Surface-enhanced Raman spectroscopy based on Silver nano-dendrites on microsphere end-shape optical fibre for pesticide residue detection

In this paper, we present a novel type of surface-enhanced Raman spectroscopy (SERS) substrates using the surface of microsphere end-shape optical fibre coated silver nanodendrites fabricated by laser-assisted photochemical method, which can one-timely synthesis and deposit nano-silver on the surface of microsphere. The morphology and chemical composition of SERS microsphere-shape optical fibre substrates characterized by field emission scanning electron microscope (FE-SEM) and energy dispersive X-ray (EDX), respectively, show that the Ag nanodendrites coated on the surface of microspherical end-shape have excellent reproducibility and stability in the morphology and structures. The SERS-activity of microsphere end-shape optical fibre substrates has been tested by ultralow concentration of Rhodamine 6 G and detected Dimethoate pesticide in the low-concentration range of 0.005 ppm–4 ppm with Limit of Detection (LOD) of 0.002 ppm. This study indicated that SERS substrate based on microsphere end-shape optical fibre coupled with silver nanodendrites is a large potential tool for applications in high sensitive chemo-sensing technique.