We computationally demonstrate enhanced local field amplification in tip-enhanced Raman spectroscopy (TERS) by integrating auxiliary plasmonic elements near a gold probe. The nanogap-dependent field enhancement between plas-monic spherical gold probe and sharp nanostructures, such as needles and sharp edges, are systematiclly investigated. The local field within the gap is shown to experience significant amplification. Here conical geometries yield the highest enhancement, among tested gold nanostructures on a dielectric substrate, followed by hemispheres and discs. Although discs provide weaker amplification, they enable broader analyte coverage, thereby improving Raman signal collection. Gap-dependent effects show that field amplification and nanometer-scale spatial localization occur even with the use of disk-shaped elements 100 times larger than the probe with a tip curvature radius of 60 nm. Our predic-tions indicate that hydrated samples may reduce field strength; however, this effect can be mitigated by maintaining an air gap. Finally, we propose that computational 2D field mapping, achieved by scanning the probe over a plasmonic disc, provides a practical framework for experimental validation. This approach lays the groundwork for optimizing TERS performance through a strategic design of plasmonic nanostructures.
Khrennikov et al. (Sun,) studied this question.