Polymer optical fiber SERS sensor with gold nanorods

A surface-enhanced Raman scattering sensor is developed by etching polymer optical fiber and coating with gold nanorods. The SERS sensing experiments are demonstrated with the analyte molecules of rhodamine 6G (R6G) at 514.5 nm laser excitation. The results show that a strong fiber Raman background scattering overwhelm the R6G molecule Raman signal in common optrod configuration, but a distinct R6G SERS spectrum with 9 order magnitude enhancement can be observed while directly focusing light on the probe. Further modeling indicates the enhancement is attributed to both nanorods local field and their coupling.