| dc.description.abstract | This work aims to investigate the adsorption of bovine serum albumin (BSA) on
different surfaces, namely silicon, germanium, and porous titanium dioxide (TiO2), in order
to understand the mechanisms governing protein–surface interactions and to evaluate the
effect of porous structures on adsorption behavior.
In the theoretical part, the fundamental concepts related to proteins, porous surfaces, and the
adsorption phenomenon were reviewed, with particular emphasis on titanium dioxide because
of its unique physical, chemical, and biological properties. Fourier Transform Infrared
Spectroscopy in Attenuated Total Reflection mode (FTIR-ATR) was also presented as an
effective technique for monitoring the adsorption process and analyzing the structural
changes occurring in proteins during their interaction with solid surfaces. In addition,
classical kinetic models commonly used to describe adsorption kinetics were examined,
including the Pseudo-First-Order (PFO), Pseudo-Second-Order (PSO), and Intraparticle
Diffusion models.
In the experimental part, porous titanium dioxide thin films were prepared on germanium
substrates using the drop-casting technique. Adsorption experiments of BSA were then
carried out on silicon, germanium, and porous titanium dioxide surfaces. The obtained results
were analyzed using both classical kinetic models and a proposed Three-State Kinetic Model
developed to describe the complex and multistep nature of protein adsorption.
The results showed that the adsorption process is strongly influenced by the nature of the
surface and that classical kinetic models are not sufficient to accurately describe all stages of
the process. In contrast, the Three-State Model provided the best agreement with the
experimental data for all investigated surfaces, confirming that protein adsorption proceeds
through several successive stages involving molecular transport in the bulk solution, surface
adsorption, molecular rearrangement, and diffusion into the pores.
The study also demonstrated that porous titanium dioxide exhibits a higher adsorption
capacity than non-porous surfaces such as silicon and germanium. This behavior is attributed
to the contribution of the internal pores, which provide additional sites for protein retention
and facilitate diffusion within the porous structure. Overall, the proposed model offers a more
accurate and realistic description of protein adsorption kinetics and represents an important
step toward a better understanding of biological interactions at solid surfaces, thereby
contributing to the development of more effective medical and technological applications. | en_US |