We described a facile method for preparing CdSe/CdS/ZnS core/shell/shell nanocrystals from air-stable single source precursors. The single source precursors of cadmium ethylxanthate and zinc ethylxanthate were used to form CdS and ZnS shell layers in octadecene. An efficient modification of CdSe/CdS/ZnS nanocrystals was subsequently performed to obtain hydrophilic nanocrystal fluorophores with good stability in a pH range of 1.6-10.