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Bimetallic nanoparticles have attracted increasing scientific and technological interest as modules for creating nanoscale materials with unique magnetic, electronic, and chemical properties. The properties of bimetallic NPs are functions of... 

Bio-inspired approaches for materials synthesis and application are emerging as potentially sustainable approaches to achieve functional structures with selectively controlled properties (e.g., turn on catalysis). An attractive avenue to allow for selective functionality is optical stimulation; however, the ability to make nanomaterials light responsive for many applications remains challenging. One approach is to incorporate photoswitches into the surface adsorbed ligands which can stimulate a surface structural change that could have implications on the catalytic reactivity driven by the underlying metallic nanoparticle component. Herein were demonstrate the ability to drive optical switching of surface ligand overlayer structures on peptide-capped Pt nanoparticles. To this end, incorporation of an azobenzene unit into the surface-adsorbed peptide allows for the ability to optical reconfigure the ligand overlayer structure. This change results in direct manipulation of the catalytic properties of the Pt materials for olefin hydrogenation, which demonstrated changes in reactivity not only between different reagents, but also between the different ligand structures. Such results present information which could be used in the design of ligand interface structures to trigger specific reactivity control for a variety of reactions and materials for sustainable catalysis. 

Peptides respresent intriguing materials to achieve sustainable catalytic reactivity that mimic the natural functions of enzymes, but without the limitations of temperature/solvent sensitivity. They could also be applicable to a wide variety of substrates, thus expanding their potential use at different reaction levels ranging from the benchtop to industrial. Unfortunately, signfiicant use of catalytic peptides remains limited due to the general lack of understanding of the fundamental basis of their inherent reactivity. In this contribution, we examine the reactviity of a peptide (termed CPN3) previously isolated with ester hydrolysis reactivity. It is demonstrated that the system is most reactive under slightly basic conditions. While the system is slower than comparable enzymes, it demonstrates signficiant reactivity across multiple substrates and different reaction conditions that coud likely lead to enzymatic denaturation. In addition, key active site residues were identified to begin to elucidate the fundamental basis of the reactivity. Such results could be used to design new sequences with enhanced reactivity under sustainable conditions. 

The realization of multifunctional nanoparticle systems is essential to achieve highly efficient catalytic materials for specific applications; however, their production remains quite challenging. They are typically achieved through the incorporation of multiple inorganic components; however, incorporation of functionality could also be achieved at the organic ligand layer. In this work, we demonstrate the generation of multifunctional nanoparticle catalysts using peptide-based ligands for tandem catalytic functionality. To this end, chimeric peptides were designed that incorporated a Au binding sequence and a catalytic sequence which can drive ester hydrolysis. Using this chimera, Au nanoparticles were prepared, which sufficiently presented the catalytic domain of the peptide to drive tandem catalytic processes occurring at the peptide ligand layer and the Au nanoparticle surface. This work represents unique pathways to achieve multifunctionality from nanoparticle systems tuned by both the inorganic and bio/organic components, which could be highly important for applications beyond catalysis, including theranostics, sensing, and energy technologies.