (Ca<sup>2+</sup>, Mg<sup>2+</sup>) caused more significant changes than monovalent cations (Na<sup>+</sup>, K<sup>+</sup>), with K<sup>+</sup> proving more effective at screening charge than Na<sup>+</sup>. Low-field nuclear magnetic resonance showed that the mobility of water confined within interparticle pores remained constant. These findings explain the system’s ability to retain water and maintain a gel-like structure despite microstructural changes. This work provides a framework that links ion-specific interactions to multiscale structural and rheological changes, offering insights into the formulation of sepiolite-based fluids.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"15 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731826","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}
Pub Date : 2025-12-12DOI: 10.1021/acs.langmuir.5c02908
Mina Omidiyan, Pooria Tajalli, Hung-Vu Tran, Supawitch Hoijang, T. Randall Lee
Hydrophobic surfaces are important in daily life and in industries, including antifouling coatings, self-cleaning surfaces, microfluidic devices, and medicine. Here, we report the preparation and study of a nanoscale hydrophobic coating based on self-assembled monolayers (SAMs) of a thiol-functionalized methacryloxypropyl T-structure siloxane adsorbate, HS(CH2)CH(CH3)COO(CH2)4Si[O(Si(CH3)2O)nSi(CH3)3]3 (MAPTSiSH). The siloxane adsorbate was characterized by 1H, 13C, and COSY nuclear magnetic resonance spectroscopy. The resulting MAPTSiSH SAMs were characterized by ellipsometry, X-ray photoelectron spectroscopy (XPS), and polarization modulation infrared reflection–absorption spectroscopy (PM-IRRAS). Importantly, comparison of the hydrophobic properties of the SAMs derived from MAPTSiSH with its polymeric analogue, polydimethylsiloxane (PDMS), using contact-angle measurements over a broad set of probe liquids showed comparable surface wettability. Thus, the new siloxane-terminated SAMs serve as nanoscale mimics of hydrophobic PDMS surfaces and can be used to investigate the interfacial properties of industrially important PDMS without interference from surface reconstruction.
{"title":"Siloxane-Terminated Self-Assembled Monolayers for Mimicking Nanoscale Hydrophobic Polydimethylsiloxane Surfaces","authors":"Mina Omidiyan, Pooria Tajalli, Hung-Vu Tran, Supawitch Hoijang, T. Randall Lee","doi":"10.1021/acs.langmuir.5c02908","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c02908","url":null,"abstract":"Hydrophobic surfaces are important in daily life and in industries, including antifouling coatings, self-cleaning surfaces, microfluidic devices, and medicine. Here, we report the preparation and study of a nanoscale hydrophobic coating based on self-assembled monolayers (SAMs) of a thiol-functionalized methacryloxypropyl T-structure siloxane adsorbate, HS(CH<sub>2</sub>)CH(CH<sub>3</sub>)COO(CH<sub>2</sub>)<sub>4</sub>Si[O(Si(CH<sub>3</sub>)<sub>2</sub>O)<sub><i>n</i></sub>Si(CH<sub>3</sub>)<sub>3</sub>]<sub>3</sub> (MAPTSiSH). The siloxane adsorbate was characterized by <sup>1</sup>H, <sup>13</sup>C, and COSY nuclear magnetic resonance spectroscopy. The resulting MAPTSiSH SAMs were characterized by ellipsometry, X-ray photoelectron spectroscopy (XPS), and polarization modulation infrared reflection–absorption spectroscopy (PM-IRRAS). Importantly, comparison of the hydrophobic properties of the SAMs derived from MAPTSiSH with its polymeric analogue, polydimethylsiloxane (PDMS), using contact-angle measurements over a broad set of probe liquids showed comparable surface wettability. Thus, the new siloxane-terminated SAMs serve as nanoscale mimics of hydrophobic PDMS surfaces and can be used to investigate the interfacial properties of industrially important PDMS without interference from surface reconstruction.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"74 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145728699","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}
Metal–organic framework (MOF)-derived materials have attracted growing interest for wastewater treatment, owing to their tunable compositions and structural versatility. In this study, bimetallic cerium/copper benzene-1,3,5-tricarboxylate (Ce/Cu-BTC) nanofibers were synthesized at room temperature using sodium-BTC (Na-BTC) as the organic linker, followed by carbonization to obtain a Cu-doped CeO2/C hybrid material (denoted as Ce/Cu-BTC-C). The adsorption performance of both Ce/Cu-BTC and Ce/Cu-BTC-C toward Congo red (CR) and methyl blue (MB) was systematically evaluated. The Ce/Cu-BTC-C adsorbent exhibited markedly enhanced adsorption capacities and reached 1460.4 mg·g–1 for CR and 1906.9 mg·g–1 for MB, approximately 18.4- and 17.7-fold higher than those of the pristine Ce/Cu-BTC precursor (79.4 mg·g–1 and 107.6 mg·g–1, respectively). The significant improvement is attributed to carbonization-induced structural rearrangement and the increased exposure of redox-active Ce/Cu sites, as confirmed by XPS analysis. Kinetic results indicate that CR adsorption follows a pseudo-first-order model, whereas MB adsorption fits a pseudo-second-order model, consistent with distinct interaction strengths. The Ce/Cu-BTC-C adsorbent also demonstrated good reusability, retaining over 85% of its initial adsorption capacity after five successive regeneration cycles. Overall, this work provides an effective room-temperature synthetic route for producing MOF-derived metal-oxide/carbon hybrids with strong potential for organic dye removal.
{"title":"Carbonized Ce/Cu Metal–Organic Framework-Derived Porous Nanorods for High-Performance Adsorption of Organic Pollutants","authors":"Zhuoran Wang, Tianyu Xie, Dan Liang, Hui Liu, Jia Yang, Ping Cheng","doi":"10.1021/acs.langmuir.5c05366","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c05366","url":null,"abstract":"Metal–organic framework (MOF)-derived materials have attracted growing interest for wastewater treatment, owing to their tunable compositions and structural versatility. In this study, bimetallic cerium/copper benzene-1,3,5-tricarboxylate (Ce/Cu-BTC) nanofibers were synthesized at room temperature using sodium-BTC (Na-BTC) as the organic linker, followed by carbonization to obtain a Cu-doped CeO<sub>2</sub>/C hybrid material (denoted as Ce/Cu-BTC-C). The adsorption performance of both Ce/Cu-BTC and Ce/Cu-BTC-C toward Congo red (CR) and methyl blue (MB) was systematically evaluated. The Ce/Cu-BTC-C adsorbent exhibited markedly enhanced adsorption capacities and reached 1460.4 mg·g<sup>–1</sup> for CR and 1906.9 mg·g<sup>–1</sup> for MB, approximately 18.4- and 17.7-fold higher than those of the pristine Ce/Cu-BTC precursor (79.4 mg·g<sup>–1</sup> and 107.6 mg·g<sup>–1</sup>, respectively). The significant improvement is attributed to carbonization-induced structural rearrangement and the increased exposure of redox-active Ce/Cu sites, as confirmed by XPS analysis. Kinetic results indicate that CR adsorption follows a pseudo-first-order model, whereas MB adsorption fits a pseudo-second-order model, consistent with distinct interaction strengths. The Ce/Cu-BTC-C adsorbent also demonstrated good reusability, retaining over 85% of its initial adsorption capacity after five successive regeneration cycles. Overall, this work provides an effective room-temperature synthetic route for producing MOF-derived metal-oxide/carbon hybrids with strong potential for organic dye removal.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"10 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145728702","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}
Pub Date : 2025-12-12DOI: 10.1021/acs.langmuir.5c04791
Shengnan Wang, Yujia Wang, Yanling Yang, Jielong Luo, Shuangyu Li, Jiaqi Liu, Yan Ma, Shu Wang, Zhi Li
Fabricating flexible sensors with natural materials requires exquisite design and appropriate methods. In this study, a natural flat silk cocoon (FSC) was used as a flexible substrate for fabricating the piezoresistive pressure sensor. Supporting degumming was first applied to acquire sufficient internal space, and then, PPy was evenly coated on the FSC through in situ polymerization. This well-distributed coating of PPy on the surface and inside the FSC endows the assembled flexible pressure sensor with a high sensitivity (0.0633 kPa–1 in the 0–31 kPa range, 0.0228 kPa–1 in the 31–145 kPa range) and excellent durability (1100 cycles). This fabricated sensor is also able to respond quickly to changes in external pressure (response/recovery time of 130 ms/80 ms). Based on the excellent sensing performance and stability, this fabricated sensor can be applied to the fields of human motion monitoring, object recognition, and information transmission. The pressure sensor based on the natural FSC will receive more attention in the field of flexible wearable electronics.
{"title":"Flexible Piezoresistive Sensors Based on PPy Particles Encapsulating Natural Flat Silkworm Cocoons","authors":"Shengnan Wang, Yujia Wang, Yanling Yang, Jielong Luo, Shuangyu Li, Jiaqi Liu, Yan Ma, Shu Wang, Zhi Li","doi":"10.1021/acs.langmuir.5c04791","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c04791","url":null,"abstract":"Fabricating flexible sensors with natural materials requires exquisite design and appropriate methods. In this study, a natural flat silk cocoon (FSC) was used as a flexible substrate for fabricating the piezoresistive pressure sensor. Supporting degumming was first applied to acquire sufficient internal space, and then, PPy was evenly coated on the FSC through in situ polymerization. This well-distributed coating of PPy on the surface and inside the FSC endows the assembled flexible pressure sensor with a high sensitivity (0.0633 kPa<sup>–1</sup> in the 0–31 kPa range, 0.0228 kPa<sup>–1</sup> in the 31–145 kPa range) and excellent durability (1100 cycles). This fabricated sensor is also able to respond quickly to changes in external pressure (response/recovery time of 130 ms/80 ms). Based on the excellent sensing performance and stability, this fabricated sensor can be applied to the fields of human motion monitoring, object recognition, and information transmission. The pressure sensor based on the natural FSC will receive more attention in the field of flexible wearable electronics.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"29 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145729198","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}
Pub Date : 2025-12-12DOI: 10.1021/acs.langmuir.5c04906
Zhuoer Chen,Xingying Mou,Qingqing Yang,Yaning Liang,Ying Yang,Tao Le
With the advancement of aptamer, an increasing number of SELEX methods have been developed. However, not all methods can effectively and efficiently enrich aptamer sequences. Recent studies have shown that GO-SELEX and Gold-SELEX methods barely enrich adenosine aptamers, likely due to the adsorption of adenosine on the surfaces of GO and AuNPs. In this study, we used density functional theory to investigate the adsorption behavior and strength of adenine, the nucleobase of adenosine, on Au clusters, GO clusters, and rGO clusters. Adenine exhibited the highest adsorption energy on Au clusters at -1.3676 eV, followed by GO at -0.6146 eV, and the weakest on rGO at -0.5966 eV. Furthermore, by analyzing Mayer bond order, charge transfer, IGMH, and energy decomposition analysis, we determined that adenine interacts with Au clusters mainly through coordination bonds, Au-π interactions, and van der Waals forces; with GO clusters via hydrogen bonding, π-π stacking, and van der Waals forces; and with rGO clusters through π-π stacking and van der Waals forces. We find that adenine adsorption is strongest on Au clusters, weaker on GO, and weakest on rGO. This suggests that during SELEX, adenosine strongly adsorbs to the substrate, making it largely unavailable in solution to perform its selective role, thereby causing the failure in aptamer enrichment. These findings indicate that the interaction between the target and the SELEX substrate significantly affects SELEX efficiency. We recommend that future studies thoroughly consider such interactions.
{"title":"DFT Reveals Adenine Adsorption on Graphene Oxide and AuNPs: A Potential Reason for Failure in Aptamer Selection.","authors":"Zhuoer Chen,Xingying Mou,Qingqing Yang,Yaning Liang,Ying Yang,Tao Le","doi":"10.1021/acs.langmuir.5c04906","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c04906","url":null,"abstract":"With the advancement of aptamer, an increasing number of SELEX methods have been developed. However, not all methods can effectively and efficiently enrich aptamer sequences. Recent studies have shown that GO-SELEX and Gold-SELEX methods barely enrich adenosine aptamers, likely due to the adsorption of adenosine on the surfaces of GO and AuNPs. In this study, we used density functional theory to investigate the adsorption behavior and strength of adenine, the nucleobase of adenosine, on Au clusters, GO clusters, and rGO clusters. Adenine exhibited the highest adsorption energy on Au clusters at -1.3676 eV, followed by GO at -0.6146 eV, and the weakest on rGO at -0.5966 eV. Furthermore, by analyzing Mayer bond order, charge transfer, IGMH, and energy decomposition analysis, we determined that adenine interacts with Au clusters mainly through coordination bonds, Au-π interactions, and van der Waals forces; with GO clusters via hydrogen bonding, π-π stacking, and van der Waals forces; and with rGO clusters through π-π stacking and van der Waals forces. We find that adenine adsorption is strongest on Au clusters, weaker on GO, and weakest on rGO. This suggests that during SELEX, adenosine strongly adsorbs to the substrate, making it largely unavailable in solution to perform its selective role, thereby causing the failure in aptamer enrichment. These findings indicate that the interaction between the target and the SELEX substrate significantly affects SELEX efficiency. We recommend that future studies thoroughly consider such interactions.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"1 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145728634","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}
Pub Date : 2025-12-12DOI: 10.1021/acs.langmuir.5c04978
Mehdi Shafiei Aporvari, Sabareesh K. P. Velu, Ali-Reza Moradi, Emine Ulku Saritas
The bending dynamics of microscopic filaments play a crucial role in various mechanical and biological processes. While thermal fluctuations typically have a minor effect, active fluctuations can provide sufficient mechanical energy to alter bending deformations in these systems. In this work, we investigate how active noise influences the bending dynamics of a self-assembled chain of magnetic particles at a curved liquid–air interface in the presence of swimming E. coli bacteria. We analyze the bending behavior of semiflexible chains under a lateral gravitational force and compare their response in passive and active baths. In a passive bath, the chain remains bent, fluctuating slightly around its deformed configuration due to thermal noise. However, in an active bath, strong bacterial activity suppresses the average bending deformation, causing the chain to fluctuate around a nearly straight configuration. These findings highlight the impact of active fluctuations on self-assembled microstructures and demonstrate a simple yet effective approach to studying the mechanical dynamics of microscopic filaments.
{"title":"Bending Dynamics of Magnetic Filaments at a Curved Bacterial Bath Interface","authors":"Mehdi Shafiei Aporvari, Sabareesh K. P. Velu, Ali-Reza Moradi, Emine Ulku Saritas","doi":"10.1021/acs.langmuir.5c04978","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c04978","url":null,"abstract":"The bending dynamics of microscopic filaments play a crucial role in various mechanical and biological processes. While thermal fluctuations typically have a minor effect, active fluctuations can provide sufficient mechanical energy to alter bending deformations in these systems. In this work, we investigate how active noise influences the bending dynamics of a self-assembled chain of magnetic particles at a curved liquid–air interface in the presence of swimming <i>E. coli</i> bacteria. We analyze the bending behavior of semiflexible chains under a lateral gravitational force and compare their response in passive and active baths. In a passive bath, the chain remains bent, fluctuating slightly around its deformed configuration due to thermal noise. However, in an active bath, strong bacterial activity suppresses the average bending deformation, causing the chain to fluctuate around a nearly straight configuration. These findings highlight the impact of active fluctuations on self-assembled microstructures and demonstrate a simple yet effective approach to studying the mechanical dynamics of microscopic filaments.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"1 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731829","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}
Pub Date : 2025-12-12DOI: 10.1021/acs.langmuir.5c05054
Jonathan Quinson
Advances in nanotechnologies rely on bulletproof synthetic protocols of nanomaterials. Bringing breakthroughs from fundamental nanoscience to real-life solutions requires cost-efficient and scalable strategies. Sustainability is not only driving modern societies but also increasingly shaping modern research, opening a range of opportunities as well as calling for new mindsets. This perspective suggests how to navigate and address in a timely manner all of these challenges at the same time by questioning established synthetic protocols of nanomaterials. In particular, the development of so-called surfactant-free colloidal syntheses of metal nanoparticles is a promising area of research, opening seldom explored avenues to comply with the principle of green and sustainable chemistry, to develop a new understanding of nanoparticle formation, and ultimately lead to improved nanomaterials and technologies.
{"title":"Questioning Established Protocols for New and More Sustainable Syntheses of Nanomaterials","authors":"Jonathan Quinson","doi":"10.1021/acs.langmuir.5c05054","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c05054","url":null,"abstract":"Advances in nanotechnologies rely on bulletproof synthetic protocols of nanomaterials. Bringing breakthroughs from fundamental nanoscience to real-life solutions requires cost-efficient and scalable strategies. Sustainability is not only driving modern societies but also increasingly shaping modern research, opening a range of opportunities as well as calling for new mindsets. This perspective suggests how to navigate and address in a timely manner all of these challenges at the same time by questioning established synthetic protocols of nanomaterials. In particular, the development of so-called surfactant-free colloidal syntheses of metal nanoparticles is a promising area of research, opening seldom explored avenues to comply with the principle of g<i>reen</i> and s<i>ustainable</i> chemistry, to develop a new understanding of nanoparticle formation, and ultimately lead to improved nanomaterials and technologies.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"32 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145729200","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}
Pub Date : 2025-12-12DOI: 10.1021/acs.langmuir.5c05172
Sonam,Neetu Goel
The present study proposes to comprehensively investigate the adsorption of toxic cyanide gases (HCN, CNF, CNCl, CNBr, and NCCN) on pristine and transition-metal (TM)-decorated CrS2 monolayers using van der Waals-corrected density functional theory. The weak adsorption capability of pristine CrS2 renders it unsuitable for use as a gas sensor; therefore, the monolayer was decorated with TMs, Mn, and Fe. Among the plausible decoration sites, TMs prefer to bind on the TCr site of the CrS2. The energetic stability of the modified monolayers is ensured by high negative values of binding energies, i.e., -5.530 eV for Mn and -5.358 eV for Fe-CrS2. The Mn and Fe decoration significantly improves the surface activity of the intrinsic CrS2 by reducing the band gap (0.080 eV for Mn and 0.610 eV for Fe) and work function (4.945 eV for Mn and 5.173 eV for Fe). Compared with pristine CrS2, the gas adsorption energy of the modified monolayers is greatly improved, and the adsorption distance is enormously reduced, indicating that modification of the monolayer with the TMs enhances the gas sensitivity of CrS2 for toxic cyanide gases. The adsorption energy order is CNBr > CNF > NCCN > CNCl > HCN and NCCN > CNBr > CNF > CNCl > HCN for Mn and Fe-CrS2 monolayers, respectively. The adsorption effects of the target gases were compared and analyzed from the perspectives of the change of band gap, charge density difference, energy band structures, and partial density of states plots. The efficacy of the decorated monolayers for gas sensing was assessed in terms of work function, recovery time, and sensitivity measurements. The comparative analysis revealed that the Mn-CrS2 exhibits high adsorption strength and hence prolonged recovery times for the cyanide gases, signifying its potential as an effective adsorbent. On the contrary, the Fe-CrS2 monolayer shows optimum adsorption strength and faster recovery behavior, emerging as a reusable gas sensor. Overall, this study provides a theoretical framework and opens up new avenues for the design and experimental investigation of high-performance CrS2-based gas sensors to detect hazardous cyanide gases.
{"title":"Adsorption and Sensing of Cyanide Gases over Transition Metal (Mn and Fe)-Decorated CrS2 Monolayers: Insights from DFT and AIMD Simulations.","authors":" Sonam,Neetu Goel","doi":"10.1021/acs.langmuir.5c05172","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c05172","url":null,"abstract":"The present study proposes to comprehensively investigate the adsorption of toxic cyanide gases (HCN, CNF, CNCl, CNBr, and NCCN) on pristine and transition-metal (TM)-decorated CrS2 monolayers using van der Waals-corrected density functional theory. The weak adsorption capability of pristine CrS2 renders it unsuitable for use as a gas sensor; therefore, the monolayer was decorated with TMs, Mn, and Fe. Among the plausible decoration sites, TMs prefer to bind on the TCr site of the CrS2. The energetic stability of the modified monolayers is ensured by high negative values of binding energies, i.e., -5.530 eV for Mn and -5.358 eV for Fe-CrS2. The Mn and Fe decoration significantly improves the surface activity of the intrinsic CrS2 by reducing the band gap (0.080 eV for Mn and 0.610 eV for Fe) and work function (4.945 eV for Mn and 5.173 eV for Fe). Compared with pristine CrS2, the gas adsorption energy of the modified monolayers is greatly improved, and the adsorption distance is enormously reduced, indicating that modification of the monolayer with the TMs enhances the gas sensitivity of CrS2 for toxic cyanide gases. The adsorption energy order is CNBr > CNF > NCCN > CNCl > HCN and NCCN > CNBr > CNF > CNCl > HCN for Mn and Fe-CrS2 monolayers, respectively. The adsorption effects of the target gases were compared and analyzed from the perspectives of the change of band gap, charge density difference, energy band structures, and partial density of states plots. The efficacy of the decorated monolayers for gas sensing was assessed in terms of work function, recovery time, and sensitivity measurements. The comparative analysis revealed that the Mn-CrS2 exhibits high adsorption strength and hence prolonged recovery times for the cyanide gases, signifying its potential as an effective adsorbent. On the contrary, the Fe-CrS2 monolayer shows optimum adsorption strength and faster recovery behavior, emerging as a reusable gas sensor. Overall, this study provides a theoretical framework and opens up new avenues for the design and experimental investigation of high-performance CrS2-based gas sensors to detect hazardous cyanide gases.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"111 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145728636","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}
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