Abstract

The effect of Escherichia coli (E. coli) cells on two phospholipids [dipalmitoyl phosphatidylcholine (DPPC) and dimyristoyl phosphatidylcholine (DMPC)] monolayers at the surface of a 1.5 wt% NaCl salt solution has been investigated using surface tension measurement and Brewster angle microscopy. The results showed that a DPPC monolayer that has an elastic structure was changed in morphology by interaction with E. coli cells, whereas a DMPC monolayer that has an expandable structure did not change in morphology. In particular, the morphology changed significantly around the liquid-expanded (LE)–liquid-condensed (LC) phase transition point for the DPPC monolayer. It was found that the LE–LC phase transition range in a DPPC monolayer was sensitive to influence from the outside of the monolayer such as the action of E. coli cells. Such a monolayer has the potential for application as a membrane sensor for detecting a small amount of bacteria in a short time.

Graphic abstract

摘要

的效果大肠杆菌（大肠杆菌）细胞上的两个磷脂[二棕榈酰磷脂酰胆碱（DPPC）和二肉豆蔻酰磷脂酰胆碱（DMPC）]在1.5重量％的氯化钠盐溶液的表面单层已经使用表面张力测量和布鲁斯特角显微镜研究. 结果表明，通过与大肠杆菌的相互作用，具有弹性结构的 DPPC 单层在形态上发生了变化细胞，而具有可扩展结构的 DMPC 单层在形态上没有变化。特别是，DPPC 单层的形态在液体膨胀（LE）-液体冷凝（LC）相变点附近发生了显着变化。发现 DPPC 单层中的 LE-LC 相变范围对来自单层外部的影响敏感，例如大肠杆菌细胞的作用。这种单层有可能用作膜传感器，用于在短时间内检测少量细菌。

图形摘要