The CQDs were conjugated with a target molecule (Cetuximab) to facilitate CQDs-C225 labeling of HCC827 (lung cancer cell line, epidermal growth factor receptor (EGFR) over expression), H23 (lung cancer cell line, EGFR under expression), and HLF (normal lung cell line, EGFR under expression) cells. This evidence concerns the gene EGFR and lung cancer.