Force field and quantum mechanical study of 3-aminopropyltriethoxy silane sorption on hydroxyl free yttria surface

[Display omitted] •Yttria: metal oxide useful in technological applications.•3-Aminopropyltriethoxy silane (APTES) is a suitable molecular system used as substrate for binding monoclonal antibodies to the surface of yttria nanoparticles.•Use of MD and DFT calculations to explain the interactions between yttria and APTES.•Chemisorption and physisorption of APTES on yttria surface.•Dative bond between nitrogen and yttrium atoms. In this paper, the development of Dreiding force field parameters to describe the structural features of yttria, has been done through a test and trial procedure. The parameters are used to study the interactions occurring between yttria’s surface with 3-aminopropyltriethoxy silane (APTES) molecular system, which has been used as a substrate to bind a monoclonal antibody (anti-CYFRA-21-1) to an adequately prepared surface of yttria nanoparticles. The work reveals that, on an eventual hydroxyl free metal-oxide surfaces the APTES molecules would adsorb on it with two layers. The first is a chemisorbed layer that covers the entire surface (surface-density of 2.10 × 10−6mol/m2) with a direct partially covalent dative bond between the nitrogen of the amine group of APTES and the yttrium atoms on the surface. The second is a physisorbed layer over the first, with a half the surface-density (c.a. 1.05 × 10−6mol/m2), where the APTES molecules amine groups are pointing outwards with respect to the surface. This makes possible the direct covalent bonding between the amine groups, of the outer adsorbed layer of APTES molecules, with the carboxylic group of the monoclonal anti-CYFRA-21-1 antibody. Quantum mechanical calculations confirmed the outcome of the force field study.