Sevastopol State University, St. University, 33, Sevastopol, Russia.
Tomsk State University, Av. Lenina, 36, Tomsk, Russia.
Sci Rep. 2022 Jul 4;12(1):11302. doi: 10.1038/s41598-022-14807-5.
In this work demostrates a unique method for determining the absolute value of the friction force of a nanoobject on the surface of a cell membrane using atomic force microscopy. The tribological properties of membranes of adult human buccal epithelium cells in the presence of a protective adsorption buffer layer of ~ 100 nm on their surface were studied using atomic force microscopy in the contact scanning mode. Local mapping of the tribological characteristics of the surface was carried out, viz. friction F = F(x, y) and adhesion F = F(x, y) forces were measured. Studies of the friction force F on the membrane surface at the nanolevel showed that its value varies discretely with an interval equal to l ≈ 100 nm. It was shown that such discreteness is determined by the interval l of the action of adhesive forces F and indicates the fractal nature of the functional dependence of the friction force on the coordinate F = F(x). Thus, for nano-objects with dimensions ≤ l, the absolute value of F decreases according to a power law with an increase in the size of the object, which contradicts the similar dependence of the friction force for macro-objects in the global approximation.
在这项工作中，展示了一种使用原子力显微镜确定纳米物体在细胞膜表面上摩擦力绝对值的独特方法。使用原子力显微镜在接触扫描模式下研究了表面存在保护性吸附缓冲层约 100nm 的成人人口腔上皮细胞的膜的摩擦学特性。进行了表面摩擦学特性的局部映射，即测量摩擦力 F= F（x，y）和粘附力 F= F（x，y）。在纳米级研究膜表面上的摩擦力 F 表明，其值随等于 l ≈ 100nm 的间隔离散变化。结果表明，这种离散性由粘附力 F 的作用间隔 l 确定，并表明摩擦力对坐标 F= F（x）的函数依赖性的分形性质。因此，对于尺寸小于或等于 l 的纳米物体，F 的绝对值根据物体尺寸的增加而按幂律减小，这与宏观物体在全局近似中的摩擦力的类似依赖性相矛盾。
