Critical revision of apparent dielectric constants calculations in lipid-water interfaces
In a previous work we used the Stokes shift of two fluorescent probes, dansyldihexadecylamine (DA) and dansylphosphatidylethanolamine (DPE), to study the changes of phospholipid vesicles interfacial polarity on lipid composition and temperature (Bernik, D. L., and Negri, R. M., J. Colloid Interface...
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2000
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219797_v226_n2_p364_MartinNegri http://hdl.handle.net/20.500.12110/paper_00219797_v226_n2_p364_MartinNegri |
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paper:paper_00219797_v226_n2_p364_MartinNegri2023-06-08T14:44:54Z Critical revision of apparent dielectric constants calculations in lipid-water interfaces Apparent dielectric constants Fluorescent probes Liposomes Membrane-water interface article dielectric constant fluorescence mathematical analysis priority journal temperature In a previous work we used the Stokes shift of two fluorescent probes, dansyldihexadecylamine (DA) and dansylphosphatidylethanolamine (DPE), to study the changes of phospholipid vesicles interfacial polarity on lipid composition and temperature (Bernik, D. L., and Negri, R. M., J. Colloid Interface Sci. 203, 97 (1998)). Here, the experimental data are used to critically revisit the procedure commonly followed to obtain the so-called 'apparent dielectric constant', ε(s)/(app), using the Lippert-Mataga equation. We found that anomalous values for ε(s)/(app), such as negative or extremely large values around 100, can be obtained at the membrane-water interface. The origin of those values is discussed and numerical simulations regarding the limitations and assumptions of the procedure are performed. It is shown that as the Stokes shift procedure renders information on the electric field due to orientational dipoles sensed by the probe, the recovered ε(s)/(app) values are dependent on the local refractive index estimation. The results remark on a mathematical basis the cautions that must be taken when physical properties are inferred from experimental data in colloidal systems. (C) 2000 Academic Press. 2000 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219797_v226_n2_p364_MartinNegri http://hdl.handle.net/20.500.12110/paper_00219797_v226_n2_p364_MartinNegri |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Apparent dielectric constants Fluorescent probes Liposomes Membrane-water interface article dielectric constant fluorescence mathematical analysis priority journal temperature |
| spellingShingle |
Apparent dielectric constants Fluorescent probes Liposomes Membrane-water interface article dielectric constant fluorescence mathematical analysis priority journal temperature Critical revision of apparent dielectric constants calculations in lipid-water interfaces |
| topic_facet |
Apparent dielectric constants Fluorescent probes Liposomes Membrane-water interface article dielectric constant fluorescence mathematical analysis priority journal temperature |
| description |
In a previous work we used the Stokes shift of two fluorescent probes, dansyldihexadecylamine (DA) and dansylphosphatidylethanolamine (DPE), to study the changes of phospholipid vesicles interfacial polarity on lipid composition and temperature (Bernik, D. L., and Negri, R. M., J. Colloid Interface Sci. 203, 97 (1998)). Here, the experimental data are used to critically revisit the procedure commonly followed to obtain the so-called 'apparent dielectric constant', ε(s)/(app), using the Lippert-Mataga equation. We found that anomalous values for ε(s)/(app), such as negative or extremely large values around 100, can be obtained at the membrane-water interface. The origin of those values is discussed and numerical simulations regarding the limitations and assumptions of the procedure are performed. It is shown that as the Stokes shift procedure renders information on the electric field due to orientational dipoles sensed by the probe, the recovered ε(s)/(app) values are dependent on the local refractive index estimation. The results remark on a mathematical basis the cautions that must be taken when physical properties are inferred from experimental data in colloidal systems. (C) 2000 Academic Press. |
| title |
Critical revision of apparent dielectric constants calculations in lipid-water interfaces |
| title_short |
Critical revision of apparent dielectric constants calculations in lipid-water interfaces |
| title_full |
Critical revision of apparent dielectric constants calculations in lipid-water interfaces |
| title_fullStr |
Critical revision of apparent dielectric constants calculations in lipid-water interfaces |
| title_full_unstemmed |
Critical revision of apparent dielectric constants calculations in lipid-water interfaces |
| title_sort |
critical revision of apparent dielectric constants calculations in lipid-water interfaces |
| publishDate |
2000 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219797_v226_n2_p364_MartinNegri http://hdl.handle.net/20.500.12110/paper_00219797_v226_n2_p364_MartinNegri |
| _version_ |
1768542067117522944 |