Bulk Contributions Modulate the Sum-Frequency Generation Spectra of Interfacial Water on Model Sea-Spray Aerosols

Reddy, Sandeep K.; Thiraux, Raphael; Rudd, Bethany A. Wellen; Lu, Lin; Adel, Tehseen; Joutsuka, Tatsuya; Geiger, Franz M.; Allen, Heather C.; Morita, Akihiro; Paesani, Francesco

doi:10.26434/chemrxiv.5743638.v1

Cited by 6 publications

(7 citation statements)

References 74 publications

(108 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Rather than being due to changes in the H-bonding network, we find that the SFG signal intensity reductions that coincide with raising the salt concentration from 10 µM to 0.1 M are consistent with absorptive-dispersive mixing between χ (2) and χ (3) contributions to the SFG signal generation process from charged interfaces, according to [64][65][66][67][68][69][70]…”

Section: Resultssupporting

confidence: 53%

Hydrogen Bond Networks Near Supported Lipid Bilayers from Vibrational Sum Frequency Generation Experiments and Atomistic Simulations

Doğangün¹,

Ohno²,

Liang³

et al. 2018

Preprint

View full text Add to dashboard Cite

<div> <div> <p>We report vibrational sum frequency generation (SFG) spectra in which the C–H stretches of lipid alkyl tails in fully hydrogenated single- and dual-component supported lipid bilayers are detected along with the O–H stretching continuum above the bilayer. As the salt concentration is increased from ~10 μM to 0.1 M, the SFG intensities in the O–H stretching region decrease by a factor of 2, consistent with significant absorptive-dispersive mixing between χ(2) and χ(3) contributions to the SFG signal generation process from charged interfaces. A method for estimating the surface potential from the second-order spectral lineshapes (in the OH stretching region) is presented and discussed in the context of choosing truly zero-potential reference states. Aided by atomistic simulations, we find that the strength and orientation distribution of the hydrogen bonds over the purely zwitterionic bilayers are largely invariant between sub-micromolar and hundreds of millimolar concentrations. However, specific interactions between water molecules and lipid headgroups are observed upon replacing phosphocholine (PC) lipids with negatively charged phosphoglycerol (PG) lipids, which coincides with SFG signal intensity reductions in the 3100 cm-1 to 3200 cm-1 frequency region. The atomistic simulations show that this outcome is consistent with a small, albeit statistically significant, decrease in the number of water molecules adjacent to both the lipid phosphate and choline moieties per unit area, supporting the SFG observations. Ultimately, the ability to probe hydrogen-bond networks over lipid bilayers holds the promise of opening paths for understanding, controlling, and predicting specific and non-specific interactions between membranes and ions, small molecules, peptides, polycations, proteins, and coated and uncoated nanomaterials.<br></p></div></div>

show abstract

Section: Resultssupporting

confidence: 53%

Hydrogen Bond Networks Near Supported Lipid Bilayers from Vibrational Sum Frequency Generation Experiments and Atomistic Simulations

Doğangün¹,

Ohno²,

Liang³

et al. 2018

Preprint

View full text Add to dashboard Cite

show abstract

“…Rather than being due to changes in the H-bonding network, we find that the SFG signal intensity reductions that coincide with raising the salt concentration from 10 μM to 0.1 M are consistent with absorptive–dispersive mixing between χ (2) and χ (3) contributions to the SFG signal generation process from charged interfaces, according to − Here, the first two terms are the nonresonant and resonant second-order susceptibility and the third term is given by the inverse Debye screening length, κ, the inverse of the coherence length of the SFG process, Δ k z , and the interfacial potential, Φ(0), multiplied by the third-order susceptibility. ,, We recently showed − that, for an exponential distance dependence of Φ( z ), the χ (3) phase angle, φ, equals arctan(Δ k z /κ). Using “primitive ion” models, such as Gouy–Chapman theory, we estimate at the low (resp.…”

Section: Resultsmentioning

confidence: 69%

Hydrogen-Bond Networks near Supported Lipid Bilayers from Vibrational Sum Frequency Generation Experiments and Atomistic Simulations

et al. 2018

Self Cite

View full text Add to dashboard Cite

We report vibrational sum frequency generation (SFG) spectra in which the C-H stretches of lipid alkyl tails in fully hydrogenated single- and dual-component supported lipid bilayers are detected along with the O-H stretching continuum above the bilayer. As the salt concentration is increased from ∼10 μM to 0.1 M, the SFG intensities in the O-H stretching region decrease by a factor of 2, consistent with significant absorptive-dispersive mixing between χ and χ contributions to the SFG signal generation process from charged interfaces. A method for estimating the surface potential from the second-order spectral lineshapes (in the OH stretching region) is presented and discussed in the context of choosing truly zero-potential reference states. Aided by atomistic simulations, we find that the strength and orientation distribution of the hydrogen bonds over the purely zwitterionic bilayers are largely invariant between submicromolar and hundreds of millimolar concentrations. However, specific interactions between water molecules and lipid headgroups are observed upon replacing phosphocholine (PC) lipids with negatively charged phosphoglycerol (PG) lipids, which coincides with SFG signal intensity reductions in the 3100-3200 cm frequency region. The atomistic simulations show that this outcome is consistent with a small, albeit statistically significant, decrease in the number of water molecules adjacent to both the lipid phosphate and choline moieties per unit area, supporting the SFG observations. Ultimately, the ability to probe hydrogen-bond networks over lipid bilayers holds the promise of opening paths for understanding, controlling, and predicting specific and nonspecific interactions between membranes and ions, small molecules, peptides, polycations, proteins, and coated and uncoated nanomaterials.

show abstract

“…spectroscopy provides an indirect measure of ion adsorption, through the changes happening to the interfacial water structure or the surface functional groups. [26][27]33 Recently, Sthoer et al reported an observation of overcharging of Y 3+ and La 3+ ions at arachidic acid (AA) monolayers with SFG spectroscopy. 27 The intensity of -OH region signal (3200 -3700 cm -1 ) decreased as the bulk concentration is increased from 100 nM to 10 M, which is typical due to the decreasing surface charge and disturbed interfacial water organization.…”

mentioning

confidence: 99%

Elucidating Trivalent Ion Adsorption at Floating Carboxylic Acid Monolayers: Charge Reversal or Water Reorganization?

Nayak

Kumal

Lee

et al. 2023

Preprint

View full text Add to dashboard Cite

We study trivalent neodymium adsorption on floating arachidic acid films at the air/water interface by two complementary surface specific probes, sum frequency generation (SFG) spectroscopy and X-ray fluorescence near total reflection (XFNTR). In the absence of background ions, neodymium ions compensate the surface charge of the arachidic acid film at 50 M bulk concentration without any charge reversal. Increasing the bulk concentration to 1 mM does not change the neodymium surface coverage but affects the interfacial water structure significantly. In the presence of a high concentration of background salt, NaCl, there is overcharging at 1mM of Nd3+ i.e., 30% more Nd3+ than needed to compensate the surface charge. The overcharging trend with and without salts is different than those observed at mineral/water interface, emphasizing the importance of surface properties. These results show that the total coverage of neodymium ions is not enough to describe the complete picture at the interface, and interfacial water and ion coverage needs to be considered together to understand more complex ion adsorption and transport processes.

show abstract

Bulk Contributions Modulate the Sum-Frequency Generation Spectra of Interfacial Water on Model Sea-Spray Aerosols

Cited by 6 publications

References 74 publications

Hydrogen Bond Networks Near Supported Lipid Bilayers from Vibrational Sum Frequency Generation Experiments and Atomistic Simulations

Hydrogen Bond Networks Near Supported Lipid Bilayers from Vibrational Sum Frequency Generation Experiments and Atomistic Simulations

Hydrogen-Bond Networks near Supported Lipid Bilayers from Vibrational Sum Frequency Generation Experiments and Atomistic Simulations

Elucidating Trivalent Ion Adsorption at Floating Carboxylic Acid Monolayers: Charge Reversal or Water Reorganization?

Contact Info

Product

Resources

About