An area of growing interest is the development of noble-metal metamaterials because of their unique properties[1,2]. Development of versatile generation strategies for production of these metamaterials remains challenging; these materials comprise assemblies of nanoparticles of different compositions, arranged in 3-D arrays; fine control over the interparticle spacings in these arrays is essential. It is also highly desirable that these arrays can be dynamically reconfigured. As the first steps towards realizing these goals, we investigate Au- and Ag-binding peptide sequences conjugated with light-switchable azobenzene moieites, for the purpose of designing stimuli-responsive biomolecule linkers that can ultimately facilitate assembly of different types of nanoparticles into 3D arrays. Here, we use advanced sampling molecular dynamics simulations to investigate the molecular conformations and materials-binding properties of these molecules. These peptide sequences have a light sensitive thiol-maleimide azobenzene thiol-maleimide (MAM) unit conjugated onto either the N- or the C-terminus of the peptide. We have also carried out well-tempered meta-dynamics simulations to estimate the free energy of binding, of the MAM unit alone, at the Au and Ag aqueous interfaces. Our results indicate that the MAM unit binds more strongly at Au compared with Ag, with the trans conformation of the MAM binding more strongly than the cis for both metals. Our simulations of the N- and C-conjugated peptides reveal that the presence of the MAM unit can significantly affect the adsorbed structures and conformational dynamics of the surface adsorbed peptide. Our findings provide guidance in the design and development of a stimuli-responsive biomolecule linker for nanoparticle assembly purposes.
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