Rapid development of nanotechnology in processes of metal nanoparticle immobilization on solid surfaces, especially polymeric ones, requires the study of particular issues within these complex approaches. Numerous studies have been published on laser light mediated manipulation with single metal nanoparticles in water environment and even laser assisted immobilization of such particles on polymeric substrate, however, not much has been reported on fundamentals of underwater laser processing of polymer itself, especially regarding to resulting surface morphology and chemistry. In this work, we study surface morphology (atomic force microscopy (AFM)) and chemistry (angle-resolved X-ray photoelectron spectroscopy (ARXPS) and inductively coupled plasma-mass spectroscopy (ICP-MS)) of polyethylene terephthalate (PET) after underwater laser treatment in broad scale of applied laser fluencies and operating voltages. Due to typical dependence of laser efficiency on operating voltage, induced nanostructures on PET exhibited a noticeable symmetry spread out around the maxima of laser efficiency for low laser fluencies. The study of surface chemistry revealed that at high laser fluencies, photochemical decomposition of macromolecular polymer structure took place, resulting in rapid material ablation and in balanced chemical composition of the surface throughout the studied profile. Enrichment of the water bath by the low-molecular polymer degradation products proves that ablation mechanism is the governing process of surface nanostructure formation in underwater laser processing.

Noble metals in their diverse nanoforms bring revolution to many fields of science and technology, as they provide unique properties over their bulk counterparts. Thanks to these completely unprecedented properties, commercial sphere pressure is growing to use them in everyday life. Unfortunately, one of the issues that are subject to dramatic changes is the reactivity of these structures. This may have often fatal consequences to the living organisms. Due to the fact that the mechanism of action of metal nanostructures on living organisms is not yet fully elucidated even in the case of the most studied noble metals such as gold and silver, it is necessary to continue intensively in their research, characterization and categorization. The main prerequisite for the undistorted study of interactions of nanostructures with living organisms is the use of suitable methods of their preparation. Within this context, this chapter attempts to summarize current knowledge form the field of synthesis of metal nanoparticles, layers, wires, and other nanostructures, especially regarding novel techniques of their preparation and extend them by our own results in this area, in the context of their biological properties. More specifically, antibacterial efficacy and potential cytotoxicity of those structures are thoroughly addressed.