High-performance flexible surface-enhanced Raman scattering substrates fabricated by depositing Ag nanoislands on the dragonfly wing

•Dragonfly wing with irregular surface for template gets a high SERS performance.•The optimized structure of Ag on irregular DW was obtained by magnetron sputtering.•The prepared substrates are flexible, low-cost, large-scale and environment-friendly.•The limit of detection reaches 10−10M to 4-aminothiophenol.•Rapid and quantitative detection of crystal violet can be achieved by our substrates.