中文摘要：

目的：考察低温空气等离子体对医用聚四氟乙烯（PTFE）表面大肠杆菌的灭活效果以及灭菌机理。方法：采用Langmuir双电子探针和电子自旋共振（ESR）诊断技术分别定量测定了远程低温空气等离子体场中各活性物种的分布。并通过扫描电镜（SEM）对灭菌后细胞破碎情况进行观察，细胞泄漏物质检测，反映腔温度变化和紫外线对灭菌影响分析其灭菌机理。结果：本实验条件下，空气等离子灭菌的最适宜操作参数为，放电功率100W，空气流量40sccm，放电时间120s。通过细胞形态学的观察和蛋白质泄漏量检测，结果证实等离子体处理后的大肠杆菌细胞肿胀、疏松，因此可以得出空气等离子体对大肠杆菌的灭菌机理为，电子、离子、自由基等活性粒子作用于细胞壁和细胞膜，使之肿胀、疏松、断裂，通透性增加，内容物流出是导致大肠杆菌死亡的直接原因。结论：空气等离子体灭菌效果受等离子体处理参数的影响。

英文摘要：

Objective：To investigate the remote air plasma germicidal effect of Escherichia coli on the surface of medical Poly （tetrafluoroethylene） （PTFE） and mechanisms of sterilization. Methods：The distribution of active particles was measured by double Langmuir electron probe and Electron-Spin Resonance （ESR） diagnosis in air plasma. The configuration distinction of the Escherichia coli before and after plasma treatment was observed by using scanning electron microscopy （SEM）. To find the inactivation mechanisms of air plasma, protein leakage content measurement, change of temperature in reactor and effect of ultraviolet radiation to sterilization were performed. Results：The optimal inactivation of Escherichia coli was achieved when plasma treatment parameters were set at RF power 100 watts, treatment time 120 seconds, and air gas flow rate 40 standard cubic centimeters per minute. Observations on the configuration of the bacteria and the leakages of protein proved that cells turned swelled and loosen. The inactivation mechanisms were that electrons, ions and radicals destroyed the cell wall and membrane, resulting in bacteria swelling, loosing and fi＇acturing. The increase of permeability led to the leakage of proteins and other materials in the cell and ultimately the death of Escherichia coli. Conclusions：The remote air plasma germicidal effect of low-temperature air plasma is affected by plasma treatment parameters.