Comprehensive characterization of biocomposite surface based on the mesoporous silica and lysozyme molecules: Chemistry, morphology, topography, texture and micro-nanostructure

The results presented in this paper focus on a detailed analysis of surface composition, texture, morphology andmicro-nanostructure of mesocellular silica foam (MCF) covered by the lysozyme (LYS) molecules from aqueoussolutions at pH = 7.4. The physicochemical and structural properties of the LYS/MCF biocomposite werecharacterized by various techniques including attenuated total reflection (ATR) Fourier transform infraredspectroscopy (FT-IR), elemental analysis (CHN), X-ray photoelectron spectroscopy (XPS), diffuse reflectancespectroscopy (UV–Vis DRS), X-ray diffraction (XRD). Moreover, the morphology, micro-nanostructure, topo-graphy and elemental composition of biocomposite surface were determined using atomic force microscopy(AFM), optical profilometry (OP), high resolution transmission electron microscopy (HRTEM), energy dispersiveX-ray spectroscopy (EDX) and scanning electron microscopy with X-ray microanalysis (SEM/EDS). AFM, OP,TEM and SEM methods (with regard to morphology, topography, structure at a micro-nanometer level) de-monstrate that the surface of the support with immobilized protein is less rough, porous, wavy, sharp, and hencemore smooth,flat and uniform due to the proteins adsorbed on support surface. EDX and EDS demonstrated thehomogeneous distribution of protein molecules on silica surface. XRD confirmed that the lysozyme moleculeswere located on the support surface and inside the pores, and XPS revealed the specific interactions between thealbumin and silica.