The core of such particles usually consists of a semiconductor or ferromagnetic / superparamagnetic phase, and the shell is another semiconductor phase, SiO₂ or a biocompatible polymer. The literature also refers to double-layer fluorescent particles based on fluorides and some chalcogenides of rare earth elements (scandium, yttrium, lanthanum and the lanthanides).

The main advantage of multilayered particles is their polyfunctionality, which is a result of core and shell division, and the optimisation of the target physical and chemical properties of the core material. Creating core-shell particles may be due to the need to isolate the core from the environment, fix special groups and reagents for target drug delivery at the outer layer, intensify energy absorption and emission by luminescent particles, etc.

The main difference between the particles of this type and the Janus particles (see Janus particles) is the morphological features of their components’ mutual arrangement, where there is only one of them on the surface of the particle.