Fig. 1. Experimental results. (a) UV-Vis diffuse reflectance spectra of golden pearls with different saturations; (b) reciprocal relationship between the intensity at 280 nm and 360 nm in the corresponding spectra

Fig. 2. Raman spectra of golden pearls at 405 nm excitation wavelength. (a)-(d) Raman spectra of GGC003 at different laser energies; (e)-(f) Raman spectra of GGC003 and GGC002 at 0.5% laser energy

Fig. 3. Microscopic optical images of golden pearls corresponding to different laser energies under 405 nm wavelength laser. (a) Laser energy is 0.05%; (b) laser energy is 0.5%; (c) laser energy is 10%; (d) laser energy is 50%; (e) (f) laser energy is 100%

Fig. 4. Experimental results. (a) (d) Raman spectra of golden pearls with different saturations under 532 nm excitation wavelength; Raman spectra of (b) GGC003 and (c) GGC002 under the same excitation wavelength and different laser energies

Fig. 5. Raman spectra of golden pearls with different saturations under 785 nm wavelength laser. (a) Laser energy is 5%; (b) laser energy is 50%