Targeted imaging of gastric cancer in nude mice model by BRCAA1 monoclonal antibody-conjugated QDs. (a) Nude mouse model loaded with MGC803 cells and control mouse. (b) Targeted imaging of in vivo gastric cancer under dark visual field. (c) The fluorescence signal of in vivo gastric cancer (pseudocolor). (d) Colocalization image of bright field and fluorescence signal.