Flower-like Cu nanoislands decorated onto the cicada wing as SERS substrates for the rapid detection of crystal violet

A low-cost, flexible, uniform and three-dimensional (3D) surface enhanced Raman scattering (SERS) substrate with abundant and regular hot spots was prepared by sputtering copper (Cu) nanoparticles on the cicada wings (CWs) with regular surface arrangement via magnetron sputtering. The formed Cu/CWs substrate proved to possess excellent SERS characters such as high sensitivity, eminent uniformity and repeatability. The results indicate that the optimal sputtering time was 30 min as detected by rhodamine 6G (R6G); the SERS limit of detection (LOD) for 4-aminothiophenol (4-ATP) was as low as 10(-7) M and the Raman enhancement factor (EF) was as large as 4 x 10(4) with the relative standard deviation (RSD) of the obtain characteristic feature less than 16%. More importantly, the crystal violet (CV) was also rapidly detected to have a LOD as low as 10(-7) M using the Cu/CWs substrate. In addition, the 3D finite-different time-domain (3D-FDTD) simulation indicated that the hot spots played a vital role in the electromagnetic (EM) enhancement and increasing the Raman signals intensity.