Fig. 4

Raman spectra of all synthesized nanoparticles MSN, PLGA and pure chlorhexidine powder are shown (a) When using excitation wavelength of 532 nm laser, the synthesized mesoporous silica powder (red spectrum) shows a Raman spectrum having prominent signals at 638, 802 and 1300 cm⁻¹. The band around 1300 is attributed to the lactic units. The peaks between 400 to 1350 cm⁻¹ are assigned to pure CHX powder. CHX-loaded/MSN exhibited a characteristic peak of Raman scattering at 638, 802, 1011, 1035, 1067 and 1300 cm⁻¹. b The Raman spectrum at 1446 cm⁻¹ for CHX-loaded/MSN-PLGA is suggestive of anti-symmetric vibration from the lactic unit corresponded as CH₂ deformation which is confined to a lower intensity in CHX-loaded/MSN groups. The assignments at 1040 and 1127 cm⁻¹ corresponds to CH₃ rocking and CH₂ wagging