Patent ID: 7648843

Claim:
A colloidal semiconducting nanoparticle comprising an inorganic nanoparticle having at least one ligand attached thereto, the ligand comprising: a first module that contains two or more attaching groups; wherein each of the attaching groups comprises two sulfur atoms that are attached to an inorganic surface; wherein the attaching group has the structure and wherein s— represents the attachment of the sulfur atom to the inorganic surface; wherein the first module comprises: a number of alkylene moieties equal to the number of attaching groups, each alkylene moiety attached to one and only one of the attaching groups at a point other than at the sulfur atoms attached to the inorganic surface; a number of ester groups or methyl amide groups equal to the number of attaching groups, each ester group or methyl amide group attached to one and only one of the alkylene moieties; and a phenyl group attached to the ester groups or methyl amide groups at adjacent carbon atoms of the phenyl group; a second module that can impart water-solubility to the ligand and to the inorganic surface to which the ligand may be attached; wherein the second module is attached to the phenyl group; and a number of third modules equal to the number of second modules that contains a functional group; each third module attached to one and only one of the second modules.