Figure 4

(a) SERS spectra of 10⁻⁵ M R6G modified on the Ag nano-dendrite structure optical fibre substrate corresponding pre-processing substrate, after-processing substrate, and substrates stored for 700 h and 1000 h. The Raman signals intensities at 613.2 cm⁻¹, 1361.5 cm⁻¹, 1506.1 cm⁻¹ and 1650.7 cm⁻¹ decreased after processing surface of Ag nano-dendrite SERS optical fibre substrate and stored substrate time of 700 h, 1000 h (b).