Tip-enhanced Raman spectroscopy (TERS) is a powerful tool for the characterization of surfaces and two-dimensional materials, delivering both topographical and chemical information with nanometer-scale spatial resolution. Atomic force microscopy (AFM)–TERS combines AFM with a Raman spectrometer and is a very versatile technique, capable of working in vacuum, air, and liquid, and on a variety of different samples. A metalized AFM tip is necessary in order to take advantage of the plasmonic enhancement. The most commonly used metal is Ag, thanks to its high plasmonic activity in the visible range. Unfortunately, though, the tip metallization process is still challenging and not fully reliable, yielding inconsistent enhancement factors even within the same batch of tips; as a consequence, many tips are usually prepared at once (for a single experiment), to ensure that at least one of them is sufficiently active. As the lifetime of an unprotected, Ag-coated plasmonic probe is only a few hours, the procedure is inefficient and results in a substantial waste of materials and money. In this work, we establish a cleaning routine to effectively re-use Ag-coated AFM–TERS probes, drastically reducing costs without compromising the quality of the experimental results.

中文翻译：

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EXPRESS：基于原子力显微镜的尖端增强拉曼光谱的尖端回收

尖端增强拉曼光谱 (TERS) 是表征表面和二维材料的强大工具，可提供具有纳米级空间分辨率的地形和化学信息。原子力显微镜 (AFM) – TERS 将 AFM 与拉曼光谱仪相结合，是一种用途广泛的技术，能够在真空、空气和液体以及各种不同的样品上工作。为了利用等离子体增强，金属化的 AFM 尖端是必要的。最常用的金属是银，因为它在可见光范围内具有高等离子体活性。然而不幸的是，尖端金属化过程仍然具有挑战性且不完全可靠，即使在同一批次的尖端中也会产生不一致的增强因子；作为结果，通常一次准备许多提示（对于单个实验），以确保其中至少一个足够活跃。由于未受保护的、涂有银的等离子探针的寿命只有几个小时，因此该过程效率低下并导致材料和金钱的大量浪费。在这项工作中，我们建立了一个清洁程序，以有效地重复使用 Ag 涂层的 AFM-TERS 探针，在不影响实验结果质量的情况下大幅降低成本。