- Journal
- COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
- Année
- 2025
- Volume
- 723
- Article
- 137370
- Mois
- OCT 20
- DOI
- 10.1016/j.colsurfa.2025.137370
Abstract
We report in this article a dynamic overcoating of a protein on gold nanoparticles (AuNP). By exploring in depth the experimental and theoretical aspects of the interactions between AuNPs, stabilized by a layer of sodium citrate (AuNP-cit), and a lectin, Concanavalin A (ConA), we highlighted a dynamic interaction between these two entities. Experiments (physicochemical characterization, fluorescence quenching of tryptophan residues of ConA, and atomic force microscopy in force mode) were run in parallel with a numerical approach using molecular dynamics (MD) to explain in detail the different aspects of the [AuNP-cit ConA] interactions. Our results were compared to the ones obtained using human serum albumin (HSA) and bare AuNP (without the sodium citrate coating) obtained via MD. The complex [AuNP-cit ConA] was of low energy non-covalent binding via electrostatic interactions (with ionic binding) and low affinity between the two partners. Additionally, ConA was not able to displace the sodium citrate corona from AuNP-cit, leading to an important electrostatic competition between the different species in the solvent. This phenomenon suggested that a dynamic overcoating of the