A
nanoparticle including an inorganic core comprising at least one
metal and / or at least one semi-conductor compound comprising at least one
metal includes a
coating or shell disposed over at least a portion of a surface of the core. The
coating can include one or more
layers. Each layer of the
coating can comprise a
metal and / or at least one
semiconductor compound. The
nanoparticle further includes a ligand attached to a surface of the coating. The ligand is represented by the formula: X-Sp-Z, wherein X represents, e.g., a primary amine group, a secondary amine group, a
urea, a
thiourea, an imidizole group, an
amide group, a phosphonic or arsonic
acid group, a phosphinic or arsinic
acid group, a
phosphate or
arsenate group, a
phosphine or
arsine oxide group; Sp represents a spacer group, such as a group capable of allowing a transfer of charge or an insulating group; and Z represents: (i) reactive group capable of communicating specific chemical properties to the
nanocrystal as well as provide specific chemical reactivity to the surface of the
nanocrystal, and / or (ii) a group that is cyclic, halogenated, or polar a-protic. In certain embodiments, at least two chemically distinct ligands are attached to an surface of the coating, wherein the at least two ligands (I and II) are represented by the formula: X-Sp-Z. In ligand (I) X represents a phosphonic, phosphinic, or phosphategroup and in ligand (II) X represents a primary or secondary amine, or an imidizole, or an
amide; In both ligands (I) and (II) Sp, which can be the same or different in the two compounds, represents a spacer group, such as a group capable of allowing a transfer of charge or an insulating group; Z, which can be the same or different in the two compounds, is a group chosen from among groups capable of communicating specific chemical properties to the
nanoparticle as well as provide specific chemical reactivity to the surface of the nanoparticle. In preferred embodiments, the nanoparticle includes a core comprising a
semiconductor material.