The incorporation of responsive elements into photonic crystals is an effective strategy for fabricating active optical components to be used as sensors, actuators, and modulators. In particular, the combination of simple multilayered dielectric mirrors with optically responsive plasmonic materials has proven to be successful. Recently, Tamm plasmon (TP) modes have emerged as powerful tools for these purposes. These modes arise at the interface between a distributed Bragg reflector (DBR) and a plasmonic layer and can be excited at a normal incidence angle. Although the TP field is located usually at the DBR/metal interface, recent studies have demonstrated that nanoscale corrugation of the metal layer permits access to the TP mode from outside, thus opening exciting perspectives for many real-life applications. In this study, we show that the TP resonance obtained by capping a DBR with a nanostructured layer of silver is responsive to Escherichia coli. Our data indicate that the modification of the TP mode originates from the well-known capability of silver to interact with bacteria, within a process in which the release of Ag⁺ ions leaves an excess of negative charge in the metal lattice. Finally, we exploited this effect to devise a case study in which we optically differentiated between the presence of proliferative and nonproliferative bacteria using the TP resonance as a read-out. These findings make these devices promising all-optical probes for bacterial metabolic activity, including their response to external stressors.

中文翻译：

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塔姆等离子体共振作为银/细菌相互作用的光学指纹

将响应元件结合到光子晶体中是制造用作传感器、执行器和调制器的有源光学元件的有效策略。特别是，简单的多层介电镜与光学响应等离子体材料的组合已被证明是成功的。最近，Tamm 等离子体 (TP) 模式已成为用于这些目的的强大工具。这些模式出现在分布式布拉格反射器 (DBR) 和等离子体层之间的界面处，并且可以在法向入射角下被激发。尽管 TP 场通常位于 DBR/金属界面，但最近的研究表明，金属层的纳米级波纹允许从外部访问 TP 模式，从而为许多现实生活应用开辟了令人兴奋的前景。在这项研究中，大肠杆菌。^{我们的数据表明，TP 模式的改变源于众所周知的银与细菌相互作用的能力，在这个过程中，Ag +}离子的释放会在金属晶格中留下过量的负电荷。最后，我们利用这种效应设计了一个案例研究，在该案例研究中，我们使用 TP 共振作为读数来光学区分增殖性和非增殖性细菌的存在。这些发现使这些设备有望成为细菌代谢活动的全光探针，包括它们对外部压力源的反应。