Nanophotonic platforms in theory uniquely enable < femtomoles of chiral biological and pharmaceutical molecules to be detected, through the highly localized changes in the chiral asymmetries of the near fields that they induce. However, current chiral nanophotonic based strategies are intrinsically limited because they rely on far field optical measurements that are sensitive to a much larger near field volume, than that influenced by the chiral molecules. Consequently, they depend on detecting small changes in far field optical response restricting detection sensitivities. Here, we exploit an intriguing phenomenon, plasmonic circularly polarized luminescence (PCPL), which is an incisive local probe of near field chirality. This allows the chiral detection of monolayer quantities of a de novo designed peptide, which is not achieved with a far field response. Our work demonstrates that by leveraging the capabilities of nanophotonic platforms with the near field sensitivity of PCPL, optimal biomolecular detection performance can be achieved, opening new avenues for nanometrology.

中文翻译：

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用等离子体圆偏振发光近场探测光学超手性以增强生物检测

理论上，纳米光子平台能够通过它们引起的近场手性不对称性的高度局部化变化，独特地检测 < 飞摩尔的手性生物和药物分子。然而，目前基于手性纳米光子的策略本质上是有限的，因为它们依赖于远场光学测量，这些测量对比受手性分子影响的近场体积大得多的近场体积敏感。因此，它们依赖于检测限制检测灵敏度的远场光学响应的​​微小变化。在这里，我们利用了一种有趣的现象，等离子体圆偏振发光 (PCPL)，它是近场手性的敏锐局部探针。这允许从头检测单层量的手性设计的肽，远场响应无法实现。我们的工作表明，通过利用具有 PCPL 近场灵敏度的纳米光子平台的功能，可以实现最佳的生物分子检测性能，为纳米计量学开辟新途径。