The study of the interaction mechanism between bovine serum albumin and single-walled carbon nanotubes depending on their diameter and concentration in solid nanocomposites by vibrational spectroscopy

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 227; p. 117682
• Main Authors: Gerasimenko, Alexander Yu, Ten, Galina N., Ryabkin, Dmitry I., Shcherbakova, Natalia E., Morozova, Elena A., Ichkitidze, Levan P.
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 15.02.2020
• Subjects: Amino acid; Bovine serum albumin (BSA); Cells viability; Covalent and hydrophobic interactions; FTIR and Raman spectroscopy; Nanocomposite; Single-walled carbon nanotubes (SWCNT); Cells viability; Amino acid; Bovine serum albumin (BSA); Nanocomposite; Covalent and hydrophobic interactions; Single-walled carbon nanotubes (SWCNT); FTIR and Raman spectroscopy
• ISSN: 1386-1425; 1873-3557
• DOI: 10.1016/j.saa.2019.117682

The results of the study of composites based on bovine serum albumin (BSA) and single-walled carbon nanotubes (SWCNT) are presented. Nanocomposites were created by evaporation of the water-albumin dispersion with nanotubes using diode laser with temperature control. Two types of nanotubes were used. SWCNT I were synthesized using the electric arc method, SWCNT II were synthesized using the gas phase method. SWCNT I had a diameter and length less than SWCNT II. The mechanism of interaction between BSA and SWCNT in solid nanocomposites is considered. An experimental and theoretical studies of the interaction between aspartic (Asp) and glutamic (Glu) amino acids located on the outer surface of BSA and nanotubes using of vibrational spectroscopy (Fourier-transform infrared (FTIR) and Raman spectroscopy) was carried out. The possibility of nanotubes functionalization by oxygen atoms of negative amino acid residues Asp and Glu, which are on the outer surface of BSA, is shown by molecular modeling. The formation of covalent bonds between BSA and SWCNT in nanocomposites with different concentrations of nanotubes (0.01, 0.1 and 1 g/l) was confirmed by vibrational spectra. The covalent interaction between BSA with SWCNT under the laser irradiation leads to the conformational changes in the secondary and tertiary structures of albumin. This is confirmed by a significant decrease in the intensity of the absorption bands in the high-frequency region. The calculation of the vibrational spectra of the three Glycine:Glycine, Glutamic acid:Threonine and Aspartic acid:Lysine complexes, which take into account hydrogen, ion-dipole and ion-ion bonds, showed that a disturbance in the intermolecular interaction between amino acid residues led to significant decrease in the intensity of absorption bands in the region of stretching vibrations bonds OH and NH. From the Raman spectra, it was found that a significant number of defects in SWCNT is caused by the covalent attachment of oxygen atoms to the graphene surface of nanotubes. An increase in the diameter of nanotubes (4 nm) has practically no effect on the absorption spectrum of nanocomposite, while measuring the concentration of SWCNT affects the FTIR spectra. This confirmed the hydrophobic interaction between BSA and SWCNT. Thus, it was shown that BSA solid nanocomposites with CNTs can interact either with the help of hydrophobic forces or with the formation of covalent bonds, which depends on the diameter of the used nanotubes. The viability of connective fibroblast tissue cells on nanocomposites with both types of SWCNT was demonstrated. It was found that nanocomposites based on SWCNT I provide slightly better compatibility of their structure with fibroblasts. It allows to achieve better cell adhesion to the nanocomposite surface. These criteria make extensive use of scaffold nanocomposites in biomedicine, depending on the requirements for their quality and application. [Display omitted] •We created BSA nanocomposites with different sizes and concentrations of SWCNT by the laser method.•The mechanism of interaction between BSA and SWCNT in nanocomposites has been investigated by FTIR and Raman spectroscopy.•The possibility of SWCNT functionalization by oxygen atoms of amino acid Asp and Glu was shown by molecular modeling.•The covalent interaction between BSA and SWCNT leads to the changes in the secondary and tertiary structures of albumin.•Significant number of SWCNT defects is caused by the covalent attachment of oxygen atoms to the graphene surface.