With pronounced optical absorption and scattering, metal nanoparticles (MetNPs), such as gold (Au), silver (Ag), and copper (Cu), have found their way into a wide spectrum of applications, from biological to electrochemical. The effects that are the most important characteristics of these particles—the localized surface plasmon resonance (SPR) and high surface reactivity—are closely related to their physico-chemical features (size, shape, high percentage of unsaturated surface atoms, surface charge, medium, etc.), allowing researchers to design nanostructures tailored to specific biomedical applications based on a variety of biological processes occurring on the nanometer scale. The goal of this work is to present the abovementioned NPs with different sizes and shapes as free-standing or functionalized (by polymers—polyaniline and polypyrrole—or mesoporous silica) NPs, presenting an interesting and useful antimicrobial activity as one of their many beneficial features for application in biological systems. Besides NPs’ incorporation into polymers/silica protecting them from agglomeration and oxidation, their functionalization also improves their properties, making them, among other things, biocompatible and water-soluble materials that are easily synthesized with an excellent yield. Considering these antimicrobial biomaterials, additional attention should be paid to their cytotoxicity, environmental impact, and long-term stability, as well as potential microbial resistance development.

Acknowledgment: The research was funded by the Ministry of Science, Technological Development and Innovation of the Republic of Serbia, via direct financing of the Vinča Institute of Nuclear Sciences - National Institute of the Republic of Serbia (contract number: 451-03-66/2024-03/200017).