Nitrogenous Bases in Relation to the Colloidal Silver Phase: Adsorption Kinetic, and Morphology Investigation

Abstract

The interaction between inorganic nanoparticles and biological molecules is of great importance in the field of biosystems and nanomaterials. Here, we report the adsorption process of a heterocyclic organic compound (nitrogenous base) on a microporous carbon (C) in the presence of a colloidal silver solution (AgNP solution) as an accompanying substance. Analysis of the potential colloid–biomolecule interaction as well as the subsequent phenomenon of changes in the morphology of the colloidal system in the presence of selected nucleotides was investigated. Adenosine nitrogenous base (Anb) was selected as a model molecule of the building block of DNA and RNA. The adsorption process of nucleotides from one- and two-component systems was monitored by cyclic UV-VIS measurements for obtaining time-dependent profiles and estimating the kinetic characteristics of uptake. We demonstrate the temperature-dependent course of the adsorption process with visible nucleotide-AgNP morphology determinants. The experimental adsorption kinetics were analyzed using selected theoretical models (intraparticle diffusion model, multiexponential equation, and many others). On the other hand, obtained Anb/C and Anb/AgNP/C composites were characterized by various techniques suitable for material surface and morphology characterization: high-resolution transmission electron microscopy (HR-TEM and TEM/EDX), N2 physisorption measurements, and thermal analysis (thermogravimetric analysis (TGA)/differential scanning calorimetry (DSC) experiments).