Nanoparticles (NPs) are particles in the range of 1-100 nanometers (nm) in size with a surrounding capping agent or otherwise known as stabilizer, surface ligands or passivating agent. The capping agent is an integral part of nanoscale matter, fundamentally affecting all of NPs’ properties, while it could be of various chemical compounds i.e. ions, inorganic and organic molecules endowing to the NP the appropriate surface chemistry endowing colloidal stability as well as proper surface functionalities for interaction with other substances. In nanotechnology, a particle is defined as a small object that behaves as a whole unit with respect to its transport and properties, while the type of NP element as a function of the size & morphological characteristics could give a great variety of different properties (LSPR, SERS, catalytic, sensing, electrical and thermal conductivity, etc.)
