Innovative and sustainable synthesis of biogenic gold nanoparticles for cholesterol detection: gelatine role in enhanced stability and catalytic activity.

The biosynthesis of metal nanoparticles using natural extracts represents a significant advancement in quantitative analysis, as it effectively reduces nanoparticle aggregation, thereby enhancing the precision and dependability of analytical results. However, particle agglomeration of the nanoparticles continues to be a notable hurdle. In this study, for the first time, we addressed this issue by introducing gelatine into the synthesis of biogenic gold nanoparticles (AuNPs). Interestingly, although gelatine exhibits reducing properties, its primary role in this context is as an agglomeration inhibitor when combined with the natural extract. Analyses including SEM-EDS, element mapping, TEM, XRD, FT-IR, DLS, TGA-DTG, and zeta potential revealed that the incorporation of gelatine alters the morphology of biogenic AuNPs, promoting resistance to aggregation. The synthesized AuNPs have exhibited a dual-layer structure, with coatings consisting of both natural extract and gelatine. Additionally, the gelatine presence marginally enhances the intrinsic catalytic activity of AuNPs. Importantly, the gelatine coating does not compromise the efficacy of AuNPs in the colorimetric assay, partially in cholesterol detection, which demonstrated a wide-ranging detection capability of 1-1000 μM with an LOD of 3.48 μM. Furthermore, the analytical accuracy was validated using CG-FID, achieving near-perfect results in fast food samples such as snack-sticks and butter & pork floss baguettes. Hopefully, these findings in this study will not only contribute to advancements in the field of quantitative analysis but also provide valuable insights for various industries seeking sustainable methodologies for the synthesis of metallic nanoparticles.