Zverzhinetsky Marina, Krivitsky Vadim, Patolsky Fernando
School of Chemistry, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, 69978, Israel.
School of Chemistry, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, 69978, Israel.
Biosens Bioelectron. 2020 Dec 15;170:112658. doi: 10.1016/j.bios.2020.112658. Epub 2020 Sep 28.
A wide range of fields, starting from basic research in life sciences and up to medical applications, are highly interested in the investigation and detection of biomarkers in all their forms, including proteins. However, direct analytical detection of specific protein biomarkers from a physiological biosample is still extremely challenging due to the abundant variety and amount of its components. In this work, we apply the chemically-controlled antigen-dissociation detection approach on silicon nanowires-based field-effect transistor arrays, by creating a suitable 'chemical environment' which enabled the clear-cut splitting of the dissociation regime window into two sub-regimes, thus allowing the complete washing of the nonspecifically adsorbed salts and biomolecules, while significantly delaying the dissociation of specific surface-bounded antigen-antibody pairs. This was accomplished by the addition of the water-miscible organic reagent ethylene glycol, which radically alters the properties of the aqueous solvent, by means of dramatically reducing its interactions with the particular protein antigen, and thus allowing for the increase in the antigen-antibody interaction strength. This in turn, deeply reduces the solubility of the surface-bound protein molecules and increases their interaction with the specific receptor antibody units, which brings to a substantial delay in the antibody-antigen dissociation behavior. This phenomenon allows the clear-cut splitting of the dissociation regime window and the quantitative and accurate analysis of proteins in physiological samples. We demonstrated the direct and quantitative detection of protein biomarkers, down to concentrations in the fM range, from unprocessed whole blood minuscule samples of only a few microliters. This work is the first demonstration on the chemically-controlled dissociation kinetics of antibody-antigen pairs by the use of water-miscible organic solvent mixtures, and its application in the direct ultrasensitive detection of protein biomarkers from whole blood samples.
从生命科学的基础研究到医学应用，广泛的领域都对各种形式生物标志物（包括蛋白质）的研究和检测高度感兴趣。然而，由于生理生物样品中成分种类繁多且数量丰富，直接从生理生物样品中分析检测特定蛋白质生物标志物仍然极具挑战性。在这项工作中，我们将化学控制的抗原解离检测方法应用于基于硅纳米线的场效应晶体管阵列，通过创建合适的“化学环境”，使解离区域窗口清晰地分为两个子区域，从而能够完全洗去非特异性吸附的盐和生物分子，同时显著延迟特异性表面结合的抗原 - 抗体对的解离。这是通过添加与水混溶的有机试剂乙二醇来实现的，乙二醇通过大幅降低其与特定蛋白质抗原的相互作用，从根本上改变了水性溶剂的性质，从而增加了抗原 - 抗体相互作用强度。这进而极大地降低了表面结合蛋白质分子的溶解度，并增加了它们与特异性受体抗体单元的相互作用，导致抗体 - 抗原解离行为大幅延迟。这种现象使得解离区域窗口能够清晰划分，并能对生理样品中的蛋白质进行定量准确分析。我们展示了从仅几微升未经处理的全血微量样品中直接定量检测低至飞摩尔浓度范围的蛋白质生物标志物。这项工作首次证明了通过使用与水混溶的有机溶剂混合物来化学控制抗体 - 抗原对的解离动力学，及其在从全血样品中直接超灵敏检测蛋白质生物标志物方面的应用。
