Collagen Capping Augments Functional Properties to Gold Nanoparticles

The present study aims to augment the functional properties of gold nanoparticles by capping them with natural type III collagen extracted from the avian intestine. Collagen-capped gold nanoparticles (C-AuNPs) were synthesised by mixing extracted collagen (1 mg/ml in 0.05 mM acetic acid) and auric chloride (at 5 mM concentration) at 9:1 ratio and incubated at room temperature. No external agents are involved in the synthesis. The visible colour change and surface plasmon resonance spectrum confirm the formation of C-AuNPs. The size of the C-AuNPs measured ranges between 10.56 ± 1.0 nm. C-AuNPs display significant antimicrobial and antioxidant activities when tested with the chosen microorganisms. C-AuNPs demonstrate high storage stability with the biological properties retained for more than 120 days of storage at 4 °C. In addition, C-AuNPs exhibit photocatalytic activity when tested in the dye solution under sunlight. Thus, capping with collagen augments the storage stability of gold nanoparticles with nil aggregations, which are the added properties suitable for biomedical and environmental applications.