Flexible Au-decorated cellulose acetate fibers for SERS detection of polycyclic aromatic hydrocarbons.

A variety of flexible surface-enhanced Raman scattering (SERS) substrates have been developed for Raman spectroscopic identification of environmental pollutants by virtue of their remarkable sensitivity, low cost and rapid sampling capacity. However, simultaneous achievement of high sensitivity, reliability, and reproducibility over large-area scales remains a significant challenge. Herein, an effective and facile strategy is proposed to fabricate flexible Au nanoisland-decorated cellulose acetate fibers (AuNI-CA) via electrospinning combined with magnetron sputtering. The flexible CA fibrous network was prepared with non-toxic solvents and acted as an ideal support for uniform Au deposition. A series of AuNI-CA substrates were obtained by precisely controlling the sputtering thickness. The optimized AuNI-CA-40 substrate exhibits outstanding SERS performance toward typical polycyclic aromatic hydrocarbons (PAHs) including phenanthrene and fluoranthene. It enables minimum detectable concentrations down to 10-8 M for phenanthrene and 10-9 M for fluoranthene, with enhancement factors of 1.30 × 105 and 5.82 × 107, respectively. Furthermore, the substrate demonstrates excellent signal uniformity with relative standard deviations of 5.56% for phenanthrene and 6.42% for fluoranthene. This work provides a promising and reliable platform for the trace detection of PAHs in environmental applications.