1
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Noblet T, Busson B. Diagrammatic theory of magnetic and quadrupolar contributions to sum-frequency generation in composite systems. J Chem Phys 2024; 160:024704. [PMID: 38193549 DOI: 10.1063/5.0187520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 12/15/2023] [Indexed: 01/10/2024] Open
Abstract
Second-order nonlinear processes like Sum-Frequency Generation (SFG) are essentially defined in the electric dipolar approximation. However, when dealing with the SFG responses of bulk, big nanoparticles, highly symmetric objects, or chiral species, magnetic and quadrupolar contributions play a significant role in the process too. We extend the diagrammatic theory for linear and nonlinear optics to include these terms for single objects as well as for multipartite systems in interaction. Magnetic and quadrupolar quantities are introduced in the formalism as incoming fields, interaction intermediates, and sources of optical nonlinearity. New response functions and complex nonlinear processes are defined, and their symmetry properties are analyzed. This leads to a focus on several kinds of applications involving nanoscale coupled objects, symmetric molecular systems, and chiral materials, both in line with the existing literature and opening new possibilities for original complex systems.
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Affiliation(s)
- Thomas Noblet
- GRASP-Biophotonics, CESAM, University of Liege, Institute of Physics, Allée du 6 août 17, 4000 Liège, Belgium
| | - Bertrand Busson
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR 8000, 91405 Orsay, France
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2
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Golbek TW, Weidner T. Peptide Orientation Strongly Affected by the Nanoparticle Size as Revealed by Sum Frequency Scattering Spectroscopy. J Phys Chem Lett 2023; 14:9819-9823. [PMID: 37889607 DOI: 10.1021/acs.jpclett.3c01751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/29/2023]
Abstract
The orientation of proteins at interfaces has a profound effect on the function of proteins. For nanoparticles (NPs) in a biological environment, protein orientation determines the toxicity, function, and identity of the NP. Thus, understanding how proteins orientate at NP surfaces is a critical parameter in controlling NP biochemistry. While planar surfaces are often used to model NP interfaces for protein orientation studies, it has been shown recently that proteins can orient very differently on NP surfaces. This study uses sum frequency scattering vibrational spectroscopy of the model helical leucine-lysine (LK) peptide on NPs of different sizes to determine the cause for the orientation effects. The data show that, for low dielectric constant materials, the orientation of the helical LK peptide is a function of the coulombic forces between peptides across different particle volumes. This finding strongly suggests that flat model systems are only of limited use for determining protein orientation at NP interfaces and that charge interactions should be considered when designing medical NPs or assessing NP biocompatibility.
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Affiliation(s)
| | - Tobias Weidner
- Department of Chemistry, Aarhus University, 8000 Aarhus C, Denmark
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3
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Pullanchery S, Dupertuis N, Roesel T, Roke S. Liposomes and Lipid Droplets Display a Reversal of Charge-Induced Hydration Asymmetry. NANO LETTERS 2023; 23:9858-9864. [PMID: 37869786 PMCID: PMC10636888 DOI: 10.1021/acs.nanolett.3c02653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 10/03/2023] [Indexed: 10/24/2023]
Abstract
The unique properties of water are critical for life. Water molecules have been reported to hydrate cations and anions asymmetrically in bulk water, being a key element in the balance of biochemical interactions. We show here that this behavior extends to charged lipid nanoscale interfaces. Charge hydration asymmetry was investigated by using nonlinear light scattering methods on lipid nanodroplets and liposomes. Nanodroplets covered with negatively charged lipids induce strong water ordering, while droplets covered with positively charged lipids induce negligible water ordering. Surprisingly, this charge-induced hydration asymmetry is reversed around liposomes. This opposite behavior in charge hydration asymmetry is caused by a delicate balance of electrostatic and hydrogen-bonding interactions. These findings highlight the importance of not only the charge state but also the specific distribution of neutral and charged lipids in cellular membranes.
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Affiliation(s)
- Saranya Pullanchery
- Laboratory
for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI),
School of Engineering (STI), École
Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Nathan Dupertuis
- Laboratory
for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI),
School of Engineering (STI), École
Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Tereza Roesel
- Laboratory
for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI),
School of Engineering (STI), École
Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sylvie Roke
- Laboratory
for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI),
School of Engineering (STI), École
Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Institute
of Materials Science (IMX), École
Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Lausanne
Centre for Ultrafast Science (LACUS), École
Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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4
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Brown JB, Qian Y, Huang-Fu ZC, Zhang T, Wang H, Rao Y. In Situ Probing of the Surface Properties of Droplets in the Air. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023. [PMID: 37497860 DOI: 10.1021/acs.langmuir.3c00875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
Surface properties of nanodroplets and microdroplets are intertwined with their immense applicability in biology, medicine, production, catalysis, the environment, and the atmosphere. However, many means for analyzing droplets and their surfaces are destructive, non-interface-specific, not conducted under ambient conditions, require sample substrates, conducted ex situ, or a combination thereof. For these reasons, a technique for surface-selective in situ analyses under any condition is necessary. This feature article presents recent developments in second-order nonlinear optical scattering techniques for the in situ interfacial analysis of aerosol droplets in the air. First, we describe the abundant utilization of such droplets across industries and how their unique surface properties lead to their ubiquitous usage. Then, we describe the fundamental properties of droplets and their surfaces followed by common methods for their study. We next describe the fundamental principles of sum-frequency generation (SFG) spectroscopy, the Langmuir adsorption model, and how they are used together to describe adsorption processes at planar liquid and droplet surfaces. We also discuss the history of developments of second-order scattering from droplets suspended in dispersive media and introduce second-harmonic scattering (SHS) and sum-frequency scattering (SFS) spectroscopies. We then go on to outline the developments of SHS, electronic sum-frequency scattering (ESFS), and vibrational sum-frequency scattering (VSFS) from droplets in the air and discuss the fundamental insights about droplet surfaces that the techniques have provided. Finally, we describe some of the areas of nonlinear scattering from airborne droplets which need improvement as well as potential future directions and utilizations of SHS, ESFS, and VSFS throughout environmental systems, interfacial chemistry, and fundamental physics. The goal of this feature article is to spread knowledge about droplets and their unique surface properties as well as introduce second-order nonlinear scattering to a broad audience who may be unaware of recent progress and advancements in their applicability.
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Affiliation(s)
- Jesse B Brown
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322, United States
| | - Yuqin Qian
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322, United States
| | - Zhi-Chao Huang-Fu
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322, United States
| | - Tong Zhang
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322, United States
- Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Hui Wang
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322, United States
| | - Yi Rao
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322, United States
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5
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Golbek TW, Okur HI, Kulik S, Dedic J, Roke S, Weidner T. Lysozyme Interaction with Phospholipid Nanodroplets Probed by Sum Frequency Scattering Vibrational Spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:6447-6454. [PMID: 37125843 DOI: 10.1021/acs.langmuir.3c00276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
When a nanoparticle (NP) is introduced into a biological environment, its identity and interactions are immediately attributed to the dense layer of proteins that quickly covers the particle. The formation of this layer, dubbed the protein corona, is in general a combination of proteins interacting with the surface of the NP and a contest between other proteins for binding sites either at the surface of the NP or upon the dense layer. Despite the importance for surface engineering and drug development, the molecular mechanisms and structure behind interfacial biomolecule action have largely remained elusive. We use ultrafast sum frequency scattering (SFS) spectroscopy to determine the structure and the mode of action by which these biomolecules interact with and manipulate interfaces. The majority of work in the field of sum frequency generation has been done on flat model interfaces. This limits some important membrane properties such as membrane fluidity and dimensionality─important factors in biomolecule-membrane interactions. To move toward three-dimensional (3D) nanoscopic interfaces, we utilize SFS spectroscopy to interrogate the surface of 3D lipid monolayers, which can be used as a model lipid-based nanocarrier system. In this study, we have utilized SFS spectroscopy to follow the action of lysozyme. SFS spectra in the amide I region suggest that there is lysozyme at the interface and that the lysozyme induces an increased lipid monolayer order. The binding of lysozyme with the NP is demonstrated by an increase in acyl chain order determined by the ratio of the CH3 symmetric and CH2 symmetric peak amplitudes. Furthermore, the lipid headgroup orientation s-PO2- change strongly supports lysozyme insertion into the lipid layer causing lipid disruption and reorientation. Altogether, with SFS, we have made a huge stride toward understanding the binding and structure change of proteins within the protein corona.
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Affiliation(s)
| | - Halil I Okur
- Laboratory for Fundamental BioPhotonics (LBP), Institute of Bio-engineering (IBI), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Department of Chemistry and National Nanotechnology Research Center (UNAM), Bilkent University, 06800 Ankara, Turkey
| | - Sergey Kulik
- Laboratory for Fundamental BioPhotonics (LBP), Institute of Bio-engineering (IBI), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Jan Dedic
- Laboratory for Fundamental BioPhotonics (LBP), Institute of Bio-engineering (IBI), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sylvie Roke
- Laboratory for Fundamental BioPhotonics (LBP), Institute of Bio-engineering (IBI), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Institute of Materials Science and Engineering (IMX), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Tobias Weidner
- Department of Chemistry, Aarhus University, 8000 Aarhus C, Denmark
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6
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Chu B, Marchioro A, Roke S. Size dependence of second-harmonic scattering from nanoparticles: Disentangling surface and electrostatic contributions. J Chem Phys 2023; 158:094711. [PMID: 36889968 DOI: 10.1063/5.0135157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023] Open
Abstract
Polarimetric angle-resolved second-harmonic scattering (AR-SHS) is an all-optical tool enabling the study of unlabeled interfaces of nano-sized particles in an aqueous solution. As the second harmonic signal is modulated by interference between nonlinear contributions originating at the particle's surface and those originating in the bulk electrolyte solution due to the presence of a surface electrostatic field, the AR-SHS patterns give insight into the structure of the electrical double layer. The mathematical framework of AR-SHS has been previously established, in particular regarding changes in probing depth with ionic strength. However, other experimental factors may influence the AR-SHS patterns. Here, we calculate the size dependence of the surface and electrostatic geometric form factors for nonlinear scattering, together with their relative contribution to the AR-SHS patterns. We show that the electrostatic term is stronger in the forward scattering direction for smaller particle sizes, while the ratio of the electrostatic to surface terms decreases with increasing size. Besides this competing effect, the total AR-SHS signal intensity is also weighted by the particle's surface characteristics, given by the surface potential Φ0 and the second-order surface susceptibility χs,2 2. The weighting effect is experimentally demonstrated by comparing SiO2 particles of different sizes in NaCl and NaOH solutions of varying ionic strengths. For NaOH, the larger χs,2 2 values generated by deprotonation of surface silanol groups prevail over the electrostatic screening occurring at high ionic strengths; however, only for larger particle sizes. This study establishes a better connection between the AR-SHS patterns and surface properties and predicts trends for arbitrarily-sized particles.
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Affiliation(s)
- Bingxin Chu
- Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), École polytechnique fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Arianna Marchioro
- Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), École polytechnique fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sylvie Roke
- Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), École polytechnique fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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7
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Page EF, Blake MJ, Foley GA, Calhoun TR. Monitoring membranes: The exploration of biological bilayers with second harmonic generation. CHEMICAL PHYSICS REVIEWS 2022; 3:041307. [PMID: 36536669 PMCID: PMC9756348 DOI: 10.1063/5.0120888] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 11/03/2022] [Indexed: 12/23/2022]
Abstract
Nature's seemingly controlled chaos in heterogeneous two-dimensional cell membranes stands in stark contrast to the precise, often homogeneous, environment in an experimentalist's flask or carefully designed material system. Yet cell membranes can play a direct role, or serve as inspiration, in all fields of biology, chemistry, physics, and engineering. Our understanding of these ubiquitous structures continues to evolve despite over a century of study largely driven by the application of new technologies. Here, we review the insight afforded by second harmonic generation (SHG), a nonlinear optical technique. From potential measurements to adsorption and diffusion on both model and living systems, SHG complements existing techniques while presenting a large exploratory space for new discoveries.
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Affiliation(s)
- Eleanor F. Page
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Marea J. Blake
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Grant A. Foley
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Tessa R. Calhoun
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA
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8
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Golbek TW, Strunge K, Chatterley AS, Weidner T. Peptide Orientation at Emulsion Nanointerfaces Dramatically Different from Flat Surfaces. J Phys Chem Lett 2022; 13:10858-10862. [PMID: 36383054 DOI: 10.1021/acs.jpclett.2c02870] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The adsorption of protein to nanoparticles plays an important role in toxicity, food science, pharmaceutics, and biomaterial science. Understanding how proteins bind to nanophase surfaces is instrumental for understanding and, ultimately, controlling nanoparticle (NP) biochemistry. Techniques probing the adsorption of proteins at NP interfaces exist; however, these methods have been unable to determine the orientation and folding of proteins at these interfaces. For the first time, we probe in situ with sum frequency scattering vibrational spectroscopy the orientation of model leucine-lysine (LK) peptides adsorbed to NPs. The results show that both α-helical and β-strand LK peptides bind the particles in an upright orientation, in contrast to the flat orientation of LKs binding to planar surfaces. The different binding geometry is explained by Coulombic forces between peptides across the particle volume.
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Affiliation(s)
- Thaddeus W Golbek
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Kris Strunge
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Adam S Chatterley
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Tobias Weidner
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
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9
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Tran E, Jones KK, Cano GA, Moore FG, Scatena LF. Spectroscopic Studies of Zwitterionic DDAPS at Planar and Droplet Oil/Water Interfaces. J Phys Chem B 2022; 126:7720-7730. [PMID: 36166822 DOI: 10.1021/acs.jpcb.2c02664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Developing the knowledge on surfactant interfacial phenomena is highly valuable for the advancement of technological, commercial, and industrial products, as these applications often rely on interfacial and colloidal chemistry. Zwitterionic surfactants are a less toxic alternative to standard charged surfactants. With both positively charged quaternary ammonium and negatively charged sulfonate constituents, zwitterionic DDAPS can have diverse interfacial interactions with various coadditives. In this work, we investigate DDAPS adsorption to a planar oil/water interface and its stabilization of oil-in-water nanoemulsions. By studying both interfacial geometries with surface-specific, nonlinear spectroscopy, we gain deeper insights and a molecular perspective into DDAPS's behavior in the presence of various salts and cosurfactants. From an application standpoint, zwitterionic surfactants are often mixed with other chemicals or used in an environment with pre-existing chemicals (e.g., ocean water during oil remediation). Thus, it is important to understand how such coadditives alter DDAPS's behavior and its performance as an emulsifier. Our results show that DDAPS is nearly uninfluenced by coadditives at a planar oil/water interface, but the identical coadditives are crucial for DDAPS to form and stabilize nanoemulsions. Additionally, the surfactant packing properties vary between interfaces as well as coadditives, indicating that certain interactions with the DDAPS headgroup are stronger and play a greater role in tuning DDAPS's interfacial behavior.
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Affiliation(s)
- Emma Tran
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403, United States
| | - Konnor K Jones
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403, United States
| | - Gabrielle A Cano
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403, United States
| | - Frederick G Moore
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403, United States
| | - Lawrence F Scatena
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403, United States
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10
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Qian Y, Brown JB, Zhang T, Huang-Fu ZC, Rao Y. In Situ Detection of Chemical Compositions at Nanodroplet Surfaces and In-Nanodroplet Phases. J Phys Chem A 2022; 126:3758-3764. [PMID: 35667005 DOI: 10.1021/acs.jpca.2c03346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Small-volume nanodroplets play an increasingly common role in chemistry and biology. Such nanodroplets are believed to have unique chemical and physical properties at the interface between a droplet and its surrounding medium, however, they are underexamined. In this study, we present the novel technique of vibrational sum frequency scattering (VSFS) spectroscopy as an interface-specific, high-performance method for the in situ investigation of nanodroplets with sub-micron radii; as well as the droplet bulk through simultaneous hyper-Raman scattering (HRS) spectroscopy. We use laboratory-generated nanodroplets from aqueous alcohol solutions to demonstrate this technique's ability to separate the vibrational phenomena which take place at droplet surfaces from the underlying bulk phase. In addition, we systemically examine interfacial spectra of nanodroplets containing methanol, ethanol, 1-propanol, and 1-butanol through VSFS. Furthermore, we demonstrate interfacial differences between such nanodroplets and their analogous planar surfaces. The sensitivity of this technique to probe droplet surfaces with few-particle density at standard conditions validates VSFS as an analytical technique for the in situ investigation of small nanodroplets, providing breakthrough information about these species of ever-increasing relevance.
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Affiliation(s)
- Yuqin Qian
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322, United States
| | - Jesse B Brown
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322, United States
| | - Tong Zhang
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322, United States
| | - Zhi-Chao Huang-Fu
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322, United States
| | - Yi Rao
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322, United States
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11
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Schönfeldová T, Okur HI, Vezočnik V, Iacovache I, Cao C, Dal Peraro M, Maček P, Zuber B, Roke S. Ultrasensitive Label-Free Detection of Protein-Membrane Interaction Exemplified by Toxin-Liposome Insertion. J Phys Chem Lett 2022; 13:3197-3201. [PMID: 35377651 PMCID: PMC9014461 DOI: 10.1021/acs.jpclett.1c04011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 03/29/2022] [Indexed: 06/14/2023]
Abstract
Measuring the high-affinity binding of proteins to liposome membranes remains a challenge. Here, we show an ultrasensitive and direct detection of protein binding to liposome membranes using high throughput second harmonic scattering (SHS). Perfringolysin O (PFO), a pore-forming toxin, with a highly membrane selective insertion into cholesterol-rich membranes is used. PFO inserts only into liposomes with a cholesterol concentration >30%. Twenty mole-percent cholesterol results in neither SHS-signal deviation nor pore formation as seen by cryo-electron microscopy of PFO and liposomes. PFO inserts into cholesterol-rich membranes of large unilamellar vesicles in an aqueous solution with Kd = (1.5 ± 0.2) × 10-12 M. Our results demonstrate a promising approach to probe protein-membrane interactions below sub-picomolar concentrations in a label-free and noninvasive manner on 3D systems. More importantly, the volume of protein sample is ultrasmall (<10 μL). These findings enable the detection of low-abundance proteins and their interaction with membranes.
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Affiliation(s)
- T. Schönfeldová
- Laboratory
for fundamental BioPhotonics (LBP), Institute of Bio-engineering (IBI),
School of Engineering (STI), École
Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - H. I. Okur
- Laboratory
for fundamental BioPhotonics (LBP), Institute of Bio-engineering (IBI),
School of Engineering (STI), École
Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
- Department
of Chemistry and National Nanotechnology Research Center (UNAM), Bilkent University, 06800 Ankara, Turkey
| | - V. Vezočnik
- Department
of Biology, Biotechnical Faculty, University
of Ljubljana, Jamnikarjeva 101, Ljubljana 1000, Slovenia
| | - I. Iacovache
- Institute
of Anatomy, University of Bern, Baltzerstrasse 2, 3012 Bern, Switzerland
| | - C. Cao
- Institute
of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - M. Dal Peraro
- Institute
of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - P. Maček
- Department
of Biology, Biotechnical Faculty, University
of Ljubljana, Jamnikarjeva 101, Ljubljana 1000, Slovenia
| | - B. Zuber
- Institute
of Anatomy, University of Bern, Baltzerstrasse 2, 3012 Bern, Switzerland
| | - S. Roke
- Laboratory
for fundamental BioPhotonics (LBP), Institute of Bio-engineering (IBI),
School of Engineering (STI), École
Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
- Institute
of Materials Science (IMX) and Lausanne Centre for Ultrafast Science
(LACUS), École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
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12
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Glikman D, Braunschweig B. Nanoscale Effects on the Surfactant Adsorption and Interface Charging in Hexadecane/Water Emulsions. ACS NANO 2021; 15:20136-20147. [PMID: 34898170 DOI: 10.1021/acsnano.1c08038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Nanoscale properties at interfaces play a key role in the colloidal stability of emulsions and other soft matter materials where physical properties need to be controlled from the nano to macroscopically visible length scales. Our molecular level understanding of oil-water interfaces arises mostly from results at extended interfaces and the common view that emulsions are stabilized by a large number of surfactant molecules at the droplet's interface which, however, has been recently challenged. In this work, we show that the particle size and the curvature of oil droplets at the nanoscale is of great importance for the interface adsorption of dodecyl sulfate surfactants and possible counterion condensation at the charged hexadecane-water interface. Using second-harmonic scattering, we have studied the surface charge of oil droplets in nanoemulsions where we systematically varied the particle size R between 80 and 270 nm and demonstrate that the surface charge density σ changes drastically with size: For sizes >200 nm, σ is similar to what can be expected at flat extended interfaces, while σ is dramatically reduced by almost an order of magnitude when the particle size of the oil droplet is 80 nm. Using a theoretical approach that considers counterion condensation, we quantify the nanoscale effects on the change in surface charge with particle size and find excellent agreement with our experimental result. Modeling of the experimental results also implies that the charge per particle remains constant and depends on a critical balance of surfactant adsorption and ion condensation.
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Affiliation(s)
- Dana Glikman
- Institute of Physical Chemistry and Center for Soft Nanoscience, Westfälische Wilhelms-Universität Münster, Corrensstraße 28/30, 48149 Münster, Germany
| | - Björn Braunschweig
- Institute of Physical Chemistry and Center for Soft Nanoscience, Westfälische Wilhelms-Universität Münster, Corrensstraße 28/30, 48149 Münster, Germany
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13
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Pullanchery S, Kulik S, Rehl B, Hassanali A, Roke S. Charge transfer across C-H⋅⋅⋅O hydrogen bonds stabilizes oil droplets in water. Science 2021; 374:1366-1370. [PMID: 34882471 DOI: 10.1126/science.abj3007] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
[Figure: see text].
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Affiliation(s)
- Saranya Pullanchery
- Laboratory for Fundamental BioPhotonics, Institute of Bioengineering (IBI), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sergey Kulik
- Laboratory for Fundamental BioPhotonics, Institute of Bioengineering (IBI), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Benjamin Rehl
- Laboratory for Fundamental BioPhotonics, Institute of Bioengineering (IBI), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Ali Hassanali
- International Centre for Theoretical Physics, 34100 Trieste, Italy
| | - Sylvie Roke
- Laboratory for Fundamental BioPhotonics, Institute of Bioengineering (IBI), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.,Institute of Materials Science and Engineering (IMX), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.,Lausanne Centre for Ultrafast Science, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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14
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Xu B, Chen SL, Zhang Y, Li B, Yuan Q, Gan W. Evaluating the cross-membrane dynamics of a charged molecule on lipid films with different surface curvature. J Colloid Interface Sci 2021; 610:376-384. [PMID: 34923275 DOI: 10.1016/j.jcis.2021.12.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/27/2021] [Accepted: 12/04/2021] [Indexed: 11/25/2022]
Abstract
Does the curvature of a phospholipid membrane influence the permeability of the lipid bilayers? This is a question of great importance yet hard to answer. In this work the permeability of a positively charged rod like probing molecule (D289 dye) on the bilayers of DOPG lipid vesicles was investigated using angle resolved second harmonic generation method. It was revealed that the permeability of D289 on the surface of small vesicles with ∼ 100 nm diameter was notably lower than that on giant vesicles with ∼ 1000 nm diameter. With the increasing of temperature or the introducing of dimethyl sulfoxide (DMSO) in the solutions, the D289 permeability of the lipid bilayers was notably enhanced as expected, on both the small and the giant vesicles. Still, the D289 permeability of the lipid film with more curvature is lower than the relatively flat film in all these cases. This work demonstrated a general protocol for the investigating of surface permeability of lipid films with various curvature.
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Affiliation(s)
- Baomei Xu
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, and School of Science, Harbin Institute of Technology (Shenzhen), University Town, Shenzhen 518055, Guangdong, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang, China
| | - Shun-Li Chen
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structure Materials of Guangdong Province, Shantou University, Shantou 515063, Guangdong, China
| | - Yiru Zhang
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, and School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), University Town, Shenzhen 518055, Guangdong, China
| | - Bifei Li
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, and School of Science, Harbin Institute of Technology (Shenzhen), University Town, Shenzhen 518055, Guangdong, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang, China
| | - Qunhui Yuan
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, and School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), University Town, Shenzhen 518055, Guangdong, China
| | - Wei Gan
- Shenzhen Key Laboratory of Flexible Printed Electronics Technology, and School of Science, Harbin Institute of Technology (Shenzhen), University Town, Shenzhen 518055, Guangdong, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang, China.
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15
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Schönfeldová T, Piller P, Kovacik F, Pabst G, Okur HI, Roke S. Lipid Melting Transitions Involve Structural Redistribution of Interfacial Water. J Phys Chem B 2021; 125:12457-12465. [PMID: 34730965 PMCID: PMC8607985 DOI: 10.1021/acs.jpcb.1c06868] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 10/15/2021] [Indexed: 11/29/2022]
Abstract
Morphological and gel-to-liquid phase transitions of lipid membranes are generally considered to primarily depend on the structural motifs in the hydrophobic core of the bilayer. Structural changes in the aqueous headgroup phase are typically not considered, primarily because they are difficult to quantify. Here, we investigate structural changes of the hydration shells around large unilamellar vesicles (LUVs) in aqueous solution, using differential scanning calorimetry (DSC), and temperature-dependent ζ-potential and high-throughput angle-resolved second harmonic scattering measurements (AR-SHS). Varying the lipid composition from 1,2-dimyristoyl-sn-glycero-3-phosphocholine(DMPC) to 1,2-dimyristoyl-sn-glycero-3-phosphate (DMPA), to 1,2-dimyristoyl-sn-glycero-3-phospho-l-serine (DMPS), we observe surprisingly distinct behavior for the different systems that depend on the chemical composition of the hydrated headgroups. These differences involve changes in hydration following temperature-induced counterion redistribution, or changes in hydration following headgroup reorientation and Stern layer compression.
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Affiliation(s)
- Tereza Schönfeldová
- Laboratory
for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), Institute of Materials
Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Paulina Piller
- Institute
of Molecular Biosciences, Biophysics Division, University of Graz, NAWI Graz, Humboldtstrasse 50/III, Graz 8010, Austria
| | - Filip Kovacik
- Laboratory
for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), Institute of Materials
Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Georg Pabst
- Institute
of Molecular Biosciences, Biophysics Division, University of Graz, NAWI Graz, Humboldtstrasse 50/III, Graz 8010, Austria
| | - Halil I. Okur
- Laboratory
for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), Institute of Materials
Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Department
of Chemistry and National Nanotechnology Research Center (UNAM), Bilkent University, 06800 Ankara, Turkey
| | - Sylvie Roke
- Laboratory
for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), Institute of Materials
Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale
de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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16
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Le Breton G, Bonhomme O, Brevet PF, Benichou E, Loison C. First hyperpolarizability of water at the air-vapor interface: a QM/MM study questions standard experimental approximations. Phys Chem Chem Phys 2021; 23:24932-24941. [PMID: 34726679 DOI: 10.1039/d1cp02258j] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Surface Second-Harmonic Generation (S-SHG) experiments provide a unique approach to probe interfaces. One important issue for S-SHG is how to interpret the S-SHG intensities at the molecular level. Established frameworks commonly assume that each molecule emits light according to an average molecular hyperpolarizability tensor β(-2ω,ω,ω). However, for water molecules, this first hyperpolarizability is known to be extremely sensitive to their environment. We have investigated the molecular first hyperpolarizability of water molecules within the liquid-vapor interface, using a quantum description with explicit, inhomogeneous electrostatic embedding. The resulting average molecular first hyperpolarizability tensor depends on the distance relative to the interface, and it practically respects the Kleinman symmetry everywhere in the liquid. Within this numerical approach, based on the dipolar approximation, the water layer contributing to the Surface Second Harmonic Generation (S-SHG) intensity is less than a nanometer. The results reported here question standard interpretations based on a single, averaged hyperpolarizability for all molecules at the interface. Not only the molecular first hyperpolarizability tensor significantly depends on the distance relative to the interface, but it is also correlated to the molecular orientation. Such hyperpolarizability fluctuations may impact the S-SHG intensity emitted by an aqueous interface.
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Affiliation(s)
- Guillaume Le Breton
- University of Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Villeurbanne, France.
| | - Oriane Bonhomme
- University of Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Villeurbanne, France.
| | - Pierre-François Brevet
- University of Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Villeurbanne, France.
| | - Emmanuel Benichou
- University of Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Villeurbanne, France.
| | - Claire Loison
- University of Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Villeurbanne, France.
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17
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Windowless detection geometry for sum frequency scattering spectroscopy in the C-D and amide I regions. Biointerphases 2021; 16:011201. [PMID: 33706523 DOI: 10.1116/6.0000419] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Understanding the structure and chemistry of nanoscopic surfaces is an important challenge for biointerface sciences. Sum frequency scattering (SFS) spectroscopy can specifically probe the surfaces of nanoparticles, vesicles, liposomes, and other materials relevant to biomaterial research, and, as a vibrational spectroscopy method, it can provide molecular level information about the surface chemistry. SFS is particularly promising to probe the structure of proteins, and other biological molecules, at nanoparticle surfaces. Here, amide I spectra can provide information about protein folding and orientation, while spectra in the C-D and C-H stretching regions allow experiments to determine the mode of interaction between particle surfaces and proteins. Methods used currently employ a closed liquid cell or cuvette, which works extremely well for C-H and phosphate regions but is often impeded in the amide I and C-D regions by a strong background signal that originates from the window material of the sample cells. Here, we discuss a windowless geometry for collecting background-free and high-fidelity SFS spectra in the amide I and C-D regions. We demonstrate the improvement in spectra quality by comparing SFS spectra of unextruded, multilamellar vesicles in a sample cuvette with those recorded using the windowless geometry. The sample geometry we propose will enable new experiments using SFS as a probe for protein-particle interactions.
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18
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Boudjema L, Aarrass H, Assaf M, Morille M, Martin-Gassin G, Gassin PM. PySHS: Python Open Source Software for Second Harmonic Scattering. J Chem Inf Model 2020; 60:5912-5917. [PMID: 33085456 DOI: 10.1021/acs.jcim.0c00789] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The PySHS package is a new python open source software tool which simulates the second harmonic scattering (SHS) of different kinds of colloidal nano-objects in various experimental configurations. This package is able to compute polarizations resolved at a fixed scattered angle or angular distribution for different polarization configurations. This article presents the model implemented in the PySHS software and gives some computational examples. A comparison between computational results and experimental data concerning molecular dye intercalated inside liposomes membrane is presented to illustrate the possibilities with PySHS.
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Affiliation(s)
- Lotfi Boudjema
- ICGM, ENSCM, CNRS, Univ. Montpellier, 34095 Montpellier Cedex 5, France
| | - Hanna Aarrass
- ICGM, ENSCM, CNRS, Univ. Montpellier, 34095 Montpellier Cedex 5, France
| | - Marwa Assaf
- ICGM, ENSCM, CNRS, Univ. Montpellier, 34095 Montpellier Cedex 5, France
| | - Marie Morille
- ICGM, ENSCM, CNRS, Univ. Montpellier, 34095 Montpellier Cedex 5, France
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19
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Qian Y, Deng GH, Rao Y. In Situ Spectroscopic Probing of Polarity and Molecular Configuration at Aerosol Particle Surfaces. J Phys Chem Lett 2020; 11:6763-6771. [PMID: 32787224 DOI: 10.1021/acs.jpclett.0c02013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The growth of aerosol particles in the atmosphere is related to chemical reactions in the gas and particle phases and at aerosol particle surfaces. While research regarding the gas and particle phases of aerosols is well-documented, physical properties and chemical reactivities at aerosol particle surfaces have not been studied extensively but have long been recognized. In particular, in situ measurements of aerosol particle surfaces are just emerging. The main reason is a lack of suitable surface-specific analytical techniques for direct measurements of aerosol particles under ambient conditions. Here we develop in situ surface-specific electronic sum frequency scattering (ESFS) to directly identify spectroscopic behaviors of molecules at aerosol particle surfaces. As an example, we applied an ESFS probe, malachite green (MG). We examined electronic spectra of MG at aerosol particle surfaces and found that the polarity of the surfaces is less polar than that in bulk. Our quantitative orientational analysis shows that MG is orientated with a polar angle of 25°-35° at the spherical particle surfaces of aerosols. The adsorption free energy of MG at the aerosol surfaces was found to be -20.75 ± 0.32 kJ/mol, which is much lower than that at the air/water interface. These results provide new insights into aerosol particle surfaces for further understanding the formation of secondary organic aerosols in the atmosphere.
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Affiliation(s)
- Yuqin Qian
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322, United States
| | - Gang-Hua Deng
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322, United States
| | - Yi Rao
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322, United States
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20
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Smolentsev N, Roke S. Self-Assembly at Water Nanodroplet Interfaces Quantified with Nonlinear Light Scattering. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:9317-9322. [PMID: 32654491 DOI: 10.1021/acs.langmuir.0c01887] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The interfaces of water micro- and nanodroplets drive environmental, medical, catalytic, biological, and chemical biphasic processes. The interfacial droplet structure and electrostatics greatly determine the reactivity and efficiency of these processes. Droplet interfacial properties are elusive and generally inferred from bulk measurements and are therefore anything but exact. Here, we quantify the interfacial ordering of water and the electrostatic surface potential of nanoscale water droplets in an apolar liquid using angle-resolved polarimetric second-harmonic scattering. We also present a method to determine the amount of free charges in the hydrophobic phase, reaching a sensitivity that is 3 orders of magnitude better than conductivity measurements. Investigating the structural and surface electrostatic changes induced by AOT surfactant adsorption, we find that both the hydrogen bonding as well as the electrostatics strongly depend on the surfactant concentration. Above the critical micelle concentration, the interface mediates micelle self-assembly.
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Affiliation(s)
- N Smolentsev
- Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - S Roke
- Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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21
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Bischoff M, Biriukov D, Předota M, Roke S, Marchioro A. Surface Potential and Interfacial Water Order at the Amorphous TiO 2 Nanoparticle/Aqueous Interface. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2020; 124:10961-10974. [PMID: 35592180 PMCID: PMC9109959 DOI: 10.1021/acs.jpcc.0c01158] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/21/2020] [Indexed: 05/11/2023]
Abstract
Colloidal nanoparticles exhibit unique size-dependent properties differing from their bulk counterpart, which can be particularly relevant for catalytic applications. To optimize surface-mediated chemical reactions, the understanding of the microscopic structure of the nanoparticle-liquid interface is of paramount importance. Here we use polarimetric angle-resolved second harmonic scattering (AR-SHS) to determine surface potential values as well as interfacial water orientation of ∼100 nm diameter amorphous TiO2 nanoparticles dispersed in aqueous solutions, without any initial assumption on the distribution of interfacial charges. We find three regions of different behavior with increasing NaCl concentration. At very low ionic strengths (0-10 μM), the Na+ ions are preferentially adsorbed at the TiO2 surface as inner-sphere complexes. At low ionic strengths (10-100 μM), a distribution of counterions equivalent to a diffuse layer is observed, while at higher ionic strengths (>100 μM), an additional layer of hydrated condensed ions is formed. We find a similar behavior for TiO2 nanoparticles in solutions of different basic pH. Compared to identically sized SiO2 nanoparticles, the TiO2 interface has a higher affinity for Na+ ions, which we further confirm with molecular dynamics simulations. With its ability to monitor ion adsorption at the surface with micromolar sensitivity and changes in the surface potential, AR-SHS is a powerful tool to investigate interfacial properties in a variety of catalytic and photocatalytic applications.
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Affiliation(s)
- Marie Bischoff
- Laboratory
for fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI),
and Institute of Materials
Science (IMX), School of Engineering (STI), École polytechnique fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Denys Biriukov
- Institute
of Physics, Faculty of Science, University
of South Bohemia, 370 05 České Budějovice, Czech
Republic
| | - Milan Předota
- Institute
of Physics, Faculty of Science, University
of South Bohemia, 370 05 České Budějovice, Czech
Republic
| | - Sylvie Roke
- Laboratory
for fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI),
and Institute of Materials
Science (IMX), School of Engineering (STI), École polytechnique fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- E-mail:
| | - Arianna Marchioro
- Laboratory
for fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI),
and Institute of Materials
Science (IMX), School of Engineering (STI), École polytechnique fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- E-mail:
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22
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Carpenter AP, Altman RM, Tran E, Richmond GL. How Low Can You Go? Molecular Details of Low-Charge Nanoemulsion Surfaces. J Phys Chem B 2020; 124:4234-4245. [DOI: 10.1021/acs.jpcb.0c03293] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Andrew P. Carpenter
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97405, United States
| | - Rebecca M. Altman
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97405, United States
| | - Emma Tran
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97405, United States
| | - Geraldine L. Richmond
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97405, United States
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23
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Hosseinpour S, Roeters SJ, Bonn M, Peukert W, Woutersen S, Weidner T. Structure and Dynamics of Interfacial Peptides and Proteins from Vibrational Sum-Frequency Generation Spectroscopy. Chem Rev 2020; 120:3420-3465. [DOI: 10.1021/acs.chemrev.9b00410] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Saman Hosseinpour
- Institute of Particle Technology (LFG), Friedrich-Alexander-University Erlangen-Nürnberg (FAU), 91058 Erlangen, Germany
| | | | - Mischa Bonn
- Molecular Spectroscopy Department, Max Planck Institute for Polymer Research, 55128 Mainz, Germany
| | - Wolfgang Peukert
- Institute of Particle Technology (LFG), Friedrich-Alexander-University Erlangen-Nürnberg (FAU), 91058 Erlangen, Germany
| | - Sander Woutersen
- Van’t Hoff Institute for Molecular Sciences, University of Amsterdam, 1098 EP Amsterdam, The Netherlands
| | - Tobias Weidner
- Department of Chemistry, Aarhus University, 8000 Aarhus C, Denmark
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24
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Okur HI, Tarun OB, Roke S. Chemistry of Lipid Membranes from Models to Living Systems: A Perspective of Hydration, Surface Potential, Curvature, Confinement and Heterogeneity. J Am Chem Soc 2019; 141:12168-12181. [DOI: 10.1021/jacs.9b02820] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Halil I. Okur
- Laboratory for Fundamental BioPhotonics
(LBP), Institute of Bioengineering (IBI) and Institute of Materials
Science (IMX), School of Engineering (STI) and Lausanne Center for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Orly B. Tarun
- Laboratory for Fundamental BioPhotonics
(LBP), Institute of Bioengineering (IBI) and Institute of Materials
Science (IMX), School of Engineering (STI) and Lausanne Center for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sylvie Roke
- Laboratory for Fundamental BioPhotonics
(LBP), Institute of Bioengineering (IBI) and Institute of Materials
Science (IMX), School of Engineering (STI) and Lausanne Center for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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25
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Johansson PK, Castner DG. Vibrational Sum-Frequency Scattering as a Sensitive Approach to Detect Structural Changes in Collagen Fibers Treated with Surfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:7848-7857. [PMID: 31117724 PMCID: PMC6648693 DOI: 10.1021/acs.langmuir.9b00412] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Optimizing protocols so that the structure of the collagen fibers in the extracellular matrix remains intact during the decellularization process requires techniques with high structural sensitivity, especially for the surface region of the collagen fibers. Here, we demonstrate that vibrational sum-frequency scattering (SFS) spectroscopy in the protein-specific amide I region provides vibrational spectra and scattering patterns characteristic of protein fiber networks self-assembled in vitro from collagen type I, which are kept in aqueous environments during the analysis. At scattering angles away from the phase-matched direction, the relative strengths of various polarization combinations are highly reproducible, and changes in their ratios can be followed in real time during exposure to sodium dodecyl sulfate surfactant solutions. For the fibers in this work, a scattering angle of about 22° provided specificity for the surface region of the fibers, as it allowed monitoring of immediate structural changes during the surfactant exposure. With further development, we hypothesize that the information from the SFS characterization of collagen fibers may complement information from other techniques with sensitivity to the overall structure, such as second-harmonic generation imaging and infrared spectroscopy, and provide a more complete understanding of fiber molecular structures and interactions during exposure to various environments and conditions.
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Affiliation(s)
- Patrik K. Johansson
- National ESCA and Surface Analysis Center for Biomedical Problems, University of Washington, Seattle, 98195, United States
- Department of Bioengineering, University of Washington, Seattle, 98195, United States
- Corresponding Author ,
| | - David G. Castner
- National ESCA and Surface Analysis Center for Biomedical Problems, University of Washington, Seattle, 98195, United States
- Department of Bioengineering, University of Washington, Seattle, 98195, United States
- Department of Chemical Engineering, University of Washington, Seattle, 98195, United States
- Corresponding Author ,
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26
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Carpenter AP, Tran E, Altman RM, Richmond GL. Formation and surface-stabilizing contributions to bare nanoemulsions created with negligible surface charge. Proc Natl Acad Sci U S A 2019; 116:9214-9219. [PMID: 31019075 PMCID: PMC6511027 DOI: 10.1073/pnas.1900802116] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The stabilization of nanoemulsions, nanosized oil droplets dispersed in water, is commonly achieved through the addition of surfactants and polymers. However, nanoemulsions in the absence of emulsifiers have been observed to acquire a significant negative charge at their surface, which ultimately contributes to their stability. While the source of this negative charge is disputed to this day, its presence is taken as an inherent property of the aqueous-hydrophobic interface. This report provides a look at the molecular structure and bonding characteristics of bare aqueous-hydrophobic nanoemulsion interfaces. We report the creation of bare nanoemulsions with near zero surface charge, which are marginally stable for several days. The process of creating these low-charge nanoemulsions (LCNEs) required rigorous cleaning procedures and proper solvent storage conditions. Using vibrational sum-frequency scattering spectroscopy, we measure the structure and bonding of the interfacial aqueous and hydrophobic phases. The surfaces of these LCNE samples possess a measurable free OH vibration, not found in previous studies and indicative of a clean interface. Tuning the nanoemulsion charge through addition of anionic surfactants, modeling potential surface-active contaminants, we observe the free OH to disappear and a reorientation of the interfacial hydrophobic molecules at micromolar surfactant concentrations. Notably, the free OH vibration provides evidence for stronger dispersion interactions between water molecules and the hydrophobic phase at the LCNE surface compared with similar planar water-alkane interfaces. We propose the stronger bonding interactions, in addition to an ordered interfacial aqueous layer, contribute to the delayed droplet coalescence and subsequent phase separation.
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Affiliation(s)
- Andrew P Carpenter
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403
| | - Emma Tran
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403
| | - Rebecca M Altman
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403
| | - Geraldine L Richmond
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403
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27
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Zdrali E, Baer MD, Okur HI, Mundy CJ, Roke S. The Diverse Nature of Ion Speciation at the Nanoscale Hydrophobic/Water Interface. J Phys Chem B 2019; 123:2414-2423. [DOI: 10.1021/acs.jpcb.8b10207] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Evangelia Zdrali
- Laboratory for fundamental BioPhotonics, Institutes of Bioengineering and Materials Science and Engineering, School of Engineering, and Lausanne Centre for Ultrafast Science, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Marcel D. Baer
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Halil I. Okur
- Laboratory for fundamental BioPhotonics, Institutes of Bioengineering and Materials Science and Engineering, School of Engineering, and Lausanne Centre for Ultrafast Science, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Christopher J. Mundy
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Sylvie Roke
- Laboratory for fundamental BioPhotonics, Institutes of Bioengineering and Materials Science and Engineering, School of Engineering, and Lausanne Centre for Ultrafast Science, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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28
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Abstract
The principles, strengths and limitations of several nonlinear optical (NLO) methods for characterizing biological systems are reviewed. NLO methods encompass a wide range of approaches that can be used for real-time, in-situ characterization of biological systems, typically in a label-free mode. Multiphoton excitation fluorescence (MPEF) is widely used for high-quality imaging based on electronic transitions, but lacks interface specificity. Second harmonic generation (SHG) is a parametric process that has all the virtues of the two-photon version of MPEF, yielding a signal at twice the frequency of the excitation light, which provides interface specificity. Both SHG and MPEF can provide images with high structural contrast, but they typically lack molecular or chemical specificity. Other NLO methods such as coherent anti-Stokes Raman scattering (CARS) and stimulated Raman scattering (SRS) can provide high-sensitivity imaging with chemical information since Raman active vibrations are probed. However, CARS and SRS lack interface and surface specificity. A NLO method that provides both interface/surface specificity as well as molecular specificity is vibrational sum frequency generation (SFG) spectroscopy. Vibration modes that are both Raman and IR active are probed in the SFG process, providing the molecular specificity. SFG, like SHG, is a parametric process, which provides the interface and surface specificity. SFG is typically done in the reflection mode from planar samples. This has yielded rich and detailed information about the molecular structure of biomaterial interfaces and biomolecules interacting with their surfaces. However, 2-D systems have limitations for understanding the interactions of biomolecules and interfaces in the 3-D biological environment. The recent advances made in instrumentation and analysis methods for sum frequency scattering (SFS) now present the opportunity for SFS to be used to directly study biological solutions. By detecting the scattering at angles away from the phase-matched direction even centrosymmetric structures that are isotropic (e.g., spherical nanoparticles functionalized with self-assembled monolayers or biomolecules) can be probed. Often a combination of multiple NLO methods or a combination of a NLO method with other spectroscopic methods is required to obtain a full understanding of the molecular structure and surface chemistry of biomaterials and the biomolecules that interact with them. Using the right combination methods provides a powerful approach for characterizing biological materials.
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Lütgebaucks C, Macias-Romero C, Roke S. Characterization of the interface of binary mixed DOPC:DOPS liposomes in water: The impact of charge condensation. J Chem Phys 2018; 146:044701. [PMID: 28147550 DOI: 10.1063/1.4974084] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Solutions of liposomes composed of binary mixtures of anionic dioleoylphosphatidylserine (DOPS) and zwitterionic dioleoylphosphatidylcholine (DOPC) are investigated with label-free angle-resolved (AR) second harmonic scattering (SHS) and electrophoretic mobility measurements. The membrane surface potential is extracted from the AR-SHS response. The surface potential changes from -10 to -145 mV with varying DOPS content ( from 0% to 100%) and levels off already at ∼ 10 % DOPS content. The ζ-potential shows the same trend but with a drastically lower saturation value (-44 mV). This difference is explained by the formation of a condensed layer of Na+ counterions around the outer leaflet of the liposome as predicted by charge condensation theories for polyelectrolyte systems.
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Affiliation(s)
- Cornelis Lütgebaucks
- Laboratory for fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Carlos Macias-Romero
- Laboratory for fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sylvie Roke
- Laboratory for fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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30
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Sharifian Gh. M, Wilhelm MJ, Dai HL. Azithromycin-Induced Changes to Bacterial Membrane Properties Monitored in Vitro by Second-Harmonic Light Scattering. ACS Med Chem Lett 2018; 9:569-574. [PMID: 29937984 DOI: 10.1021/acsmedchemlett.7b00499] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 03/09/2018] [Indexed: 01/15/2023] Open
Abstract
We present a nonlinear light scattering method for monitoring, with real-time resolution and membrane specificity, changes in molecular adsorption, and transport at bacterial membranes induced by an antimicrobial compound. Specifically, time-resolved second-harmonic light scattering (SHS) is used to quantify azithromycin-induced changes to bacterial membrane permeability in colloidal suspensions of living Escherichia coli. Variations in membrane properties are monitored through changes in the adsorption and transport rates of malachite green, a hydrophobic cation that gives SHS signal. Regardless of concentration, instantaneous treatment with azithromycin showed no significant changes in membrane permeability. However, 1 h pretreatment with subminimum inhibitory concentrations of azithromycin induced an order-of-magnitude enhancement in the permeability of both the outer membrane and, through facilitation of a new transport mechanism, the cytoplasmic membrane of the bacteria as well. This study illustrates SHS as a novel tool for monitoring antimicrobial-induced changes to membrane properties in living bacteria.
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Affiliation(s)
- Mohammad Sharifian Gh.
- Department of Chemistry, Temple University
, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States
| | - Michael J. Wilhelm
- Department of Chemistry, Temple University
, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States
| | - Hai-Lung Dai
- Department of Chemistry, Temple University
, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States
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31
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Makarem M, Lee CM, Sawada D, O'Neill HM, Kim SH. Distinguishing Surface versus Bulk Hydroxyl Groups of Cellulose Nanocrystals Using Vibrational Sum Frequency Generation Spectroscopy. J Phys Chem Lett 2018; 9:70-75. [PMID: 29232139 DOI: 10.1021/acs.jpclett.7b02729] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In plant cell walls and cellulose-containing composites, nanocrystalline cellulose interacts with water molecules or matrix polymers through hydrogen bonding of the hydroxyl groups at the cellulose surface. These interactions play key roles in cellulose assembly in plant cell walls and mechanical properties of cellulose composites; however, they could not be studied properly due to the spectroscopic difficulty of selectively detecting the surface hydroxyl groups of nanocrystalline domains. This study employed the sum frequency scattering principle to distinguish the hydroxyl groups inside of the crystalline nanodomain of cellulose and those exposed at the surface of crystalline domains. The comparison of the spectra at various scattering angles revealed that the OH peak near ∼3450 cm-1 comes from the weakly hydrogen-bonded OH groups at the surface of crystalline cellulose. Also, a time delay measurement found that the sharp vibrational features observed near 3700 cm-1 can be attributed to isolated OH groups not accessible by ambient water molecules. These findings allow the distinction of surface versus bulk OH groups in sum frequency generation vibrational spectroscopy.
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Affiliation(s)
- Mohamadamin Makarem
- Department of Chemical Engineering, Materials Research Insitute, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Christopher M Lee
- Department of Chemical Engineering, Materials Research Insitute, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Daisuke Sawada
- Biology and Soft Matter Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Hugh M O'Neill
- Biology and Soft Matter Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Seong H Kim
- Department of Chemical Engineering, Materials Research Insitute, Pennsylvania State University , University Park, Pennsylvania 16802, United States
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32
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Zdrali E, Chen Y, Okur HI, Wilkins DM, Roke S. The Molecular Mechanism of Nanodroplet Stability. ACS NANO 2017; 11:12111-12120. [PMID: 29224343 DOI: 10.1021/acsnano.7b05100] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Mixtures of nano- and microscopic oil droplets in water have recently been rediscovered as miniature reaction vessels in microfluidic environments and are important constituents of many environmental systems, food, personal care, and medical products. The oil nanodroplet/water interface stabilized by surfactants determines the physicochemical properties of the droplets. Surfactants are thought to stabilize nanodroplets by forming densely packed monolayers that shield the oil phase from the water. This idea has been inferred from droplet stability measurements in combination with molecular structural data obtained from extended planar interfaces. Here, we present a molecular level investigation of the surface structure and stability of nanodroplets and show that the surface structure of nanodroplets is significantly different from that of extended planar interfaces. Charged surfactants form monolayers that are more than 1 order of magnitude more dilute than geometrically packed ones, and there is no experimental correlation between stability and surfactant surface density. Moreover, dilute negatively charged surfactant monolayers produce more stable nanodroplets than dilute positively charged and dense geometrically packed neutral surfactant monolayers. Droplet stability is found to depend on the relative cooperativity between charge-charge, charge-dipole, and hydrogen-bonding interactions. The difference between extended planar interfaces and nanoscale interfaces stems from a difference in the thermally averaged total charge-charge interactions in the two systems. Low dielectric oil droplets with a size smaller than the Debye length in oil permit repulsive interactions between like charges from opposing interfaces in small droplets. This behavior is generic and extends up to the micrometer length scale.
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Affiliation(s)
- Evangelia Zdrali
- Laboratory for Fundamental BioPhotonics, Institutes of Bioengineering and Materials Science and Engineering, School of Engineering, and Lausanne Centre for Ultrafast Science, École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland
| | - Yixing Chen
- Laboratory for Fundamental BioPhotonics, Institutes of Bioengineering and Materials Science and Engineering, School of Engineering, and Lausanne Centre for Ultrafast Science, École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland
| | - Halil I Okur
- Laboratory for Fundamental BioPhotonics, Institutes of Bioengineering and Materials Science and Engineering, School of Engineering, and Lausanne Centre for Ultrafast Science, École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland
| | - David M Wilkins
- Laboratory of Computational Science and Modeling, Institute of Materials, École Polytechnique Fédérale de Lausanne , 1015 Lausanne, Switzerland
| | - Sylvie Roke
- Laboratory for Fundamental BioPhotonics, Institutes of Bioengineering and Materials Science and Engineering, School of Engineering, and Lausanne Centre for Ultrafast Science, École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland
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33
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Smit WJ, Smolentsev N, Versluis J, Roke S, Bakker HJ. Freezing effects of oil-in-water emulsions studied by sum-frequency scattering spectroscopy. J Chem Phys 2016; 145:044706. [DOI: 10.1063/1.4959128] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- W. J. Smit
- FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - N. Smolentsev
- Laboratory for Fundamental Biophotonics (LBP), Institute of Bioengineering (IBI), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - J. Versluis
- FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - S. Roke
- Laboratory for Fundamental Biophotonics (LBP), Institute of Bioengineering (IBI), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - H. J. Bakker
- FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
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34
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de Beer AGF, Roke S. What interactions can distort the orientational distribution of interfacial water molecules as probed by second harmonic and sum frequency generation? J Chem Phys 2016; 145:044705. [DOI: 10.1063/1.4959033] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Alex G. F. de Beer
- Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), Institute of Materials Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sylvie Roke
- Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), Institute of Materials Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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35
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Chen Y, Okur HI, Gomopoulos N, Macias-Romero C, Cremer PS, Petersen PB, Tocci G, Wilkins DM, Liang C, Ceriotti M, Roke S. Electrolytes induce long-range orientational order and free energy changes in the H-bond network of bulk water. SCIENCE ADVANCES 2016; 2:e1501891. [PMID: 27152357 PMCID: PMC4846452 DOI: 10.1126/sciadv.1501891] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 03/06/2016] [Indexed: 05/05/2023]
Abstract
Electrolytes interact with water in many ways: changing dipole orientation, inducing charge transfer, and distorting the hydrogen-bond network in the bulk and at interfaces. Numerous experiments and computations have detected short-range perturbations that extend up to three hydration shells around individual ions. We report a multiscale investigation of the bulk and surface of aqueous electrolyte solutions that extends from the atomic scale (using atomistic modeling) to nanoscopic length scales (using bulk and interfacial femtosecond second harmonic measurements) to the macroscopic scale (using surface tension experiments). Electrolytes induce orientational order at concentrations starting at 10 μM that causes nonspecific changes in the surface tension of dilute electrolyte solutions. Aside from ion-dipole interactions, collective hydrogen-bond interactions are crucial and explain the observed difference of a factor of 6 between light water and heavy water.
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Affiliation(s)
- Yixing Chen
- Laboratory for fundamental BioPhotonics, Institutes of Bioengineering and Materials Science and Engineering, School of Engineering, and Lausanne Centre for Ultrafast Science, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Halil I. Okur
- Department of Chemistry, Pennsylvania State University, University Park, PA 16802, USA
| | - Nikolaos Gomopoulos
- Laboratory for fundamental BioPhotonics, Institutes of Bioengineering and Materials Science and Engineering, School of Engineering, and Lausanne Centre for Ultrafast Science, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Carlos Macias-Romero
- Laboratory for fundamental BioPhotonics, Institutes of Bioengineering and Materials Science and Engineering, School of Engineering, and Lausanne Centre for Ultrafast Science, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Paul S. Cremer
- Department of Chemistry, Pennsylvania State University, University Park, PA 16802, USA
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Poul B. Petersen
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Gabriele Tocci
- Laboratory for fundamental BioPhotonics, Institutes of Bioengineering and Materials Science and Engineering, School of Engineering, and Lausanne Centre for Ultrafast Science, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Laboratory of Computational Science and Modeling, Institute of Materials Science and Engineering, School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - David M. Wilkins
- Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK
| | - Chungwen Liang
- Laboratory of Computational Science and Modeling, Institute of Materials Science and Engineering, School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Michele Ceriotti
- Laboratory of Computational Science and Modeling, Institute of Materials Science and Engineering, School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sylvie Roke
- Laboratory for fundamental BioPhotonics, Institutes of Bioengineering and Materials Science and Engineering, School of Engineering, and Lausanne Centre for Ultrafast Science, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Corresponding author. E-mail:
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36
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Smolentsev N, Lütgebaucks C, Okur HI, de Beer AGF, Roke S. Intermolecular Headgroup Interaction and Hydration as Driving Forces for Lipid Transmembrane Asymmetry. J Am Chem Soc 2016; 138:4053-60. [DOI: 10.1021/jacs.5b11776] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Nikolay Smolentsev
- Laboratory for Fundamental
BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute
of Materials Science (IMX), School of Engineering (STI), and Lausanne
Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Cornelis Lütgebaucks
- Laboratory for Fundamental
BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute
of Materials Science (IMX), School of Engineering (STI), and Lausanne
Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Halil I. Okur
- Laboratory for Fundamental
BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute
of Materials Science (IMX), School of Engineering (STI), and Lausanne
Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Alex G. F. de Beer
- Laboratory for Fundamental
BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute
of Materials Science (IMX), School of Engineering (STI), and Lausanne
Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sylvie Roke
- Laboratory for Fundamental
BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute
of Materials Science (IMX), School of Engineering (STI), and Lausanne
Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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37
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Chen Y, Jena KC, Lütgebaucks C, Okur HI, Roke S. Three Dimensional Nano "Langmuir Trough" for Lipid Studies. NANO LETTERS 2015; 15:5558-5563. [PMID: 26151602 DOI: 10.1021/acs.nanolett.5b02143] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A three-dimensional-phospholipid monolayer with tunable molecular structure was created on the surface of oil nanodroplets from a mixture of phospholipids, oil, and water. This simple nanoemulsion preparation technique generates an in situ prepared membrane model system with controllable molecular surface properties that resembles a lipid droplet. The molecular interfacial structure of such a nanoscopic system composed of hexadecane, 1,2-dihexadecanoyl-sn-glycero-3-phosphocholine (DPPC), and water was determined using vibrational sum frequency scattering and second harmonic scattering techniques. The droplet surface structure of DPPC can be tuned from a tightly packed liquid condensed phase like monolayer to a more dilute one that resembles the liquid condensed/liquid expanded coexistence phase by varying the DPPC/oil/water ratio. The tunability of the chemical structure, the high surface-to-volume ratio, and the small sample volume make this system an ideal model membrane for biochemical research.
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Affiliation(s)
- Yixing Chen
- †Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Kailash C Jena
- †Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
- ‡Department of Physics, Indian Institute of Technology Ropar, Rupnagar, 140001, India
| | - Cornelis Lütgebaucks
- †Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Halil I Okur
- †Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Sylvie Roke
- †Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
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38
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Samson JS, Scheu R, Smolentsev N, Rick SW, Roke S. Sum frequency spectroscopy of the hydrophobic nanodroplet/water interface: Absence of hydroxyl ion and dangling OH bond signatures. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2014.09.034] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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39
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Johansson P, Koelsch P. Vibrational sum-frequency scattering for detailed studies of collagen fibers in aqueous environments. J Am Chem Soc 2014; 136:13598-601. [PMID: 25225785 PMCID: PMC4183644 DOI: 10.1021/ja508190d] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Indexed: 12/17/2022]
Abstract
Protein fibers play a crucial role in many disease related phenomena and biological systems. A structural analysis of fibrous proteins often requires labeling approaches or disruptive sample preparation while it lacks chemical specificity. Here we demonstrate that the technique of vibrational sum-frequency scattering (SFS) provides a label-free pathway for the chemical and structural analysis of protein fibers in solution. By examining collagen, the most abundant protein in mammals, we demonstrate that the SFS signal of fibers can be detected in the NH, CH stretching and bending, and amide I regions. SFS spectra were found to depend on the scattering angle, which implies the possibility to selectively probe various features of the fibers. The fitting of the data and maximum entropy method analysis revealed a different phase for side-chains and carbonyl contributions, which helps to identify these otherwise overlapping spectral peaks and provides the possibility to perform orientational analysis. Our findings suggest that SFS allows for the greater understanding of protein fibers in solution, which is important when, for example, designing scaffolds in tissue engineering or developing cures for diseases associated with protein fibers.
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Affiliation(s)
- Patrik
K. Johansson
- National
ESCA and Surface
Analysis Center for Biomedical Problems, Department of Bioengineering, University of Washington, Seattle, Washington 98195, United States
| | - Patrick Koelsch
- National
ESCA and Surface
Analysis Center for Biomedical Problems, Department of Bioengineering, University of Washington, Seattle, Washington 98195, United States
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40
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Scheu R, Rankin BM, Chen Y, Jena KC, Ben-Amotz D, Roke S. Charge Asymmetry at Aqueous Hydrophobic Interfaces and Hydration Shells. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201310266] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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41
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Scheu R, Rankin BM, Chen Y, Jena KC, Ben-Amotz D, Roke S. Charge asymmetry at aqueous hydrophobic interfaces and hydration shells. Angew Chem Int Ed Engl 2014; 53:9560-3. [PMID: 25045022 DOI: 10.1002/anie.201310266] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Guilty as charged: Water is often modeled as a dielectric continuum, but the molecular structure of water is asymmetric. Two ions that have a virtually identical size, shape, and structure, but an opposite charge sign have been investigated to see whether charge makes a fundamental difference to water structuring. The spectroscopic data for the hydration and interface structures are found to be remarkably different for opposite charges.
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Affiliation(s)
- Rüdiger Scheu
- Laboratory for fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), School of Engineering (STI), École Polytechnique Féderale de Lausanne (EPFL), 1015 Lausanne (Switzerland)
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42
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Scheu R, Roke S. Toward Vibrational Dynamics at Liquid–Liquid and Nano-Interfaces: Time-Resolved Sum-Frequency Scattering. J Phys Chem B 2014; 118:3366-71. [DOI: 10.1021/jp411798s] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Rüdiger Scheu
- Laboratory of fundamental
BioPhotonics (LBP), Institute of Bioengineering (IBI), School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Sylvie Roke
- Laboratory of fundamental
BioPhotonics (LBP), Institute of Bioengineering (IBI), School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
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43
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Scheu R, Chen Y, de Aguiar HB, Rankin BM, Ben-Amotz D, Roke S. Specific Ion Effects in Amphiphile Hydration and Interface Stabilization. J Am Chem Soc 2014; 136:2040-7. [DOI: 10.1021/ja4120117] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rüdiger Scheu
- Laboratory
for Fundamental BioPhotonics (LBP), Institute of Bio-Engineering (IBI),
School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), Station 17, CH-1015 Lausanne, Switzerland
| | - Yixing Chen
- Laboratory
for Fundamental BioPhotonics (LBP), Institute of Bio-Engineering (IBI),
School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), Station 17, CH-1015 Lausanne, Switzerland
| | - Hilton B. de Aguiar
- Laboratory
for Fundamental BioPhotonics (LBP), Institute of Bio-Engineering (IBI),
School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), Station 17, CH-1015 Lausanne, Switzerland
| | - Blake M. Rankin
- Department
of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Dor Ben-Amotz
- Department
of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Sylvie Roke
- Laboratory
for Fundamental BioPhotonics (LBP), Institute of Bio-Engineering (IBI),
School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), Station 17, CH-1015 Lausanne, Switzerland
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44
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Scheu R, Chen Y, Subinya M, Roke S. Stern Layer Formation Induced by Hydrophobic Interactions: A Molecular Level Study. J Am Chem Soc 2013; 135:19330-5. [DOI: 10.1021/ja4102858] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Rüdiger Scheu
- Laboratory for fundamental BioPhotonics (LBP), Institute
of Bioengineering (IBI), School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Yixing Chen
- Laboratory for fundamental BioPhotonics (LBP), Institute
of Bioengineering (IBI), School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Mireia Subinya
- Institute of Physical Chemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | - Sylvie Roke
- Laboratory for fundamental BioPhotonics (LBP), Institute
of Bioengineering (IBI), School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
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45
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Wunderlich S, Peschel U. Plasmonic enhancement of second harmonic generation on metal coated nanoparticles. OPTICS EXPRESS 2013; 21:18611-18623. [PMID: 23938778 DOI: 10.1364/oe.21.018611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Second Harmonic Generation (SHG) is a widely used tool to study surfaces. Here we investigate SHG from spherical nanoparticles consisting of a dielectric core (radius 100 nm) and a metallic shell of variable thickness. Plasmonic resonances occur that depend on the thickness of the nanoshells and boost the intensity of the Second Harmonic (SH) signal. The origin of the resonances is studied for the fundamental harmonic and the second harmonic frequencies. Mie resonances at the fundamental harmonic frequency dominate resonant effects of the SH-signal at low shell thickness. Resonances excited by a dipole emitting at SH frequency close to the surface explain the enhancement of the SHG-process at a larger shell thickness. All resonances are caused by surface plasmon polaritons, which run on the surface of the spherical particle and are in resonance with the circumference of the sphere. Because their wavelength critically depends on the properties of the metallic layer SHG resonances of core-shell nanoparticles can be easily tuned by varying the thickness of the shell.
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Affiliation(s)
- Sarina Wunderlich
- Institute of Optics, Information and Photonics, University of Erlangen-Nuremberg, Germany
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Vácha R, Roke S. Sodium Dodecyl Sulfate at Water–Hydrophobic Interfaces: A Simulation Study. J Phys Chem B 2012; 116:11936-42. [DOI: 10.1021/jp304900z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Robert Vácha
- National Centre for Biomolecular
Research, Faculty of Science and CEITEC—Central European Institute
of Technology, Masaryk University, Kamenice
5, 625 00 Brno-Bohunice, Czech Republic
| | - Sylvie Roke
- Laboratory for Fundamental BioPhotonics
(LBP), Institute of Bioengineering (IBI), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
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Roke S, Gonella G. Nonlinear Light Scattering and Spectroscopy of Particles and Droplets in Liquids. Annu Rev Phys Chem 2012; 63:353-78. [DOI: 10.1146/annurev-physchem-032511-143748] [Citation(s) in RCA: 185] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Sylvie Roke
- Laboratory for fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland;
- Max-Planck Institute for Metals Research, 70569 Stuttgart, Germany
| | - Grazia Gonella
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122;
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de Aguiar HB, Scheu R, Jena KC, de Beer AGF, Roke S. Comparison of scattering and reflection SFG: a question of phase-matching. Phys Chem Chem Phys 2012; 14:6826-32. [DOI: 10.1039/c2cp40324b] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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49
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de Beer AGF, Samson JS, Hua W, Huang Z, Chen X, Allen HC, Roke S. Direct comparison of phase-sensitive vibrational sum frequency generation with maximum entropy method: Case study of water. J Chem Phys 2011; 135:224701. [DOI: 10.1063/1.3662469] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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50
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Probing nanoscopic droplet interfaces in aqueous solution with vibrational sum-frequency scattering: A study of the effects of path length, droplet density and pulse energy. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2011.06.081] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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