Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México.
J Phys Chem B. 2011 Apr 28;115(16):4826-33. doi: 10.1021/jp111985z. Epub 2011 Apr 1.
A nanodrum of an unsupported L-α-phosphatidylcholine bilayer on a ∼7 μm pore was studied using a new experimental setup that permits atomic force microscopy (AFM) in conjunction with the electrical determination of trans-bilayer channels, thus checking its unilamellar character. In these nanodrums, the bilayer engulfs the intruding AFM tip with an adhesion similar to the attraction between two mica supported bilayers brought into close contact. Using this response and the finding of a nonlinear behavior of the Canham-Helfrich elastic model allows for the simultaneous determination of the elastic properties of the membrane. A bending modulus (κ = 1.5 ± 0.6 × 10(-19 )J) and a lateral tension (σ = 1.9 ± 0.7 mN/m) were determined for this case. Most importantly, an adhesion constant (w = 4.6 ± 2.2 mJ/m(2)) was determined from a particular response to deformation of large membrane patches.
在一个约 7 μm 的孔上，研究了一个无支撑的 L-α-磷脂双层的纳米鼓，使用了一种新的实验装置，该装置允许原子力显微镜 (AFM) 与跨双层通道的电测定结合使用，从而检查其单层特征。在这些纳米鼓中，双层将侵入的 AFM 尖端包裹起来，其粘附力类似于两个云母支撑的双层紧密接触时的吸引力。利用这种响应以及 Canham-Helfrich 弹性模型的非线性行为的发现，可以同时确定膜的弹性特性。对于这种情况，确定了弯曲模量 (κ = 1.5 ± 0.6 × 10(-19 )J) 和横向张力 (σ = 1.9 ± 0.7 mN/m)。最重要的是，从对大膜片变形的特定响应中确定了粘附常数 (w = 4.6 ± 2.2 mJ/m(2))。
