Unique fluorescence spectra of a disubstituted pyrene surfactant in Langmuir–Blodgett films

Sakomura, Masaru; Nakashima, Tomonori; Ueda, Kazuyoshi; Fujihira, Masamichi

doi:10.1016/j.colsurfa.2005.11.083

Cited by 9 publications

(5 citation statements)

References 14 publications

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“…Our observations confirm that the presence of pyrene as a hydrophobic moiety in an amphiphile not only enriches its aggregation and interfacial behaviour, but also provides a range of additional probing techniques via the well characterised pyrene fluorescence. Similar investigations have been undertaken recently for pyrene‐labelled lipids,16 pyrene‐labelled Gemini surfactants17 or other pyrene‐labelled compounds of biophysical interest 18. As in our case, many open questions remain, in particular concerning the organisation of the molecules in the bulk or at interfaces for the entire accessible concentration range, which will have to be addressed in the future.…”

Section: Discussionsupporting

confidence: 63%

Ca2+ homeostasis defects and hereditary hearing loss

Mammano

2011

BioFactors

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Ca(2+) acts as a fundamental signal transduction element in inner ear, delivering information about sound, acceleration and gravity through a small number of mechanotransduction channels in the hair cell stereocilia and voltage activated Ca(2+) channels at the ribbon synapse, where it drives neurotransmission. The mechanotransduction process relies on the endocochlear potential, an electrical potential difference between endolymph and perilymph, the two fluids bathing respectively the apical and basolateral membrane of the cells in the organ of Corti. In mouse models, deafness and lack or reduction of the endocochlear potential correlate with ablation of connexin (Cx) 26 or 30. These Cxs form heteromeric channels assembled in a network of gap junction plaques connecting the supporting and epithelial cells of the organ of Corti presumably for K(+) recycle and transfer of key metabolites, for example, the Ca(2+) -mobilizing second messenger IP(3) . Ca(2+) signaling in these cells could play a crucial role in regulating Cx expression and function. Another district where Ca(2+) signaling alterations link to hearing loss is hair cell apex, where ablation or missense mutations of the PMCA2 Ca(2+) -pump of the stereocilia cause deafness and loss of balance. If less Ca(2+) is exported from the stereocilia, as in the PMCA2 mouse mutants, Ca(2+) concentration in endolymph is expected to fall causing an alteration of the mechanotransduction process. This may provide a clue as to why, in some cases, PMCA2 mutations potentiated the deafness phenotype induced by coexisting mutations of cadherin-23 (Usher syndrome type 1D), a single pass membrane Ca(2+) binding protein that is abundantly expressed in the stereocilia.

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Section: Discussionsupporting

confidence: 63%

Ca2+ homeostasis defects and hereditary hearing loss

Mammano

2011

BioFactors

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“…Similar investigations have been undertaken recently for pyrene-labelled lipids, [16] pyrene-labelled Gemini surfactants [17] or other pyrene-labelled compounds of biophysical interest. [18] As in our case, many open questions remain, in particular concerning the organisation of the molecules in the bulk or at interfaces for the entire accessible concentration range, which will have to be addressed in the future.…”

Section: Discussionmentioning

confidence: 86%

A Novel Pyrene‐Based Fluorescing Amphiphile with Unusual Bulk and Interfacial Properties

et al. 2011

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We have synthesised a new, pyrene-based, low-molecular-mass, amphiphilic molecule that displays a wealth of properties of potential interest for aggregation and interfacial applications. In order to elucidate some of the key properties of this molecule, which consists of a pyrene-containing hydrophobic head and a short PEG-based hydrophilic tail, we investigate herein some aspects of its concentration-dependent behaviour in aqueous solutions. We show that the inclusion of the hydrophobic pyrene group not only provides the molecule with intriguing bulk and interfacial properties down to low concentrations, but also with various means of assessing its aggregation behaviour by means of its well-characterised fluorescence properties. Combining a range of fluorescence techniques with microscopic imaging (optical and Cryo-TEM), interfacial tension measurements and foaming studies, we have been able to identify and characterise three concentration-dependant regimes. At low concentrations, the molecule is dissolved in monomeric form. At intermediate concentrations, labile aggregates are formed, which, at higher concentrations, give way to aggregates containing pre-associated pyrenes. Our measurements strongly imply that the latter aggregates are hexagonally close-packed tubular micelles. In this latter regime we also find a range of micron-sized precipitates. Additionally, the molecule displays strong interfacial activity, yet a surprisingly slow dynamics of interfacial adsorption. Finally, we demonstrate the possibility of using it to visualize interfaces and also create reasonably stable (1 hour) and fluorescing foams.

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“…In the present paper, we report details monolayer characteristics of pyrene mixed with stearic acid at the air-water interface. Pyrene is well known due to intense fluorescence with long life time and strong excimer emission and widely used as phohtophysical probe [9][10][11] . Although pyrene and its derivatives are extensively studied in the restricted geometry of LB film [9][10][11] .…”

Section: Introductionmentioning

confidence: 99%

“…Pyrene is well known due to intense fluorescence with long life time and strong excimer emission and widely used as phohtophysical probe [9][10][11] . Although pyrene and its derivatives are extensively studied in the restricted geometry of LB film [9][10][11] . However details investigations of the monolayer characteristics of pyrene at the air-water interface has never been reported before.…”

Section: Introductionmentioning

confidence: 99%

Monolayer Characteristics of Pyrene Mixed With Stearic Acid at the Air–water Interface

2008

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In the present communication we report the monolayer characteristics of pyrene mixed with stearic acid (SA) at the air-water interface. The monolayer properties are investigated by recording and analyzing the surface pressure-area per molecule isotherm ( A − π ) of the pyrene-SA mixed films. It is observed that the pyrene and SA are miscible in the mixed monolayer. This miscibility/nonideality leads to phase separation between the constituent components (pyrene and SA). BAM image of the mixed monolayer confirms the miscibility or nonideal mixing at the mixed monolayer.

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Unique fluorescence spectra of a disubstituted pyrene surfactant in Langmuir–Blodgett films

Cited by 9 publications

References 14 publications

Ca2+ homeostasis defects and hereditary hearing loss

Ca2+ homeostasis defects and hereditary hearing loss

A Novel Pyrene‐Based Fluorescing Amphiphile with Unusual Bulk and Interfacial Properties

Monolayer Characteristics of Pyrene Mixed With Stearic Acid at the Air–water Interface

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