DL: Bio-engineered palladium nanoparticles

Metallnanopartikler har en rekke bruksområder innen kjemisk katalyse, brenselceller, antimikrobielle tekstilbelegg, og har blitt brukt i nanomedisinske metoder, f.eks som målrettede kreftbehandlinger. Slike partikler fremstilles for tiden ved konvensjonelle kjemiske og fysiske metoder som involverer giftige og/eller dyre kjemiske midler. I tillegg er dagens kjemiske metoder energiintensive, utdaterte, ineffektive og produserer farlig avfall. Det er derfor stort etterspørsel etter nye tilnærminger som er mer miljøvennlige. Ulike bakterier kan omdanne mineralsalter til metaller. I dette prosjektet har vi til hensikt å belyse de metabolske rutene som påvirker denne naturlige prosessen. Basert på denne kunnskapen, og ved bruk av databeregningsmodeller, vil vi kunne genetisk modifisere bakterier for å produsere metallnanopartikler av ønsket størrelse og form. Ved hjelp av denne tilnærmingen håper vi å generere nye materialer som har et stort utvalg av mulige anvendelser på forskjellige felt, inkludert kjemisk katalyse, biomedisin og elektronikk.

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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 In addition, the current chemical methods are described as energy intensive, generally outdated, inefficient, and producing hazardous waste.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.