Thermal investigation of montmorillonite/BSA by fourier transform infrared spectroscopy measurements<xref ref-type="fn" rid="fn1"><sup>1</sup></xref>

This paper reports the analysis of the intramolecular OH stretching band obtained by Fourier Transform Infrared (FTIR) spectroscopy measurements. In order to characterize the effect of montmorillonite on the properties of Bovine Serum Albumin (BSA) the two-state model is adopted for the analysis of the OH stretching band. We assume that the OH stretching can be divided into two different states of inter-molecular bonding. The results of this experimental work confirm that the montmorillonite leads to a stabilization of the BSA structure. Also, the analysis of the spectra temperature dependence shows a montmorillonite-induced higher thermal stability of the BSA in respect to pristine BSA. Thus, this paper highlights the effectiveness of montmorillonite as thermal bio-protector. A FTIR analysis was carried out to investigate the interaction of Montmorillonite with BSA. Two different approaches, i.e. Spectral Distance and Wavelet analyses, constitute two effective and innovative approaches for the characterization of the thermal properties of pristine BSA and of BSA in the presence of Montmorillonite. The results allowed us to consider as BSA in the presence of Montmorillonite has a lower spectral sensitivity when the temperature changes and, therefore, the role of Montmorillonite as a thermal bio-protector is motivated.