在大自然中,界面内的受体-配体结合反应通常通过调节界面受体/配体的时空分布来获得最佳的结合动力学和热力学。受此启发,我们报告了一种分层流体界面（HieFluidFace）来调节界面配体的时空分布，以增加界面结合反应的速率和热力学有利性。每个球形适体（SAPT）锚定在支撑的脂质双层上，没有流动性，作为“岛”，并被许多具有自由流动性的荧光适体(FAPT)包围，如“木筏”。这种配体“岛筏”模型为快速结合提供了大的反应性横截面。SAPT和FAPT的协同多价改善了紧密捕获的界面亲和力。此外，FAPT在结合位点处积累以结合细胞受体，并具有成簇的荧光以“减轻”细胞以进行直接鉴定。因此，微流控芯片中的HieFluidFace实现了从临床样品中高效捕获和识别循环肿瘤细胞，提供了一个新的范式来优化界面结合反应的动力学和热力学。
In nature, regulation of the spatiotemporal distribution of interfacial receptors and ligands leads to optimum binding kinetics and thermodynamics of receptor-ligand binding reactions within interfaces. Inspired by this, we report a hierarchical fluid interface (HieFluidFace) to regulate the spatiotemporal distribution of interfacial ligands to increase the rate and thermodynamic favorability of interfacial binding reactions. Each aptamer-functionalized gold nanoparticle, termed spherical aptamer (SAPT), is anchored on a supported lipid bilayer without fluidity, like an \"island\", and is surrounded by many fluorescent aptamers (FAPTs) with free fluidity, like \"rafts\". Such ligand \"island-rafts\" model provides a large reactive cross-section for rapid binding to cellular receptors. The synergistic multivalency of SAPTs and FAPTs improves interfacial affinity for tight capture. Moreover, FAPTs accumulate at binding sites to bind to cellular receptors with clustered fluorescence to \"lighten\" cells for direct identification. Thus, HieFluidFace in a microfluidic chip achieves high-performance capture and identification of circulating tumor cells from clinical samples, providing a new paradigm to optimize the kinetics and thermodynamics of interfacial binding reactions.
