TY - JOUR

T1 - Role of Water during the Early Stages of Iron Oxyhydroxide Formation by a Bacterial Iron Nucleator

AU - Qi, Daizong

AU - Lukić, Miodrag J.

AU - Lu, Hao

AU - Gebauer, Denis

AU - Bonn, Mischa

N1 - Funding Information: The authors are grateful for the financial support from the MaxWater Initiative of the Max Planck Society. This research was partly (M.J.L. and D.G.) funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – GE 2278/12-1.

PY - 2024/2/1

Y1 - 2024/2/1

N2 - Understanding the nucleation of iron oxides and the underlying hydrolysis of aqueous iron species is still challenging, and molecular-level insights into the orchestrated response of water, especially at the hydrolysis interface, are lacking. We follow iron(III) hydrolysis in the presence of a synthetic bacterial iron nucleator, which is a magnetosome membrane specific peptide, by using a constant pH titration technique. Three distinct hydrolysis regimes were identified. Interface-selective sum frequency generation (SFG) spectroscopy was used to probe the interfacial reaction and water in direct contact with the peptide. SFG data reveal that iron(III) species react quickly with interfacial peptides while continuously enhancing water alignment into the later stages of hydrolysis. The gradually aligning water molecules are associated with initially promoted (regimes I and II) and later suppressed (regime III) hydrolysis after the saturation of water alignment has occurred until regime II. These interfacial insights are crucial for understanding the early stage of iron oxide biomineralization.

AB - Understanding the nucleation of iron oxides and the underlying hydrolysis of aqueous iron species is still challenging, and molecular-level insights into the orchestrated response of water, especially at the hydrolysis interface, are lacking. We follow iron(III) hydrolysis in the presence of a synthetic bacterial iron nucleator, which is a magnetosome membrane specific peptide, by using a constant pH titration technique. Three distinct hydrolysis regimes were identified. Interface-selective sum frequency generation (SFG) spectroscopy was used to probe the interfacial reaction and water in direct contact with the peptide. SFG data reveal that iron(III) species react quickly with interfacial peptides while continuously enhancing water alignment into the later stages of hydrolysis. The gradually aligning water molecules are associated with initially promoted (regimes I and II) and later suppressed (regime III) hydrolysis after the saturation of water alignment has occurred until regime II. These interfacial insights are crucial for understanding the early stage of iron oxide biomineralization.

UR - http://www.scopus.com/inward/record.url?scp=85184135121&partnerID=8YFLogxK

U2 - 10.1021/acs.jpclett.3c03327

DO - 10.1021/acs.jpclett.3c03327

M3 - Article

C2 - 38253017

AN - SCOPUS:85184135121

VL - 15

SP - 1048

EP - 1055

JO - Journal of Physical Chemistry Letters

JF - Journal of Physical Chemistry Letters

SN - 1948-7185

IS - 4

ER -