In conclusion, this study successfully fabricated a bioactive nanoconjugate, ZnPcS4-AuNP-S-PEG5000-NH2-Anti-GCC mAb (BNC), based upon a PEGylated AuNPs, which was multi-functionalized with a fluorescent PDT metalated ZnPcS4 PS, and specific anti-GCC targeting mAbs, to overcome in vitro CRC PDD and PDT challenges. The gene discussed is GUCY2C; the disease is colorectal carcinoma.