DL: Bio-engineered palladium nanoparticles

Metal nanoparticles have a wide range of applications in chemical catalysis, fuel cells, antimicrobial textile coatings, and have been used in nanomedical applications such as targeted cancer treatments. Such particles are currently produced by conventional chemical and physical methods that involve toxic and/or expensive chemical agents. In addition, the current chemical methods are often described as energy intensive, generally outdated, inefficient, and producing hazardous waste. Therefore, new approaches that are more environmentally friendly are in high demand. Different bacteria are able to reduce mineral salts to metals. In this project, we intend to elucidate the metabolic pathways that influence this natural process. Based on this knowledge, and using computational models, we will genetically modify bacteria to produce metal nanoparticles of desired size and shape. Using this approach, we hope to generate new materials that have a large variety of possible applications in different fields, including chemical catalysis, biomedicine, and electronics.

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Palladium nanoparticles (Pd NPs) have a wide range of applications in chemical catalysis, fuel cells, antimicrobial textile coatings, and have been used in nanomedical applications such as targeted cancer treatments. Pd NPs are currently produced by conventional chemical and physical methods that involve toxic and/or expensive chemical agents. In addition, the current chemical methods are described as energy intensive, generally outdated, inefficient, and producing hazardous waste. Therefore, new approaches that are more environmentally friendly are in high demand. Different bacteria are able to reduce Pd(II) ions to metallic Pd(0). The exact mechanism of Pd reduction and Pd nanoparticle formation is still unknown. As nanoparticles size and shape are two important parameters that have a direct effect on catalytic properties, size-controlled synthesis of Pd NPs is a highly relevant technology. In preliminary work, we were able to show that we can obtain Pd NPs of different sizes and shapes from various single-gene knockout mutants of E.coli, that also show differences in their catalytic properties. Based on this and other data, we intend to elucidate the biological pathways that lead to Pd NP formation and deposition in bacterial cells using libraries of E.coli mutants. We plan to engineer bacterial strains to make Pd NPs with tailored properties by fine-tuning their size and shape in a systems biology approach, using metabolic modelling to inform on the redox status and Pd uptake competence of the cell. Using this approach, we hope to generate new materials that have a large variety of possible applications in different fields, including chemical catalysis, biomedicine, and electronics.