Zinc-based nanoclusters, methods for obtaining same and uses thereof for combatting zinc deficiencies

Zinc-based nanoclusters, comprising a zinc-based metal core covered over its entire surface with a mixed layer comprising histidine (His), acetate ions (Ac), and ascorbate ions (Asc), said metal core being composed of zinc (Zn) or a mixture of zinc and selenium (ZnSe), the zinc in said mixture ranging from 80 to 99.99% and the selenium in said mixture ranging from 0.01 to 20%, the percentages being percentages by weight relative to the total weight of the mixture,

• wherein the zinc-based nanoclusters:
• have a spherical shape,
• have a hydrodynamic diameter ranging from 0.6 to 2.0 nm,
• have a metal core diameter ranging from 0.5 to 1.5 nm,
• exhibit a stability duration ranging from 5 to 20 weeks when the nanoclusters are in liquid form and are stored at a temperature of 4° C.,
• exhibit a stability duration of at least 12 months, and preferably from 12 to 18 months, when the nanoclusters are in dry form and are stored at a temperature of 4° C. and under nitrogen, and
• 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,
• wherein the zinc-based nanoclusters having a metal core composed of Zn are referred to as having a formula ZnNC@HisAcAsc, and the zinc-based nanoclusters having a metal core composed of the ZnSe referred to as having a formula ZnSeNC@HisAcAsc.