Fig. 1. Schematic of Raman detection system

Fig. 2. (a) Morphology of Ag nano-film on carbon electrode; (b) test results of repeatability and stability of SERS electrode

Fig. 3. Raman spectra of sulfamerazine solutions with different pH values

Fig. 4. Relationship between Raman spectral intensity and pH value of sulfamethazine solution

Fig. 5. Raman spectra of sulfamerazine solutions under different working voltages

Fig. 6. Relationship between Raman spectral intensity and working voltage of sulfamethazine solution

Fig. 7. Raman spectra of sulfamerazine solutions under different accumulation time

Fig. 8. Relationship between Raman spectral intensity and accumulation time of sulfamethazine solution

Fig. 9. Raman spectra of sulfamerazine solutions with different concentrations

Fig. 10. Relationship between Raman spectral intensity and concentration of sulfamethazine solution

Fig. 11. Raman spectra of amikacin solutions with different concentrations

Fig. 12. Relationship between Raman spectral intensity and concentration of amikacin solution

Fig. 13. Raman spectra of enrofloxacin solutions with different concentrations

Fig. 14. Relationship between Raman spectral intensity and concentration of enrofloxacin solution

Fig. 15. Raman spectra of ciprofloxacin solutions with different concentrations

Fig. 16. Relationship between Raman spectral intensity and concentration of ciprofloxacin solution