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Bioinspired approaches represent emerging methods for the fabrication and application of nanomaterials under desirable ambient conditions. By adapting biomimetic processes to technological applications such as catalysis, new directions could be achieved for materials that are reactive under energy efficient and ecologically friendly conditions. Such materials have been prepared using a self-assembling peptide template in which non-spherical Pd nanostructures can be generated. Based upon the Pd/peptide ratio, different inorganic morphologies can be prepared within the peptide scaffolds, including nanoparticles, linear nanoribbons, and complex nanoparticle networks (NPNs). These materials are catalytically reactive; however, the effects of the template and Pd morphology remain poorly understood. To ascertain these effects, we present an in depth catalytic analysis of the bioinspired peptide-based system using two vastly different reactions: Stille C−C coupling and 4-nitrophenol reduction. For all of the systems studied, enhanced reactivity was observed for the Pd nanoparticles and NPNs over the nanoribbons. This effect is suggested to arise from two key structural characteristics of the materials: the amount of inorganic surface area and the penetration depth within the peptide scaffold. Such results are important for the design and development of selective nanocatalytic systems, where the composite structure works in conjunction to mediate the overall activity.

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Diverse classes of metallic nanostructures have been explored recently for a variety of applications, including energy efficient catalytic transformations. The morphology, size, and local chemical environment of the catalytic nanomaterials can have dramatic effects on their reactivity. Herein, we demonstrate a peptide-template-based approach for the synthesis of Pd and Pt nanostructures of varying morphologies under ambient conditions. In this report, we examine the effect of the metal/peptide ratio over an expansive range to demonstrate the stepwise production of materials ranging from nanospheres to nanoparticle networks for the Pd structures. Interestingly, when the metallic composition was changed to Pt, only spherical materials were generated, indicating that the metallic composition of the nanostructures plays a key role in the final morphology. The hydrogenation of allyl alcohol was then employed as a model reaction to examine the catalytic reactivity of these metallic nanomaterials. Under environmentally benign reaction conditions, high turnover frequency values were observed for the metallic Pd and Pt nanocatalysts that was independent of the material morphology. Given their high degree of reactivity and facile synthetic preparation, these materials could prove to be versatile and efficient catalysts for a variety of industrially and environmentally important reactions.

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Bio-inspired-based methods represent new approaches for the fabrication and activation of nanomaterials, all under ambient and energy-neutral conditions. Recent advances have demonstrated the production of non-spherical materials of Pd and Pt; however, the production of similar Au materials remains challenging. Such fabrication routes are highly important as Au-based nanomaterials of selectable morphologies could have immediate applications in catalysis and energy storage. In this contribution, we demonstrate a peptide template-based methodology for the fabrication of Au nanoparticle networks, which are highly branched linear structures that are prepared in water at room temperature. The materials were fully characterized using UV-vis, TEM, XRD, and DLS, from which their catalytic activity was subsequently studied for the reduction of 4-nitrophenol. Using this approach, the materials were shown to be highly reactive as compared to comparable structures, which is likely due to their unique biological template. Together, this research represents a step forward in bio-based methodologies for the fabrication of functional and potentially sustainable materials.

Magnetic iron oxide nanoparticles have been well known for their applications in magnetic resonance imaging (MRI), hyperthermia, targeted drug delivery, etc. The surface modification of these magnetic nanoparticles has been explored extensively to achieve functionalized materials with potential application in biomedical, environmental and catalysis field. Herein, we report a novel and versatile single step methodology for developing curcumin functionalized magnetic Fe3O4 nanoparticles without any additional linkers, using a simple coprecipitation technique. The magnetic nanoparticles (MNPs) were characterized using transmission electron microscopy, x-ray diffraction, fourier transform infrared spectroscopy and thermogravimetric analysis. The developed MNPs were employed in a cellular application for protection against an inflammatory agent, a polychlorinated biphenyl (PCB) molecule.

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