Features of the interaction of biomolecules with organic, inorganic or carbon structures ultimately determine the performance of any biosensor. This is due to the fact that it determines whether the functions inherent in the biological molecule, the use of which is the goal of creating biosensors, will be preserved during immobilization within the sensitive layer. That is why the study of hybrid materials is such an important part in the development of effective biosensors. Composite nanostructured layers of biological molecules with nanobodies are also of significant interest from the point of view of their implementation in gas sensors, so-called “bio-sniffers”. Their adsorption properties depend on surface morphology, particle size, packing, etc. Since there are many ways to create the surface organization of nanostructures, these materials open up wide opportunities for the development of new sensor coatings with desired adsorption properties.
In recent years, thanks to the advances in chemistry, there has been a significant increase in interest in carbon structures such as fullerene which is an allotropic modification of carbon, in which carbon atoms are connected by single and double bonds to form a closed mesh with fused rings. Of particular interest is the interaction of labile biomolecules with rigid frameworks of spherical fullerenes of the C60 type. In this work, we studied the features of such structures based on ovalbumin molecules. As an object of comparison, similar layers of ovalbumin, but deposited on a pre-deposited film of a classical organic semiconductor, copper phthalocyanine (CuPc), were studied. For research, QCM resonators with a resonant frequency of 10 MHz were used. Fullerene and CuPc films were obtained by thermal deposition in a vacuum. Proteins were deposited on the surface of C60 and CuPc by the drop method, i.e., protein molecules were bound to the surface due to physical adsorption. The effect of saturated vapors of alcohol, water, isobutyl alcohol, acetone, cyclohexane and benzene on the response of QCM sensors with two types of surface coatings was studied.
The results of a comparative analysis of the obtained data made it possible to confirm our earlier statement that biological molecules are capable of significantly changing their mechanical properties under the action of certain analytes. A necessary condition for this is the preservation of their labile structure and the possibility of interaction with the corresponding analytes, leading to a change in their spatial configuration. The reasons for this effect may be associated with the peculiarities of the influence of these compounds both on the structure of the protein and on the features of its connection with carbon nanocages.