A method for covalent attachment of peptides to luminescent quantum dots or other inorganic nanoparticles. The first step in the method involves functionalizing at least a portion of a surface of the quantum dot or nanoparticle with one or more materials having at least one reactive functional group therein. Subsequently, a peptide having a reactive functional group is reacted with at least some of the quantum dot or nanoparticle reactive functional groups to covalently bond at least some of the peptide to the quantum dots or nanoparticles. Modifications of the basic method are disclosed which provide methods allowing customized fabrication of quantum dots having a variety of different functional properties and combinations of functional properties. Also disclosed are quantum dots and nanoparticles made by the methods of the present invention.