Highly Durable and Reusable 3D Copper Foam-Based SERS Substrate with CuO-Ag Nanorods for Ultrasensitive Measurements of Rhodamine-6G and Human Urine

A three-dimensional structure has garnered significant interest as a potential material for ultradurable and recyclable surface-enhanced Raman scattering (SERS). Leveraging the superior chemical and physical stability, together with the extensive surface area of the 3D copper foam (CF), CuO nanorods were grown within the CF to increase the surface-active area and photocatalytic properties. CF@CuO-Ag was effectively fabricated to boost the SERS performance through the deposition of Ag nanostructures onto the surfaces of CuO nanorods. The CF@CuO-Ag substrate exhibited exceptional sensitivity, detecting Rhodamine-6G (R6G) at concentrations as low as 10 ρM and successfully analyzing actual human urine samples. The substrate demonstrated remarkable recyclability, maintaining SERS efficiency after three cycles of UV cleaning for both R6G and urine samples. Furthermore, it has shown exceptional physical stability, enduring abrasion from sandpaper, and preserved surface integrity after 25 days of exposure to air. The remarkable sensitivity and stability of the CF@CuO-Ag substrate render it a promising choice for the rapid on-site detection of fungicides and antibiotics in soil and future disease monitoring.