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Scanning tunneling microscopy‐based tip‐enhanced Raman spectroscopy (TERS) is a powerful analytical technique for surface characterization, providing both topological and chemical information with sub‐nm spatial resolution, well below the diffraction limit of light. In order to take advantage of plasmonic activity, it is necessary to use silver (Ag) probes due to their plasmonic range in the visible region. However, the Ag probe fabrication process remains challenging and is not yet standardized in practice, leading to inconsistent enhancements even for two similar types of tips prepared consecutively. In this work, we demonstrate an alternative way to reuse and recycle a plasmonic tip for distinct molecular systems inside an ultrahigh vacuum (UHV). We provide evidence of the ability to recycle tips without compromising the TERS experimental results. A long‐term preservation (>2 months) of plasmonically active probes inside UHV is demonstrated.

 

The ability to directly probe the adsorption configurations of organic regioisomeric molecules, specifically nonplanar isomers, on well-defined substrates holds promise to revolutionize fields dependent on nanoscale processes, such as catalysis, surface science, nanotechnology and modern day electronic applications. Herein, the adsorption configurations and surface sensitive interactions of two nonplanar regioisomer, trans - and cis -tetrakispentafluorophenylporphodilactone ( trans - and cis -H 2 F 20 TPPDL), molecules on (100) surfaces of Ag, Cu and Au were studied and investigated using high resolution scanning tunneling microscopy (STM), combined with ultrahigh vacuum tip-enhanced Raman spectroscopy (UHV-TERS). Depending on molecule–substrate interactions, similar “phenyl-up” configurations were observed for these molecules on Ag(100) and Au(100), while a “phenyl-flat” configuration was discovered on a Cu(100) surface. With the help of surface selection rules of TERS, we explain the spectral discrepancies recorded on the Ag and Cu substrate. Furthermore, the intermolecular interactions were addressed using STM analysis on these surfaces after the configurations were determined by TERS. This study sheds light on the distinct configurations of regioisomeric porphodilactone systems (at interfaces) for near-infrared (NIR) photosensitizers and molecular electronics in the near future.