Large-scale flexible metal-covered polymer nanopillar arrays as highly uniform and reproducible SERS substrates for trace analysis

While surface-enhanced Raman scattering (SERS) spectroscopy has been studied extensively due to its sensitivity to molecular vibration states, the fabrication of SERS substrates with homogeneous activity over a large area still remains difficult. Here, a facial fabrication of large-scale metal-covered polymer nanopillar arrays used as reliable SERS substrates was developed by nano-pouring process using porous alumina membranes. Our strategy integrates the advantages of low-cost production, high reproducibility and good biocompatibility because the flexible transparent polymer nanopillars are nondestructive to biomaterial surfaces. The as-prepared SERS substrates exhibit highly uniform Raman signals with low relative standard deviation values of 4% at 1169 cm −1 of CV and 8.1% at 1355 cm −1 of R6G, both with the concentration of 10 −5 M. The results also show that more than 95% intensity within the limits of the ±10% deviation of the average intensity of signals, indicating excellent stability of SERS signals. In addition, the mechanically flexible substrates can be attached to surfaces with complex morphologies and the good transparency makes the excitation and collection of signals from the backside of the substrates possible, showing great potential in analytical chemistry, food safety, medical diagnostics and other practical SERS detections.