Figure 3

Si/SiO₂ QDs influence the secondary structure of BSA. (a) The IR spectra of BSA, BSA-QDs 1 h and QDs normalized to 1. The amide I and amide II bands from the spectra of BSA and BSA-QDs 1 h are labeled on the figure. The central frequency of BSA and BSA-QDs 1 h amide I bands are marked with dotted lines and the frequency shift is also labeled on the figure. (b) The amide I – amide II ratios calculated for the spectra of BSA and of BSA-QDs samples. (c) The deconvolution of amide I band of BSA-QDs 1 h was performed on the baseline corrected spectra passing through the ordinate at 1700 cm⁻¹ and 1600 cm⁻¹. The location of constituent bands was identified by analyzing the minima on their second derivatives spectra. The association of resulting Gaussians with secondary structures is given in the plot legend. (d) The secondary structure percents of BSA and BSA-QDs samples.