RETRACTED: Thermal investigation of montmorillonite/BSA by Fourier Transform InfraRed Spectroscopy measurements

Abstract

<abstract> <p>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 allows to highlight the importance of montmorillonite as thermal bio-protector: this is also evidenced by the theory widely discussed in the following introduction regarding the birth of the first life forms on earth in montmorillonite clay, in which the protective role of the montmorillonite interlayer space is also highlighted. 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.</p> </abstract>

Metal-Modified Montmorillonite as Plasmonic Microstructure for Direct Protein Detection

“…The low enhancing efficiency of Al_MMT treated with Trp can be explained by the low absorption of Trp of MMT due to the counterbalance of either positive (-NH 2 ) and negative (-COOH) groups in the aminoacidic structure. On the contrary, different studies showed the prompt absorption of BSA at the surface or the edges of MMT by electrostatic and/or chemical interaction [42,43]. Noticeably, while the fluorescent signal measured for Trp was reproducible between different tests (small standard deviation) both in water and with Al_MMT (Figure 7A), the reproducibility between measurements was observed only in water in the case of BSA.…”