Abstract: A water-soluble semiconductor nanocrystal comprising semiconductor core and shell as well as a cap of one or more additional compounds comprising water-solubilization agents. The water-solubilization agent is chosen from the group consisting of: hydroxamates or derivatives of hydroxamic acid or a combination thereof, multidentate complexing agents or a combination thereof, a bilayer of a TOPO layer attached to the surface of the nanocrystal and an appropriate surfactant layer, a polymeric bead comprising carboxylic groups or amino groups or a combination thereof at the surface of the bead comprising one or more nanocrystal embedded within, a molecule of structural formula (R1)a—R2—{(R3)b(R4)c}d. Application to non-isotopic detection systems.