“…To characterize the molecules that can be absorbed on the surface of the biosynthesized NPs, the FTIR spectroscopy was used. 19 When Costa Silva et al 11 analyzed the samples of the synthesized AgNPs from the fungus D. flagrans in the FTIR, they reported two specific bands of proteins at 1,640 and 1,540 cm −1 identified as amide I and amide II, respectively, in addition to the band at 2,665 cm −1 , which is characteristic of the axial O−H deformation of carboxylic acid, and stretch bands at 730 cm −1 (CH 2 −S−S, possibly related to the cross-linking of disulfide between the amino acid cysteine), 1,000 cm −1 (C−O), 1,811 cm −1 (anhydrous C=O), 2,100 cm −1 (C≡O), 2,326 cm −1 , and at 2,665, 3,600, and 3,751 cm −1 (O−H).…”