竹状TiO₂ナノチューブ上への銀ナノ粒子のパルス電流電析による表面増強ラマン散乱基板の作製

In this work, we investigate the performance of surface-enhanced Raman scattering (SERS) substrates based on bamboo-like TiO₂ nanotubes (BTNTs) functionalized with silver nanoparticles (AgNPs) through pulsed-current electrodeposition (50 ms ON/250 ms OFF). The BTNT arrays, fabricated via alternating-voltage anodization, exhibit segmented morphologies that enhance nanoparticle anchoring and promote the dense generation of electromagnetic hotspots. Systematic optimization of deposition parameters revealed that 400 deposition cycles at a current density of 5 mA/cm² yielded the most favorable combination of nanoparticle distribution, structural morphology, and SERS activity. Under these conditions, the substrates achieved an analytical enhancement factor (AEF) of 1 × 10⁶ and enabled the experimental detection of methylene blue down to 1 × 10^-8 M (theoretical LoD 1 × 10^-9 M). This study demonstrates a cost-effective, scalable, and tunable fabrication strategy for highly active SERS platforms, offering significant potential for practical sensing applications.