Nature Communications· 2026Q1
Direct measurement of protein dipoles reveals the mechanism for like-charge adsorption on silica
- 0citations
- Q1SCImago
- 2026year
Short summary
Direct KPFM measurements show ferritin proteins adsorb to negatively charged silica surfaces via their negative end, driven by sodium cations mediating the interaction.
AI-generated from the title and abstract; the full text is not read.
Key points
- Ferritin proteins adsorb to negatively charged silica surfaces, contrary to typical electrostatic expectations.
- Direct KPFM measurements reveal a positive dipole moment for ferritin on silica, indicating the negative end faces the surface.
- Sodium cations in the buffer solution are identified as pivotal in mediating this like-charge adsorption mechanism.
- Internal iron loading modulates the protein's dipole and correlates with its rigidity, without causing structural changes.
AI-generated from the title and abstract; the full text is not read.
Abstract
Abstract Negatively charged particles are expected to adsorb with difficulty onto negatively charged surfaces. However, some proteins do. In this work, we use ferritin as a model protein particle to study its adsorption onto a negatively charged silica surface. Using Kelvin Probe Force Microscopy (KPFM), we provide direct measurement of the dipole moment of the protein ferritin on silica. The positive dipole value indicates that the negative end of the protein faces the surface. In this immobilization mechanism, our results unveil the pivotal role of sodium cations in the buffer solution. Changing the iron loading inside the ferritin, appears to add positive charges and the dipole is modulated without inducing structural changes. Comparison of quartz crystal microbalance results with KPFM reveals a strong correlation between rigidity and internal charge distribution. Our measurements provide insights on the relationship between dipole, protein adsorption, and the contribution of internal charge distribution.
The authors' abstract, as published at the source. Nature Communications, 2026 · DOI ↗
Continue with a free account
Ask the paper: 3 free questions a day about this paper; save it, get its citation, new summaries every day for your field. Takeaways are Premium.
Continue free on the webSign in with Google or Apple; no card needed. You come back to this paper.
On your phone:
Field: Surfaces, Coatings and Films
Surfaces, Coatings and FilmsMaterials Science