09:45 〜 10:00
[20a-E208-4] Silver Nanowire Based Tip-Enhanced Raman Scattering probe
キーワード：Tip-enhanced Raman scattering, Plasmonics, Silver nanowire
Tip-enhanced Raman scattering (TERS) microscopy is a unique analytical tool to provide complementary chemical and topographic information of surfaces with high spatial resolution at the nanometer scale. However, difficulties in reliably producing the necessary metalized scanning probe tips have limited its widespread utilization, particularly in the case of cantilever-based atomic force microscopy. We demonstrate the reproducible fabrication of cantilever-based high performance TERS probes for both topographic and Raman measurements, based on an approach that utilizes noble metal nanowires as the active TERS probe. The tips show 10 times higher TERS contrasts than the most typically used electrochemically-etched tips, and show reproducibility for TERS greater than 90%, far greater than found with standard methods. We show that TERS can be performed in tapping as well as contact AFM mode, with optical resolutions around or below 15 nm, and with a maximum resolution achieved in tapping-mode of 6 nm. To improve our probe’s performance, we utilize electrical cutting allowing strategically modification tip apex morphology. This doubles TERS signals on a gap-mode substrate compared to our standard nanowire tips while maintaining a high reproducibility and spatial resolution. More interestingly, the cut tips show 7 times higher signals on a dielectric substrate than our standard tips. Our works illustrate that superior TERS probes can be produced in a fast and cost-effective manner using simple wet-chemistry methods, leading to reliable and reproducible high-resolution and high-sensitivity TERS, and thus renders the technique applicable for a broad community.