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MoS2

  • Guiding Peptide-driven Exfoliation and Organization of 2D Nanomaterials

    Speaker: Professor Tiffany Walsh
    Institute: Deakin University
    Country: Australia
    Speaker Link: https://www.deakin.edu.au/about-deakin/people/tiffany-walsh
    Time: 09:00 CET 23-Feb-22

    Professor Tiffany Walsh

    Institute for Frontier Materials, Deakin University, Australia

    Peptides provide a versatile platform for the generation and organization of nanomaterials in liquid water. However, their application and use on two dimensional (2D) nanosheet structures such as graphene, h-BN and MoS2 is hampered, due to a lack of fundamental data regarding the structure/function relationships of these bio-nano interfaces. Together with experimental characterization, molecular simulations can provide complementary insights into these challenging interfaces. Here, our strategy uses bioconjugate hybrids of peptides and fatty acids to exfoliate materials into 2D nanosheets in aqueous media. The role of molecular simulations in revealing the molecular scale characteristics of the peptide-driven exfoliation process are discussed for graphene, particularly in the role of the fatty acids in reducing defects in the exfoliated material. Umbrella sampling simulations are also used to provide unprecedented insights into both the peptide-driven exfoliation and suspension mechanisms. Key to our progress here are advancements in our simulation strategy to model peptide/h-BN and peptide/MoS2 interfaces. This involved development of interfacial force-fields for describing bio-interactions at h-BN and MoS2nanosheet interfaces in aqueous media, based on first-principles calculations. Replica-exchange with solute tempering (REST) molecular dynamics (MD) simulations are used to explore the contact between the peptides and the nanosheets, to guide the design of effective bioconjugates for exfoliation and assembly. The outcomes of our simulations provide a strong foundation for future work to design and deploy these molecular bioconjugates in the self-assembly of 2D heterostructures.

    References:

    1. D. Parab, A. Budi, J. M. Slocik, R. Rao, R. R. Naik, T. R. Walsh,  M. R. Knecht, J. Phys. Chem. C, 124, 2219-2228 (2020).

    2. Brljak, A. D. Parab, R. Rao, J. M. Slocik, R. R. Naik, M. R. Knecht, T. R. Walsh, Chem. Commun.,56, 8834-8837, (2020).

    3. D. Parab, A. Budi, N. Brljak, M. R. Knecht, and T. R. Walsh, Adv. Mater. Interfaces, 8, 2001659 (2021).

    4. D. Parab, R. Dureja, R. Rao, J. M. Slocik, R. R. Naik, T. R. Walsh and M. R. Knecht, Langmuir, 37, 1152-1163 (2021).

    5. N. Pham and T. R. Walsh, Chem. Commun., 57, 3355-3358 (2021).

    6. Brljak, R. T. Jin,  T. R. Walsh, and M. R. Knecht, Nanoscale, 13, 5670-5678 (2021).

    7. T. Jin, F. Vuković and T. R. Walsh, J. Phys. Chem. Lett., in press