A tip-enhanced Raman spectroscopy (TERS) system based on an atomic force microscope (AFM) and radially polarized laser beam was developed. A TERS probe with plasmon resonance wavelength matching the excitation wavelength was prepared with the help of dark-field micrographs. The intrinsic photoluminescence (PL) from the silver (Ag)-coated TERS probe induced by localized surface plasmon resonance contains information about the near-field enhanced electromagnetic field intensity of the probe. Therefore, we used the intensity change of Ag PL to evaluate the stability of the Ag-coated probe during TERS experiments. Tracking the Ag PL of the TERS probe was helpful to detect probe damage and hotspot alignment. Our setup was successfully used for the TERS imaging of single-walled carbon nanotubes, which demonstrated that the Ag PL of the TERS probe is a good criterion to assist in the hotspot alignment procedure required for TERS experiments. This method lowers the risk of contamination and damage of the precious TERS probe, making it worthwhile for wide adoption in TERS experiments.

中文翻译：

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通过探针的银光致发光来促进尖端增强拉曼光谱中的热点对准

开发了基于原子力显微镜（AFM）和径向偏振激光束的尖端增强拉曼光谱（TERS）系统。借助于暗场显微照片，制备了具有与激发波长匹配的等离子体共振波长的TERS探针。由局部表面等离子体共振引起的涂银（Ag）的TERS探针的固有光致发光（PL）包含有关探针近场增强电磁场强度的信息。因此，我们使用Ag PL的强度变化来评估TERS实验过程中涂有Ag的探针的稳定性。跟踪TERS探针的Ag PL有助于检测探针损坏和热点对准。我们的设置已成功用于单壁碳纳米管的TERS成像，这表明，TERS探针的Ag PL是帮助进行TERS实验所需的热点比对程序的良好标准。这种方法降低了珍贵的TERS探针受到污染和损坏的风险，因此值得在TERS实验中广泛采用。