Siam Hussain, Johann Eduardo Maradiaga Rivas, Wen-Chi Tseng, R. Tsay, Boris Noskov, Giuseppe Loglio, Shi-Yow Lin
{"title":"Measurement of Dilational Modulus of an Adsorbed BSA Film Using Pendant Bubble Tensiometry: From a Clean Interface to Saturation","authors":"Siam Hussain, Johann Eduardo Maradiaga Rivas, Wen-Chi Tseng, R. Tsay, Boris Noskov, Giuseppe Loglio, Shi-Yow Lin","doi":"10.3390/colloids8010004","DOIUrl":null,"url":null,"abstract":"Two open issues on the measurement of the dilational modulus (E) for an adsorbed protein film during the adsorption process have been unacknowledged: how E varies during the adsorption and the length of time needed to attain a stable E value. A new approach for detecting the E variation from a clean air–water interface to saturated film and estimating the time needed to reach a saturated state was proposed. A pendant bubble tensiometer was utilized for measuring the relaxations of surface tension (ST) and surface area (SA), and the E was evaluated from the relaxation data of minute distinct perturbances. The data showed a clear variation in E during the BSA adsorption: E sharply decreased to a minimum at the early stage of BSA adsorption; then, it rose from this minimum and oscillated for a while before reaching an E corresponding to a saturated BSA film after a significant duration. The adsorbed BSA film took ~35 h to reach its saturated state, which was much longer than the reported lifetime of the adsorbed film in the literature. A rapid surface perturbation (forced bubble expansion/compression) could change the E, causing a significant drop in E followed by a slow increase to the original stable value.","PeriodicalId":10433,"journal":{"name":"Colloids and Interfaces","volume":null,"pages":null},"PeriodicalIF":2.5000,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Colloids and Interfaces","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3390/colloids8010004","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Two open issues on the measurement of the dilational modulus (E) for an adsorbed protein film during the adsorption process have been unacknowledged: how E varies during the adsorption and the length of time needed to attain a stable E value. A new approach for detecting the E variation from a clean air–water interface to saturated film and estimating the time needed to reach a saturated state was proposed. A pendant bubble tensiometer was utilized for measuring the relaxations of surface tension (ST) and surface area (SA), and the E was evaluated from the relaxation data of minute distinct perturbances. The data showed a clear variation in E during the BSA adsorption: E sharply decreased to a minimum at the early stage of BSA adsorption; then, it rose from this minimum and oscillated for a while before reaching an E corresponding to a saturated BSA film after a significant duration. The adsorbed BSA film took ~35 h to reach its saturated state, which was much longer than the reported lifetime of the adsorbed film in the literature. A rapid surface perturbation (forced bubble expansion/compression) could change the E, causing a significant drop in E followed by a slow increase to the original stable value.
在吸附过程中测量被吸附蛋白质薄膜的扩张模量(E)方面,有两个尚未解决的问题:E 在吸附过程中如何变化,以及获得稳定 E 值所需的时间长度。我们提出了一种新方法来检测从清洁空气-水界面到饱和薄膜的 E 值变化,并估算达到饱和状态所需的时间。利用悬挂式气泡张力计测量表面张力(ST)和表面积(SA)的弛豫,并根据微小不同扰动的弛豫数据评估 E。数据显示,在吸附 BSA 的过程中 E 有明显的变化:在吸附 BSA 的初期,E 值急剧下降至最小值;随后,E 值从最小值开始上升并震荡了一段时间,在相当长的一段时间后达到与饱和 BSA 膜相对应的 E 值。吸附的 BSA 薄膜需要约 35 小时才能达到饱和状态,这比文献中报道的吸附薄膜的寿命要长得多。快速的表面扰动(强制气泡膨胀/压缩)会改变 E 值,导致 E 值显著下降,然后缓慢上升到原始稳定值。