Engineering of IrO₂ nanofiber for surface enhanced Raman scattering

In this paper, we demonstrate the use of nano-engineered Ir/IrO₂ nanofibers (NFs) as substrates for surface-enhanced Raman scattering (SERS). We employed the electrospinning and annealing process to fabricate the IrO₂ nanofibers featuring of interconnected nanoparticles. The obtained IrO₂ NFs were subjected to reduction process as a function of time (5–180 min). IrO₂ NFs were fully converted to Ir metal after 120 min of reduction. The resulting structures were examined as SERS substrates using rhodamine 6G (R6G) molecule excited by 632.8 nm laser. A distinct Raman signal of R6G was identified and its intensity gradually increased as a function of the reduction time of IrO₂ NFs. UV/vis spectrum of Ir NFs showed increase of absorption at 632.8 nm, concluding that the enhanced Raman signal is due to the electromagnetic field enhancement at the Ir metal. This work is the first to report the nano-engineering of Ir/IrO₂ nanofibers for a SERS application.