Fig. 2

FTIR spectra of linker-derived and peptide-derived peaks on titanium. Spectra of titanium treated with CDPA linker is shown as “Control” in Fig. 2. Five peptide-derived peaks of amide I (~1 650 cm−1) and amide II (~1 540 cm−1) were detected on the treated titanium surface with five peptides, indicating the immobilization of peptides on the titanium surface