The MBD1 protein was genetically modified by inserting two different foreign peptides to its N- and C-terminus: 1) histidine-rich peptides (H6) to be used as a gold ion (Au3+) chemisorption and gold nucleation site for on-site synthesis of the small AuNPs and 2) cancer cell receptor-binding peptides (EGFR-specific affibodies) to enhance cancer cell-targeting efficiency. Here, EGFR is linked to cancer.