Chiral sensing of single molecules is crucial for understanding chirality and its biomedical applications. Current technologies lack single-molecule sensitivity. This research overcomes this limitation by designing a tunable chiral supramolecular plasmonic system using helical oligoamide sequences (OS) and a nanoparticle-on-mirror (NPOM) resonator. The design enhances chiral sensitivity in the quantum tunneling regime due to strong Coulomb interactions between chiral OSs and achiral NPOMs, and enhancement from tunneling electrons. A minimum of four molecules per Au particle can be detected, enabling enantiomeric excess detection within a monolayer, showing potential for single-molecule chiral sensing.

Chi Zhang, Huatian Hu, Chunmiao Ma, Yawen Li, Xujie Wang, Dongyao Li, Artur Movsesyan, Zhiming Wang, Alexander Govorov, Quan Gan, Tao Ding