## 1 Introduction  
The importance of nanosized metal clusters is well known and appreciated in various sectors of science and modern technology. Due to the rapid development of nanotechnology, their products are becoming increasingly common in almost all areas of our life. Noble metal nanoparticles are meaningful components in a wide area of applications, technological solutions, and future developments due to their physical and chemical properties correlated with size and morphology [1; 2; 3]. Based on nanoscale elements, the nanocomposite materials, as well as other hybrid structures, are designed and produced on a fairly large scale. The idea of immobilization of the nanoparticles on solid surfaces may lead to their stabilization and avoid uncontrolled release to nature due to the increasing problem of their safety on the health of living organisms and the natural environment [4; 5]. These concerns are associated with the potential impact of nanosized particles on living organisms and cells, and thereby on the building blocks of genetic information, their replication, and structural construction [6; 7; 8]. Interactions between DNA, proteins, and many other types of bioactive molecules have been an important area of research due to the possible interaction of silver nanoparticles with different binding sites in the DNA chain, including nucleobases, sugars, and phosphates [9]. Based on this, heterocyclic molecules containing phosphorus and nitrogen elements are important due to their applicability in the regulation of enzymatic activity and interaction with biological systems [10]. A comprehensive approach to the issue of phosphorus nitrogen heterocycles and their importance is presented in the literature [11]. It is worth paying attention to the modification of the surface of solid carriers in the form of metal oxides with organic phosphonic acid derivatives, which are an excellent example of the construction of organic-inorganic hybrid materials [12]. Among them, heterocycle systems (with phosphorus and nitrogen elements) are valuable for their importance in biological systems [13; 14]. For example, an adenosine molecule can be presented, whose derivatives, i.e., (i) deoxyadenosine is a building block of DNA, (ii) adenosine mono-, di-, or triphosphate (AMP/ADP/ATP) act as energy carriers [15], and (iii) cyclic adenosine monophosphate (cAMP) is pervasive in signal transmission [16]. The role of phosphorus in the living cell comes with a few features. This element is part of cellular membranes as building phospholipids, it is a major element of DNA and RNA nucleic acids [17], and it is a key nutrient involved in the transfer of energy and the synthesis of several cellular components (ATP and NADPH), involved also in the photosynthesis process. The adsorption of heterocyclic compounds seems to be very important in the context of the functioning of biological systems and chemical processes. In the first case, the adsorption of heterocyclic compounds in the biological system can be represented as a surfactant-polyelectrolyte assembly. Interactions between polyelectrolytes and surfactants can be studied in the bulk phase and on the solid surface. The method used to determine the interaction is the measurement of the surface tension curve of the surfactant in the presence and absence of the polyelectrolyte [18; 19; 20]. On the other hand, possible mechanisms of interaction may include noncovalent interaction between the negative charge of biomolecules and metal ions. One of the examples is the interaction between the negative charge of the phosphate backbone. Silver nanoparticles exhibit a high affinity to sulfur and nitrogen atoms and their derivatives [21]. The affinity phenomena of silver nanoparticles towards sulfur and nitrogen atoms was investigated in detail in the literature [22]. The aggregation effect of the particles, visible change of colors, and change in the surface plasmon resonance characteristics [23] indicate the possible interaction between metal clusters and biomolecules.