Nanochemistry and Biotechnology

Modeling of the nanoparticle interactions with biomolecules
Vlasova N.N., Markitan O.V.
Chuiko Institute of Surface Chemistry of the NAS of Ukraine. 
General Naumov Str.17, Kyiv-03164, Ukraine. 
E-mail: natalie.vlasova@gmail.com

At the interface between nanoparticles and biomolecules, organic and synthetic worlds merge into new science concerned with safe use of nanomaterials for their biomedical applications [1]. The interaction of oxide nanoparticles with biopolymers such as proteins, and nucleic acids can be modeled as complex formation reactions of monomer biomolecules with surface functional groups of solid. For this reason adsorption of nucleotides at the titanium oxide/aqueous solution interface was studied in terms of surface complexation theory [2]. This approach allows to quantitatively determine the stability of surface complex and to predict the types of the interaction between adsorbing molecules and active sites of solid. The charging of an oxide surface as a results of its interaction with protons of an aqueous solution give rise to an electrical double layer between electrolyte solution and the oxide. Surface complexation theory combines the law of mass action with the principals of the structure of electric double layer. The adsorption of nucleotides on the surface of nanocrystalline anatase (pHpzc = 6.5) in NaCl solution was investigated using potentiometric titrations and multi batch experiments over a wide range of pH and ionic strength. The Basic Stern model was applied to obtain quantitative equilibrium reaction constants. The nucleotides form stable electrostatic complexes on the anatase surface in which nucleotide anions are bound to protonated hydroxyl groups, TiOH. It can be assumed that nucleic acids in which bases are involved in the hydrogen bond formations, and the phosphate groups are free, interact with titania surface to form the same complexes as nucleotides.

1.	Gunnarsson S.B., Bernfur K., Mikkelsen A., Cedervall T. Analysis of nanoparticle biomolecule complexes // Nanoscale.-2018.-10.-P. 4246-4257. 
2.	Davis J.A., Kent D.B. Surface complexation modeling in aqueous geochemistry // Rev. Mineralog.-1990.-93.-P.177-260.