Fig. 3.

Examples of UV–vis spectra of C₆₀ dispersed in aqueous solutions of: (A) BSA; (B) lysozyme; (C) hydroxypropyl-β-cyclodextrin; (D) natural frog foam nest fluid. Note that the BSA and lysozyme samples are unstable and precipitate irreversibly shortly after formation. This is illustrated in panel (A), where line (i) is the spectrum of the BSA-C₆₀ dispersion after 1 day mixing, together with the spectrum of the BSA solution alone (ii) showing the typical 280 nm protein absorbance band. Both these bands disappear after spontaneous precipitation (iii) a few days later.