Fabrication of transparent SERS platform via interface self-assembly of gold nanorods and gel trapping technique for on-site real time detection

A transparent SERS platform was fabricated via the gel-trapping method coupled with a liquid/liquid interface self-assembly technique. We employed gold nanorods as the building blocks for interface self-assembly because of their strong localized surface plasmons upon excitation by infrared radiation. Based on a "top cover" configuration, this transparent SERS platform endows high signal reproducibility for directly detecting liquid samples by confining the sample droplet into a regular shape. The Au NR PDMS platform was able to directly detect crystal violet in aqueous solutions down to 10 ppb level with high enhancement factor (0.87 × 10⁵) and signal uniformity (RSD = 3.9%). Furthermore, SERS-based anti-fungal agent detection on a fish scale was demonstrated by simply covering the fish scale with a tailored GNRs PDMS film. The experimental results clearly show that the Au NR PDMS SERS platform has great potential for on-site real time detection of contaminants in water as well as on curved surfaces.