The development of miniaturized electronics has led to the design and construction of powerful experimental platforms capable of measuring electronic properties to the level of single molecules, along with new theoretical concepts to aid in the interpretation of the data. A new area of activity is now emerging concerned with repurposing the tools of molecular electronics for applications in chemical and biological analysis. Single-molecule junction techniques, such as the scanning tunnelling microscope break junction and related single-molecule circuit approaches have a remarkable capacity to transduce chemical information from individual molecules, sampled in real time, to electrical signals. In this Review, we discuss single-molecule junction approaches as emerging analytical tools for the chemical and biological sciences. We demonstrate how these analytical techniques are being extended to systems capable of probing chemical reaction mechanisms. We also examine how molecular junctions enable the detection of RNA, DNA, and traces of proteins in solution with limits of detection at the zeptomole level.

微型电子学的发展导致了强大的实验平台的设计和构建，这些平台能够测量单分子水平的电子特性，并提供新的理论概念来帮助解释数据。现在正在出现一个新的活动领域，涉及重新利用分子电子学工具在化学和生物分析中的应用。单分子结技术，例如扫描隧道显微镜断裂结和相关的单分子电路方法，具有将实时采样的单个分子的化学信息转换为电信号的非凡能力。在这篇综述中，我们讨论单分子连接方法作为化学和生物科学的新兴分析工具。我们展示了如何将这些分析技术扩展到能够探测化学反应机制的系统。我们还研究了分子连接如何能够检测溶液中的 RNA、DNA 和痕量蛋白质，且检测限在 Zeptomole 水平。