A molecular view of peptoid-induced acceleration of calcite growth

Journal Article · 29 October 2024 · Proceedings of the National Academy of Sciences of the United States of America

DOI: https://doi.org/10.1073/pnas.2412358121 · OSTI ID:2475449

Zhang, Mingyi  ^[1]; Chen, Ying  ^[1]; Wu, Chunhui ^[2]; Zheng, Renyu ^[2]; Xia, Ying ^[3]; Saccuzzo, Emily G. ^[1]; Trinh, Thi Kim Hoang  ^[1]; Mondarte, Evan Angelo Quimada ^[1]; Nakouzi, Elias  ^[1]; Rad, Behzad  ^[4]; Legg, Benjamin A. ^[1]; Shaw, Wendy J.  ^[1]; Tao, Jinhui ^[1]; De Yoreo, James J. ^[5]; Chen, Chun-Long  ^[2]

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1. Physical Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352
2. Physical Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, Department of Chemical Engineering, University of Washington, Seattle, WA 98195
3. Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195
4. The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
5. Physical Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195

The extensive deposits of calcium carbonate (CaCO ₃ ) generated by marine organisms constitute the largest and oldest carbon dioxide (CO ₂ ) reservoir. These organisms utilize macromolecules like peptides and proteins to facilitate the nucleation and growth of carbonate minerals, serving as an effective method for CO ₂ sequestration. However, the precise mechanisms behind this process remain elusive. In this study, we report the use of sequence-defined peptoids, a class of peptidomimetics, to achieve the accelerated calcite step growth kinetics with the molecular level mechanistic understanding. By designing peptoids with hydrophilic and hydrophobic blocks, we systematically investigated the acceleration in step growth rate of calcite crystals using in situ atomic force microscopy (AFM), varying peptoid sequences and concentrations, CaCO ₃ supersaturations, and the ratio of Ca ²⁺ / HCO ₃ ⁻ . Mechanistic studies using NMR, three-dimensional fast force mapping (3D FFM), and isothermal titration calorimetry (ITC) were conducted to reveal the interactions of peptoids with Ca ²⁺ and HCO ₃ ⁻ ions in solution, as well as the effect of peptoids on solvation and energetics of calcite crystal surface. Our results indicate the multiple roles of peptoid in facilitating HCO ₃ ⁻ deprotonation, Ca ²⁺ desolvation, and the disruption of interfacial hydration layers of the calcite surface, which collectively contribute to a peptoid-induced acceleration of calcite growth. These findings provide guidelines for future design of sequence-specific biomimetic polymers as crystallization promoters, offering potential applications in environmental remediation (such as CO ₂ sequestration), biomedical engineering, and energy storage where fast crystallization is preferred.

• Sponsoring Organization: USDOE
• OSTI ID: 2475449
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Issue: 45 Vol. 121; ISSN 0027-8424
• Publisher: Proceedings of the National Academy of SciencesCopyright Statement
• Country of Publication: United States
• Language: English