Wu Zhihua, Chen Hongbing, Dong Yaming, Mao Huiling, Sun Jielin, Chen Shenfu, Craig Vincent S J, Hu Jun
State Key Laboratory of Food Sci. & Tech., Nanchang University, Nanchang, China.
J Colloid Interface Sci. 2008 Dec 1;328(1):10-4. doi: 10.1016/j.jcis.2008.08.064. Epub 2008 Sep 9.
Here we demonstrate that nanobubbles can be used as cleaning agents both for the prevention of surface fouling and for defouling surfaces. In particular nanobubbles can be used to remove proteins that are already adsorbed to a surface, as well as for the prevention of nonspecific adsorption of proteins. Nanobubbles were produced on highly oriented pyrolytic graphite (HOPG) surfaces electrochemically and observed by atomic force microscopy (AFM). Nanobubbles produced by electrochemical treatment for 20 s before exposure to bovine serum albumin (BSA) were found to decrease protein coverage by 26-34%. Further, pre-adsorbed protein on a HOPG surface was also removed by formation of electrochemically produced nanobubbles. In AFM images, the coverage of BSA was found to decrease from 100% to 82% after 50 s of electrochemical treatment. The defouling effect of nanobubbles was also investigated using radioactively labeled BSA. The amount of BSA remaining on a stainless steel surface decreased by approximately 20% following 3 min of electrochemical treatment and further cycles of treatment effectively removed more BSA from the surface. In situ observations indicate that the air-water interface of the nanobubble is responsible for the defouling action of nanobubbles.
在此我们证明，纳米气泡可用作清洁剂，既用于防止表面污染，也用于清除已被污染的表面。特别是，纳米气泡可用于去除已吸附在表面的蛋白质，以及防止蛋白质的非特异性吸附。通过电化学方法在高度取向热解石墨（HOPG）表面产生纳米气泡，并通过原子力显微镜（AFM）进行观察。发现在暴露于牛血清白蛋白（BSA）之前经过20秒电化学处理产生的纳米气泡可使蛋白质覆盖率降低26 - 34%。此外，通过电化学产生的纳米气泡的形成，也可去除HOPG表面预先吸附的蛋白质。在AFM图像中，经过50秒电化学处理后，发现BSA的覆盖率从100%降至82%。还使用放射性标记的BSA研究了纳米气泡的去污效果。经过3分钟电化学处理后，不锈钢表面残留的BSA量减少了约20%，进一步的处理循环有效地从表面去除了更多的BSA。原位观察表明，纳米气泡的气 - 水界面是纳米气泡去污作用的原因。
