J Am Chem Soc. 2018 Oct 31;140(43):14134-14143. doi: 10.1021/jacs.8b07325. Epub 2018 Oct 22.
The spatial arrangement of target and probe molecules on the biosensor is a key aspect of the biointerface structure that ultimately determines the properties of interfacial molecular recognition and the performance of the biosensor. However, the spatial patterns of single molecules on practical biosensors have been unknown, making it difficult to rationally engineer biosensors. Here, we have used high-resolution atomic force microscopy to map closely spaced individual probes as well as discrete hybridization events on a functioning electrochemical DNA sensor surface. We also applied spatial statistical methods to characterize the spatial patterns at the single molecule level. We observed the emergence of heterogeneous spatiotemporal patterns of surface hybridization of hairpin probes. The clustering of target capture suggests that hybridization may be enhanced by proximity of probes and targets that are about 10 nm away. The unexpected enhancement was rationalized by the complex interplay between the nanoscale spatial organization of probe molecules, the conformational changes of the probe molecules, and target binding. Such molecular level knowledge may allow one to tailor the spatial patterns of the biosensor surfaces to improve the sensitivity and reproducibility.
生物传感器上靶标和探针分子的空间排列是生物界面结构的一个关键方面，它最终决定了界面分子识别的性质和生物传感器的性能。然而，实际生物传感器上单个分子的空间模式尚不清楚，这使得生物传感器的合理设计变得困难。在这里，我们使用高分辨率原子力显微镜在功能电化学 DNA 传感器表面上绘制了紧密间隔的单个探针以及离散的杂交事件。我们还应用空间统计方法来表征单分子水平的空间模式。我们观察到发夹探针表面杂交的不均匀时空模式的出现。靶标捕获的聚类表明，大约 10nm 距离的探针和靶标之间的接近可能会增强杂交。这种意想不到的增强可以通过探针分子的纳米级空间组织、探针分子的构象变化和靶标结合之间的复杂相互作用来合理化。这种分子水平的知识可以使人们能够调整生物传感器表面的空间模式，以提高灵敏度和重现性。
