Electrodeposition and transfer of silver micro-kohlrabies for stretchable surface-enhanced Raman scattering.

Abstract

Stretchable surface-enhanced Raman scattering (SERS) substrates are pivotal for real-time chemical sensing on deformable surfaces but face challenges in maintaining sensitivity under mechanical strain. Here, we introduce a two-step electrodeposition and double-embedded transfer method to fabricate silver micro-kohlrabies (Ag MKs) on stretchable substrates. Ag microspheres are first electrodeposited on ITO/glass, followed by the growth of Ag nanodendrites at optimized voltage (1.3 V) and time (5 min), forming hierarchical micro-nano structures with abundant electromagnetic hotspots. A double-embedded transfer technique involving polyvinyl alcohol (PVA) and polydimethylsiloxane (PDMS) ensures robust integration of Ag MKs onto elastomeric substrates while preserving hotspot accessibility. The resulting substrate demonstrates high sensitivity with an enhancement factor of ~10⁷, uniformity, mechanical durability (50 stretch cycles at 50% strain), and stability (30-day storage). Practical application in thiram detection achieves a detection limit of 10^-8 M, highlighting its potential for on-site pesticide monitoring. This work advances stretchable SERS platforms by combining tunable nanostructure fabrication with reliable mechanical performance.