(a)
(b)
(c)
Figure 4: Fluorescence spectra for HSA in phosphate buffer with pH 7.40 at 25°C. (a) a → d represents the fluorescence spectra of the beginning of reaction for HSA, HSA and MTO, HSA and CHP NPs, and HSA and MTO-CHP NPs, respectively. (b) a → c represents the fluorescence spectra for HSA and MTO, HSA and CHP NPs, and HSA and MTO-CHP NPs, respectively, after the reaction was completed at 15 h. (c) Change in maximum fluorescence intensity as a function of time combined with MTO (a), CHP NPs (b), and MTO-CHP NPs (c).