Scheme of synthesis of CdSe/ZnS QDs, amphiphilic polymer, and coating process and their biological applications. (a) Typical synthesis of CdSe/ZnS QDs in high temperature and cosolvent. (b) Synthesis of amphiphilic polymer: cross-linking PAA and OA by EDC. (c) Phase transfer of QDs from hydrophobic phase to hydrophilic phase by stirring and sonication. (d) Reaction scheme for coupling targeting antibody to PQDs by EDC. (e) Single molecule labeling and cell imaging with PQDs in vitro. (f) General labeled cancer cell with PQDs for imaging in vitro and in vivo.