Microwave measurement of giant unilamellar vesicles in aqueous solution
| Autor: | Taghi Darroudi, William F. Delaney, Pingshan Wang, Yan Cui |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Permittivity Materials science Microfluidics Analytical chemistry lcsh:Medicine 02 engineering and technology Dielectric Permeability Article 03 medical and health sciences Resonator chemistry.chemical_compound lcsh:Science Microwaves POPC Unilamellar Liposomes Multidisciplinary Aqueous solution Vesicle lcsh:R Water 021001 nanoscience & nanotechnology Sphingomyelins 030104 developmental biology Membrane Cholesterol chemistry Phosphatidylcholines lcsh:Q 0210 nano-technology Microwave |
| Zdroj: | Scientific Reports Scientific Reports, Vol 8, Iss 1, Pp 1-8 (2018) |
| ISSN: | 2045-2322 |
| Popis: | A microwave technique is demonstrated to measure floating giant unilamellar vesicle (GUV) membranes in a 25 μm wide and 18.8 μm high microfluidic channel. The measurement is conducted at 2.7 and 7.9 GHz, at which a split-ring resonator (SRR) operates at odd modes. A 500 nm wide and 100 μm long SRR split gap is used to scan GUVs that are slightly larger than 25 μm in diameter. The smaller fluidic channel induces flattened GUV membrane sections, which make close contact with the SRR gap surface. The used GUVs are synthesized with POPC (16:0–18:1 PC 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine), SM (16:0 Egg Sphingomyelin) and cholesterol at different molecular compositions. It is shown that SM and POPC bilayers have different dielectric permittivity values, which also change with measurement frequencies. The obtained membrane permittivity values, e.g. 73.64-j6.13 for POPC at 2.7 GHz, are more than 10 times larger than previously reported results. The discrepancy is likely due to the measurement of dielectric polarization parallel with, other than perpendicular to, the membrane surface. POPC and SM-rich GUV surface sections are also clearly identified. Further work is needed to verify the obtained large permittivity values and enable accurate analysis of membrane composition. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|