Dissolution, Agglomerate Morphology, and Stability Limits of Protein-Coated Silver Nanoparticles
Matthew N. Martin, Andrew J. Allen, Robert I. MacCuspie, Vincent A. Hackley
Little is understood about the impact coating molecules have on nanoparticle dissolution kinetics and intermediate agglomerate formation in a dilute nanoparticle dispersion. Dissolution and agglomeration processes compete in removing isolated nanoparticles from the dispersion, making quantitative time-dependent measurements of the mechanisms of nanoparticle loss particularly challenging. In this paper, we present in situ ultrasmall-angle X-ray scattering (USAXS) results, simultaneously quantifying dissolution, agglomeration, and stability limits of silver nanoparticles (AgNPs) coated with bovine serum albumin (BSA) protein. When the BSA corona is disrupted, we find that the loss of silver from the nanoparticle core is well matched by a second order kinetic rate reaction, arising from the oxidative dissolution of silver. Dissolution and agglomeration are quantified and morphological transitions throughout the process are qualified. By probing the BSA-AgNP suspension around its stability limits, we provide insight into the destabilization mechanism, by which individual particles rapidly dissolve as a whole rather than undergo slow dissolution from the nanoparticle surface, once the BSA layer is breached. Since USAXS rapidly measures over the entire nanometer to micrometer size range during the dissolution process, many insights are also gained into the stabilization of NPs by protein, and its ability to protect the reactive metal core from the solution environment. This approach can be extended to a wide variety of coating molecules and metal nanoparticle systems to carefully survey their stability limits, revealing the likely mechanisms of coating breakdown and ensuing reactions.
, Allen, A.
, MacCuspie, R.
and Hackley, V.
Dissolution, Agglomerate Morphology, and Stability Limits of Protein-Coated Silver Nanoparticles, Langmuir, [online], https://doi.org/10.1021/la502973z, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=914386
(Accessed June 5, 2023)