Molecular Mechanistic Insights into the Ionic-Strength-Controlled Interfacial Behavior of Proteins on a TiO2 Surface
2021 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 37, no 39, p. 11499-11507Article in journal (Refereed) Published
Abstract [en]
By adjusting the ionic strengths through changing the concentration of the buffer ions, the molecular force and the interfacial behavior of cytochrome c (Cyt c) and TiO2 are systematically studied. The molecular forces determined by combining the adhesion force and adsorption capacity are found to first increase and then decrease with the increasing ionic strength, with a peak obtained at an ionic strength between 0.8 and 1.0 M. The mechanism is explained based on the dissociation and hydration of ions at the interfaces, where the buffer ions could be completely dissociated at ionic strengths of <0.8 M but were partially associated when the ionic strength increased to a high value (>1.2 M), and the strongest hydration was observed around 1.0 M. The hydrodynamic size and the zeta potential value representing the effective contact area and protein stability of the Cyt c molecule, respectively, are also affected by the hydration and are proportional to the molecular forces. The interfacial behavior of Cyt c molecules on the TiO2 surface, determined through surface-enhanced Raman scattering (SERS), is extremely affected by the ionic strength of the solution as the ion dissociation and hydration also increase the electron transfer ability, where the best SERS enhancement is observed at the ionic strength of around 1.0 M, corresponding to the largest molecular force. Our results provide a detailed understanding at the nanoscale on controlling the protein interfacial behavior with solid surfaces, adjusted by the buffer ions.
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2021. Vol. 37, no 39, p. 11499-11507
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
URN: urn:nbn:se:ltu:diva-87237DOI: 10.1021/acs.langmuir.1c01726ISI: 000705972500008PubMedID: 34549968Scopus ID: 2-s2.0-85116527166OAI: oai:DiVA.org:ltu-87237DiVA, id: diva2:1597650
Funder
Swedish Research Council
Note
Validerad;2021;Nivå 2;2021-10-13 (beamah);
Forskningsfinansiärer: Ministry of Research and Innovation of Romania (CNCS—UEFISCDI, Nr.PN-III-P4-ID-PCCF-2016-0050, within PNCDI III)
2021-09-272021-09-272021-12-13Bibliographically approved