Abstract: Zinc-based nanoclusters having: a zinc-based metal core covered over its entire surface with a mixed layer including histidine, acetate ions, and ascorbate ions, the metal core composed of zinc or a mixture of 80 to 99.99 wt % zinc and 0.01 to 20 wt % selenium; a spherical shape; a hydrodynamic diameter of 0.6 to 2.0 nm; a metal core diameter of 0.5 to 1.5 nm; a stability of 5 to 20 weeks in liquid form stored at 4° C.; a stability of at least 12 months in dry form stored at 4° C. under nitrogen; a shoulder in the UV-visible spectrum at 300±15 nm and a fluorescence spectrum with excitation wavelengths of 364±15 nm and emission wavelengths of 415±15 nm. Also, a method of preparing the zinc-based nanoclusters and their use for combating zinc deficiencies or zinc and selenium deficiencies.

Abstract: Iron nanoclusters that: are covered on their surface with a mixed layer comprising histidine (His), acetate ions (Ac), and ascorbate ions (Asc), have a spherical shape, have a hydrodynamic diameter ranging from 0.6 to 2.0 nm, have metal core diameter ranging from 0.5 to 1.5 nm, exhibit a stability duration ranging from 5 to 20 weeks in liquid form stored at 4° C., exhibit a stability of at least 12 months in dry form stored at 4° C. under nitrogen, exhibit spectrophotometric properties, with a shoulder in the UV-Visible spectrum at 300±15 nm and a fluorescence spectrum with excitation wavelengths of 364±15 nm and emission wavelengths of 415±15 nm. Also, a method of preparing the iron nanoclusters, and their uses for combating iron deficiencies.

Abstract: Copper nanoclusters designated by the formula “CuNC@HisAc” or “CuNC@HisAcAsc”, wherein the copper nanoclusters: are covered on the surface thereof by a mixed layer including histidine (His), acetate ions (Ac) and possibly ascorbate ions (Asc); have a spherical shape; have a hydrodynamical diameter of 0.6-2.0 nm; have a metallic core with a diameter of 0.5-1.5 nm; have a temporal stability of 5-12 weeks in solution; have a temporal stability of at least 12 months in dried form; and have spectrophotometric properties, with a shoulder in the UV-Visible spectrum at 325±10 nm and a fluorescence spectrum with excitation wavelengths of 365-395 nm and emission wavelengths of 445-475 nm. Also, a method for preparation of the copper nanoclusters, and the use of the copper nanoclusters in a method treatment of pathologies related to a copper deficit, and in particular Menkes syndrome.