Deactivation of lipopolysaccharide by Ar and H2 inductively coupled low-pressure plasma
Deactivation of lipopolysaccharide by Ar and H2 inductively coupled low-pressure plasma
复制标题
Ar 和 H2 感应耦合低压等离子体使脂多糖失活
DOI：
10.1088/0022-3727/47/4/045202
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
G. Oehrlein
中科院分区：
文献类型：
--
作者：
E. Bartis;C. Barrett;Ting;Ning Ning;Jhih;D. Graves;Joonil Seog;G. Oehrlein
利用电感耦合等离子体系统，我们研究了直接等离子体，等离子体产生的高能光子在紫外和真空紫外（UV/VUV），和自由基处理对脂多糖（LPS）的影响。LPS是在革兰氏阴性菌的外膜中发现的生物分子，并且是由多糖和脂质A组成的免疫系统的有效刺激剂，所述脂质A含有六个脂肪链。通过椭圆偏振法监测旋涂在硅上的LPS膜厚度，同时通过X射线光电子能谱（XPS）表征处理前后的表面化学。此外，在血浆处理后，使用酶联免疫吸附试验在（a）敏感方案（LPS浓度低于µM）和（B）批量方案（LPS浓度高于µM）下测量生物活性。直接等离子体处理导致在Ar和H2进料气体中LPS的快速蚀刻和失活。为了检查UV/VUV光子的效果，将截止波长为112 nm的长通滤波器放置在样品上。H2 UV/VUV处理由于原子和分子UV/VUV发射而导致材料去除和失活，而Ar UV/VUV处理显示出最小的影响，因为Ar等离子体在探索的透射波长范围内不发射UV/VUV光子。有趣的是，自由基处理去除的材料可以忽略不计，但会导致失活。基于LPS的两亲性结构，我们预期在样品制备期间在空气-水界面处形成富含脂质A的表面层，多糖层在下面。XPS表明，在直接和UV/VUV条件下的H2等离子体处理通过去除膜中的C-O和O-C = O键引起氧耗尽，这在Ar处理中不会发生。对这些基团的损伤可以去除有助于LPS致热原性的脂肪链。从Ar和H2等离子体的自由基处理去除脂肪族碳从近表面，表明中性物种的重要作用。
Using an inductively coupled plasma system, we study the effects of direct plasma, plasma-generated high-energy photons in the ultraviolet and vacuum ultraviolet (UV/VUV), and radical treatments on lipopolysaccharide (LPS). LPS is a biomolecule found in the outer membrane of Gram-negative bacteria and a potent stimulator of the immune system composed of polysaccharide and lipid A, which contains six aliphatic chains. LPS film thickness spun on silicon was monitored by ellipsometry while the surface chemistry was characterized before and after treatments by x-ray photoelectron spectroscopy (XPS). Additionally, biological activity was measured using an enzyme-linked immunosorbent assay under (a) a sensitive regime (sub-µM concentrations of LPS) and (b) a bulk regime (above µM concentrations of LPS) after plasma treatments. Direct plasma treatment causes rapid etching and deactivation of LPS in both Ar and H2 feed gases. To examine the effect of UV/VUV photons, a long-pass filter with a cut-off wavelength of 112 nm was placed over the sample. H2 UV/VUV treatment causes material removal and deactivation due to atomic and molecular UV/VUV emission while Ar UV/VUV treatment shows minimal effects as Ar plasma does not emit UV/VUV photons in the transmitted wavelength range explored. Interestingly, radical treatments remove negligible material but cause deactivation. Based on the amphiphilic structure of LPS, we expect a lipid A rich surface layer to form at the air–water interface during sample preparation with polysaccharide layers underneath. XPS shows that H2 plasma treatment under direct and UV/VUV conditions causes oxygen depletion through removal of C–O and O–C = O bonds in the films, which does not occur in Ar treatments. Damage to these groups can remove aliphatic chains that contribute to the pyrogenicity of LPS. Radical treatments from both Ar and H2 plasmas remove aliphatic carbon from the near-surface, demonstrating the important role of neutral species.
影响因子：
56.9
作者：
NIKAIDO, H
通讯作者：
NIKAIDO, H
由脂多糖和细菌磷脂组成的支撑双层结构：筏形成及其对细菌耐药性的影响。
影响因子：
3.4
作者：
Tong,Jihong;McIntosh,ThomasJ
通讯作者：
McIntosh,ThomasJ