Studies on molecular structure of biocompatible polymers by vibrational spectroscopy [24] ATR-IR studied of protein adsorption onto biocompatible polymer

Time-resolved IR spectra of protein adsorption process onto a polymer surface from buffer solution have been investigated by using an original in-situ attenuated total reflection infrared (ATR-IR) cell (Figure 1). The signal from adsorbed protein was selectively observed, i.e., that from natural protein in solution was not detected by the method. Figure 2 shows that the amide I bands (1700-1600cm^-1) and the OD stretching band (2150-2200cm^-1) regions of time-resolved spectra. Increase of amide I band and decrease of OD stretching band with time were observed (Figure 3). This result indicates that water molecules existing on the surface were desorbed by protein adsorption onto polymer surface. Protein adsorption from the aspect of water molecules will be discussed in detail.