particles whose electron density can couple with electromagnetic radiation of wavelengths that are far larger than the particle due to the nature of the dielectric-metal interface between the medium and the particles: unlike in a pure metal where there is a maximum limit on what size wavelength can be effectively coupled based on the material size.

(MNPs) a class of nanoparticle that can be manipulated using magnetic fields.

(UCNPs) nanoscale particles (diameter 1–100 nm) that exhibit photon upconversion.

The characterization of nanoparticles is a branch of nanometrology that deals with the characterization, or measurement, of the physical and chemical properties of nanoparticles.,.

Nanoparticles are classified as having at least one of its dimensions in the range of 1-100 nanometers (nm).