Charge Inversion at the Surface by Adsorption of Trivalent Cations on Langmuir Monolayer

Seok, Sangjun; Kim, Doseok

doi:10.1109/cleopr.2007.4391639

Cited by 3 publications

(2 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such interface overcharging induced by trivalent metal ions has already been reported for phospholipid monolayers. 55,56 For that, we now discuss the changes in the shape of the 3060 cm -1 band due to aromatic C-H stretching vibrations (shaded areas in Figure 2). For both salts this bands appears as highly dispersive feature with a dip in SFG intensity close to 3060 cm -1 , at low ion concentrations.…”

Section: Interfacial Behavior Of Blg As a Function Of Nd 3+ And Y 3+ mentioning

confidence: 99%

Specific Ion Effects of Trivalent Cations on the Structure and Charging State of β-Lactoglobulin Adsorption Layers

2019

View full text Add to dashboard Cite

Properties of proteins at interfaces are important to a many processes as well as in soft matter materials such as aqueous foam. Particularly, the protein interfacial behavior is strongly linked to different factors like the solution pH or the presence of electrolytes. Here the nature of the electrolyte ions can significantly modify the interfacial properties of proteins. Therefore, molecular level studies on interfacial structures and charging states are needed. In this work, we addressed the effects of Y 3+ and Nd 3+ cations on the adsorption of the whey protein β-lactoglobulin (BLG) at airwater interfaces as a function of electrolyte concentration. Both cations caused very similar but dramatic changes at the interface and in the bulk solution. Here, measurements of the electrophoretic mobility and vibrational sum-frequency generation spectroscopy (SFG) were applied and consistently showed a reversal of the BLG net charge at remarkably low ion concentrations of 30

show abstract

Section: Interfacial Behavior Of Blg As a Function Of Nd 3+ And Y 3+ mentioning

confidence: 99%

Specific Ion Effects of Trivalent Cations on the Structure and Charging State of β-Lactoglobulin Adsorption Layers

2019

View full text Add to dashboard Cite

show abstract

“…Infrared-visible sum-frequency vibrational spectroscopy (SFS) is a surface-sensitive second-order nonlinear optical technique which offers submonolayer sensitivity and the possibility to characterize the ordering, orientation, and conformation of molecular species in the interfacial region. , Several research groups employed sum-frequency spectroscopy to study the structures and properties of lipid monolayers at the liquid/air interface − and of supported lipid bilayers − as well as for the molecular level characterization of the interactions of lipid monolayers − and bilayers − with peptides. The effect of various other substancessimple ions, − surfactants, , polysaccharides, − even DNA , on the structure and organization of phospholipid monolayers at the liquid/air interface was also investigated by sum-frequency spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

Interaction of Phospholipid Langmuir Monolayers with an Antibiotic Peptide Conjugate

2013

View full text Add to dashboard Cite

The interactions between phospholipid monolayers and a peptide conjugate of the antituberculotic agent isoniazide (INH) were investigated by sum-frequency vibrational spectroscopy. The primary objective of the present work was to provide a detailed picture of the molecular interactions of the INH-peptide conjugate with phospholipid monolayers by detecting the changes in the monolayer structure resulting from these interactions. In order to gain a thorough understanding, three types of experiment were performed: (i) changes induced in the structure of the precompressed phospholipid monolayer upon injection of the INH-peptide conjugate were followed; (ii) the structures of the phospholipid monolayers spread onto the solution of the INH-peptide conjugate were characterized; (iii) the structures of mixed monolayers of phospholipid and the INH-peptide conjugate were studied. Using a chain perdeuterated phospholipid, it was possible to examine the changes in alkyl chain ordering without interference from INH-peptide conjugate vibrations and investigate the effect of the INH-peptide conjugate on the ordering of the phosphocholine headgroups. We confirmed that peptide conjugation strongly influences the interactions of INH with the lipid monolayer, resulting in enhanced cell penetration ability. The interactions formed between the INH-peptide conjugate in its ordered adsorption layer and the phospholipid molecules deposited onto this solution were found to be significantly stronger than those formed by the INH-peptide conjugate with a compressed lipid monolayer. Nonetheless, both types of interaction contribute with a condensing effect to an increased ordering of the phospholipid alkyl chains in the monolayer.

show abstract

Estudo da inversão de carga em filmes de Langmuir

Botelho¹

View full text Add to dashboard Cite

DedicatóriaDedico esse e todos os meus outros trabalhos, passados e futuros, aos meus pais. AgradecimentosAo Prof. Paulo por me orientar. Pela paixão contagiante pelo que faz, e paciência e compreensão inesgotáveis.Ao pessoal do laboratório (Marcela, Shikão, Heurison, Marcelo e Thiers) pela ajuda, companheirismo e momentos memoráveis vividos dentro daquele lugar gélido.A todo mundo que compõe o grupo de polímeros, em especial aos técnicos: Níbio, Bertho, Ademir e Débora e a nossa secretária, Ro.Ao pessoal da sala (Mike, Nirton, Ângelo e Kleber) pelas conversas e pela divertida convivência diária.Aos amigos que fiz durante esse período e que vou levar para toda vida: Re, Van e o Caboclo.Aos meus bixinhos (Clara e Camis) que não importa onde estejam sempre terão um papel fundamental na minha vida.A todos os meus amigos que sempre me deram suporte. Cito aqui Chris, Daniel, Bodocó e Eglânio como representantes destes.Aos meus pais, Cristina e Samuel, e a minha irmã, Maíra, que serão sempre o meu porto seguro. Não importa a situação eu sei que neles eu sempre encontrarei conforto.À tia Penha e a Maria que são segundas mães para mim.Ao meu Bol por existir e me amar.À FAPESP pelo fomento necessário para o desenvolvimento deste trabalho. The study of charged interfaces is important for understanding several phenomena in polymer and colloid science, as well as in molecular biology. Even though this topic has benn extensively investigated, there are many open issues, such as details of ion-ion interactions. In this context, this work investigates charge inversion in Langmuir films of DMPA (dimyristoilphosphatidic acid -an anionic phospholipid) spread on aqueous solutions of LaCl 3 . Similar effects have been previously observed for DMPA films on subphases containing BaCl 2 and CsI, but charge inversion for DMPA monolayers spread on LaCl 3 solutions has been recently reported for Lanthanum Chloride concentrations that are four orders of magnitude lower than predicted by ion-ion correlation theories. We have performed surface tension, surface potential, sum-frequency generation (SFG) spectroscopy and Brewster angle microscopy experiments, as well as calculations of monolayer ionization, with the goal of confirming charge inversion and providing additional structural information for this system. It was observed that the addition of trivalent ions in the subphase induced the formation of domains in the DMPA monolayers, sparking our interest in obtaining images by SFG microscopy of these films. Therefore, besides the study of DMPA Langmuir films on subphases containing LaCl 3 , we have also designed an SFG microscope.Keywords: SFG spectroscopy. Langmuir films. Charge inversion. SFG microscopy. Lista de FigurasFigura 1 -Principal resultado do experimento de espalhamento de raio-X realizado por J.Pittler et al. (1) Origens do Sinal SFGQuando uma onda luminosa se propaga em um meio material, seu campo elétrico exerce uma força sobre os elétrons das moléculas que constituem o meio. Nos casos em que essa radiação não é coerente e ...

show abstract

Charge Inversion at the Surface by Adsorption of Trivalent Cations on Langmuir Monolayer

Cited by 3 publications

References 3 publications

Specific Ion Effects of Trivalent Cations on the Structure and Charging State of β-Lactoglobulin Adsorption Layers

Specific Ion Effects of Trivalent Cations on the Structure and Charging State of β-Lactoglobulin Adsorption Layers

Interaction of Phospholipid Langmuir Monolayers with an Antibiotic Peptide Conjugate

Estudo da inversão de carga em filmes de Langmuir

Contact Info

Product

Resources

About