Improved versatile SERS spheroid end-facet optical fiber substrate based on silver nano-dendrites directly planted with gold nanoparticles using dual-laser assisted for pesticides detection

In this work, the novel versatile surface-enhanced Raman scattering (SERS) spheroid end-facet optical fiber substrate based on directly planting Au nanoparticles (AuNPs) on the surface of Ag nano-dendrites (AgNDs) via an in-situ growth method with dual-laser assisted was successfully fabricated. The enhancement factor (EF) for Rhodamine 6G (R6G) was calculated to be 2.54 x 10(7) and reached the highest value compared with other AuNPs and AgNDs SERS substrates. 40-day-duration stability tests showed that the Raman intensity of R6G on AuNPs/AgNDs SERS substrate reduced only by 11.16% and improved more stable than the AgNDs SERS substrate of 44.07%. Moreover, due to high SERS performance of AgNDs nanostructures and the chemical stability of AuNPs, the AuNPs/AgNDs SERS substrates were employed for rapid detection of cypermethrin and fenthion with limit of detection (LOD) of 2.87 x 10(-4) ppm and 1.7 x 10(-4) ppm, respectively. The AuNPs/AgNDs SERS spheroid end-facet optical fiber platform possesses high sensitivity, good uniformity and outstanding temporal stability thus can be used for realization of integrated portable pesticide detection devices.