Gold nanoparticles (AuNPs) have garnered significant attention for their potential applications in cancer therapy. This study developed a novel formulation of AuNPs, named AuX2R, utilizing surface modification techniques to enhance biocompatibility and targeting capabilities for cancer treatment. The innovation of AuX2R lies in its simultaneous surface modification with polyethylene glycol (PEG) and lipidized peptides (pepducin), aimed at improving stability and cancer cell specificity. The study compared the stability of three different formulations of AuNPs in various solutions, indicating that PEGylation significantly increased nanoparticle stability, while the incorporation of pepducin enhanced their internalization and targeting towards cancer cells. This research not only provided a detailed analysis of the physicochemical properties and stability of the novel AuNPs but also investigated their internalization in prostate cancer cells, presenting new strategies for cancer therapy.