One-step green synthesis of gold nanoparticles using casein hydrolytic peptides and their anti-cancer assessment using the DU145 cell line

•Gold nanoparticles (AuNPs) were synthesized using casein hydrolytic peptides (CHPs) as a reducing and protecting agent.•This single-step process of production of AuNPs was free from any toxic chemicals or solvents.•CHPs played an important role in surface protection of AuNPs for a long-term period (12 months).•The in-vitro cytotoxicity assay of AuNPs demonstrated the low-viability of human prostate cancer (DU145) cell line.

This study demonstrates casein hydrolytic peptide (CHP)-mediated synthesis of crystalline gold nanoparticles (AuNPs). The AuNPs formation was triggered by the addition of an aqueous NaOH solution due to the catalytic properties of OH− and/or hydration of the functional groups of CHPs. The CHPs were capable of forming a monolayer on the AuNP surface via electrostatic interactions, thus playing an important role in long-term stability (12 months). The AuNPs resulted in lower viability in the human prostate cancer cell line as compared to the normal mouse hepatocyte cell line; this property exhibits the potential of AuNPs for applications in cancer therapy.

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