The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Yi He Yuan Road #5, Haidian District, Beijing 100871, PR China.
Colloids Surf B Biointerfaces. 2011 Feb 1;82(2):443-9. doi: 10.1016/j.colsurfb.2010.09.018. Epub 2010 Oct 8.
The deposition kinetics of RNA extracted from both virus and bacteria on silica surfaces were examined in both monovalent (NaCl) and divalent (CaCl(2)) solutions under a wide range of environmentally relevant ionic strength and pH conditions by utilizing a quartz crystal microbalance with dissipation (QCM-D). To better understand the RNA deposition mechanisms, QCM-D data were complemented by diffusion coefficients and zeta potentials of RNA as a function of examined solution chemistry conditions. Favorable deposition of RNA on poly-l-lysine-coated (positively charged) silica surfaces was governed by the convective-diffusive transport of RNA to the surfaces. The deposition kinetics of RNA on bare silica surfaces were controlled by classic Derjaguin-Landau-Verwey-Overbeek (DLVO) interactions. The presence of divalent cations (Ca(2+)) in solutions greatly enhanced the deposition kinetics of RNA on silica surfaces. Solution pH also affected the deposition behavior of RNA on silica surfaces. Release experiments showed that detachment of RNA from silica surfaces was significant in NaCl solutions, whereas, the deposited RNA on silica surfaces in CaCl(2) solutions was more likely to be irreversible.
通过利用石英晶体微天平（QCM-D），在单离子（NaCl）和双离子（CaCl(2)）溶液中，在广泛的环境相关离子强度和 pH 条件下，检测了从病毒和细菌中提取的 RNA 在二氧化硅表面的沉积动力学。为了更好地理解 RNA 沉积机制，将 QCM-D 数据与 RNA 的扩散系数和 ζ 电位补充为检查的溶液化学条件的函数。带正电荷的聚-l-赖氨酸涂层二氧化硅表面对 RNA 的有利沉积是由 RNA 向表面的对流扩散输运控制的。在裸二氧化硅表面上，RNA 的沉积动力学由经典的德加古因-兰道-范德瓦尔斯（DLVO）相互作用控制。溶液中二价阳离子（Ca(2+））的存在极大地增强了 RNA 在二氧化硅表面上的沉积动力学。溶液 pH 值也影响了 RNA 在二氧化硅表面上的沉积行为。释放实验表明，在 NaCl 溶液中，RNA 从二氧化硅表面的脱落非常显著，而在 CaCl(2)溶液中沉积在二氧化硅表面的 RNA 更可能是不可逆的。
