(A) UV-vis spectra and (B) FTIR of (a) OMCAPs, (b) rBSA-FA, (c) OMCAPs@rBSA-FA, (d) free IR780 and (e) OMCAPs@rBSA-FA@IR780. (C) UV-vis spectra of TMB in various reaction systems: (a) TMB + H2O2 (control), (b) TMB + H2O2 + OMCAPs and (c) TMB + H2O2 + OMCAPs@rBSA-FA in NaAc buffer (pH 6.0) after 10 min reaction. Inset: Time-dependent absorbance changes at 652 nm of TMB + H2O2 + OMCAPs@rBSA-FA with various pH conditions. The concentrations of TMB, H2O2, OMCAPs and OMCAPs@rBSA-FA were 0.416 mM, 100 μM, 10 μg/mL and 10 μg/mL, respectively. (D) The determination of ·OH by recording fluorescence spectra of H2O2 + TA (control), H2O2 + OMCAPs + TA and H2O2 + OMCAPs@rBSA-FA + TA.